Applying Mechatronics to Promote Science / Central Brooklyn Robotics Initiative (AMPS / CBRI)

**Cityscape creations**

**Summary:** Students will work in groups to design and construct a building from LEGOs, based on design principles which aim at creating a stable structure. The students will learn basic LEGO building principles, like make a wide and heavy base and stable connections between pieces, and will use this knowledge to design a building. Students will plan extensively, and after constructing the building, assess the motivation for making changes from or adhering to their original design.

Complete Activity (pdf) | Worksheet (pdf)

**Discovering Phi: The Golden Ratio**

**Summary:** Students discover the mathematical constant phi in two hands-on activities. First, the students measure lengths indicated in pictures of "natural" objects-like bones in the human hand, a nautilus shell, a star-and form ratios of the measured values, which are close to phi. Next, the students learn a basic definition of a mathematical sequence, and specifically the Fibonacci sequence. By taking ratios of successive terms of the sequence, they again find numbers close to phi. This activity is facilitated by using a square puzzle that creates an approximate Fibonacci spiral. Lastly, the instructor implements the rule of the Fibonacci sequence in the Lego robot from the Teach Engineering activity, Fibonacci's Robots, that is equipped with a pen. The robot draws a Fibonacci spiral that is similar to the nautilus.

Teachengineering.org | Complete Activity (pdf) | Worksheet (pdf)

**Fastastic Frequencies**

**Summary:** Students will use a resistor- capacitor circuit to explore the concept of frequency. Students will learn to build with resistors, capacitors, and light emitting diodes on a prototyping board. By investigating the formula for the time constant of the system, students will be able to explore the physical concept of frequency.

**The Fibonacci Sequence & Robots**

**Summary:** Using the LEGO NXT Robotics kit, students learn how to build and program a robot. Students are assigned roles, consisting of group leader, chassis builder, arm builder, chief programmer, and Fibonacci verifier. By building a robot that moves based on the Fibonacci sequence of numbers, the students can visualize how quickly the numbers in the sequence grow. Programming the robot to move according to these numbers allow the students to break down the sequence into simple algebraic equations, so that a computer can understand the Fibonacci sequence.

Teachengineering.org | Complete Activity (pdf) | Worksheet (pdf)

**Greenhouse Gases**

**Summary:** Students will record as a class the change in readings from two temperature probes under a lamp, one inside and one outside a clear glass jar. Students plot the recorded data on two coordinate axes and identify trends for each probe. Students relate this finding as an illustration of the discussion of greenhouse gases.

Complete Activity (pdf) | Worksheet (pdf)

**Newton's Law of Cooling**

**Summary:** This activity demonstrates the exponential trend in the heating and cooling of a beaker of water. This task is accomplished by first appealing to the students' real-life experiences with heating, and by giving an example of an exponential curve. Next, the basic principles of heat transfer are discussed. Using this information, the students can make predictions about the heating and cooling curves of a beaker of water of different temperatures in the same ambient environment. By conducting the simple experiment of a beaker in a water bath, the temperature over time is recorded and different heating and cooling curves are created. These can then be recognized as having exponential trends, which verifies Newton's result.

Teachengineering.org | Complete Activity (pdf) | Worksheet (pdf)

**Parabolic Projectile Paths**

**Summary:**Students use a ball launcher to study projectile motion. By using a LEGO NXT brick and light sensor to make a photogate and Mindstorms software with real-time data logging, students can measure the time of flight for a ball. Students use these data to estimate the maximum height attained by the ball by simultaneously solving three algebraic equations.

Complete Activity (pdf) | Worksheet (pdf) | Building Instructions (pdf)

**Battle Bots**

**Summary:** This lesson introduces students to torque, power, friction, and gear ratio. Two students/teams modify a robotic Lego vehicle by changing its gear ratio, wheel, size, weight, and engine power. Students are given a certain amount of points to spend on modifications. An upgrade in gear ratio or wheel size will result in a larger amount of points being deducted from their total. These robots are then put on a track opposite each other with a rope attaching one to the other. The robot with the right adjustments will pull the other robot across a line signifying it has won.

Teachengineering.org | Complete Activity (pdf)

**Force Measurements and Applications**

**Summary:**This activity focuses on allowing children to qualitatively and quantitatively understand the concepts of forces and springs and their inherent linear relationship. The students will perform a basic experiment in groups and be guided through the simple analysis of the data they gather.

**Newtons Law’s: Measuring “g”**

**Summary: **The purpose of this experiment is to test whether Force = Mass x Acceleration. The technique will be similar to that used to measure g in lab 2. You will use the weight of a small mass, m, to provide the force that accelerates a system consisting of a large mass, M, the air cart + the aluminum “flag,” and the small mass, m. If friction can be neglected, 1. (M + m) a = mg or 2. a = (mg)/(M + m). You will measure m, M and a to see if the measured acceleration really is given by the above equation, i.e. does ameasured = atheory where the theoretical value is given by the equation above, using the measured masses and g = 9.80 m/s2. You will measure the acceleration, a, by recording the time the flag passes the sensors on the air track, the distance between those points and computing the velocity and then the acceleration of the cart. The computer will record the times; you will measure the distances and compute the velocities and acceleration.

**Chemical Wonders, L1, Activity: The Nano-Scale**

**Summary:** Working individually in this activity the students will investigate objects at the nanometer level. First the students will conceptualize scaling, drawing analogies from monetary and distance platforms. Next, the students will be introduced to the prefix “nano” and how it relates to distance. They will then use a multimedia interface to reinforce the concept of scaling and visual objects on a nanometer scale. Finally, as homework the students will be asked to investigate currently developed nano-scale machines; discuss potential applications for these devices, limitations and potential design problems which may occur at this scale.

**Chemical Wonders, L1, Activity: The Plastic Test**

**Summary:** Students are presented with a brief history of plastics and examine the abundance of different types of plastics found in our day-to-day lives. They will be introduced to the mechanical properties of plastics which make them useful for industrial applications including: stress/strain relationship. These physical properties allow for plastics to be fabricated into different products. Students will be able to recognize the different roles that plastics play in our lives and the effects that plastics have on our environment. Finally, the students will act like industrial engineers and based on the cost and physical properties, they will determine which plastics will be the most cost effective for given applications.

**Motion Commotion, L1, Activity 1:Differential Gears**

**Summary:** The goal of this activity is to teach elementary school students how differential gears work and how they can be constructed using a LEGO NXT ® kit. The students will construct two different chassis; one with a gear differential and one without. They will then experiment with turning and discuss different styles of gears and how they can be used for different functions.

**Automated Image Scanner**

**Summary:** This activity introduces students to the processes involved in automated image scanning via a scanning bed. The scanner itself consists of a LEGO Mindstorms Light Sensor mounted to a traversing xy-stage, all connected to and controlled by a LEGO Mindstorms NXT intelligent brick. After students fill out a 7x7 grid, drawing whatever pattern/image they wish, the image is then scanned by the machine. The image data is then offloaded from the brick into the Processing programming environment whereby their image is rendered and displayed on a computer screen.

Complete Activity (pdf) | Worksheet (pdf)

**Fluid Flow Rate with LEGO NXT**

**Summary:**his activity will introduce students to the concepts of flow rate and its dependency on pipe diameter. By attaching pipe fitting of various orifice diameters to a simple flow system, students discover what effects the differences in diameter have on the flow rate of the system. While the effects are readily seen by mere observation, students will learn to quantitatively measure the flow rate via the use of LEGO sensors to determine the time it takes to fill a container between two discrete points.

Complete Activity (pdf) | Pre Evaluation (pdf) | Post Evaluation (pdf)

**Arctic Animal Robot**

**Summary:** In this activity students will create a four-legged walking robot and measure how far it travels across different types of land surfaces. Students will modify the feet and observe the effect of their modifications on its net distance across the different types of surfaces. The activity will illustrate the manner in which different species might have specialized locomotive features which allow them to survive or thrive in their habitat environments. Students typically observe the difference between the control walker and the walker with prescribed modifications and record the results; if there is sufficient time and interest students can design and test their own modifications. Students compare the distance covered in 30 steps for each modification. Students are encouraged to use their imagination or look to real life creatures that thrive in similar types of landscape for inspiration.

Teachengineering.org | Complete Activity (pdf) | Pre Evaluation (pdf) | Post Evaluation (pdf)

**Runaway Train: Investigating Speed with Photo Gates**

**Summary:** In this activity, students conduct an experiment to determine the relationship between the speed of a wooden toy subway car at the bottom of an incline and the height at which it is released. They observe how the photo gate-based speedometer instrument is used to "clock" the average speed of an object. Students tabulate the results and create a graph plotting the measured speed in centimeters per second against start height in centimeters. After the experiment, students design a brake to keep the speed of the cart at the bottom of the hill over a specified minimum speed and under a specified maximum speed.

**100101: What Is Binary?**

**Summary:** Working as a team, students discover the basic concepts of binary numbers and their significance in digital electronic circuitry. Each team designs and builds a basic stamp model that will convert binary numbers into decimal. The binary number will be represented by four push buttons, where each push button represents a binary place value. This model will only convert up to decimal number 15. The result of the conversion will be displayed on the screen. Students testing their work will need to convert by hand and verify the result against the model. Hence, students learn how to convert decimal number to binary using the concept of place value.

**Lets Take a Slice of Pi**

**Summary:** Working as a team, students discover that the value of pi (3.1415926...) is a constant and applies to all different sized circles. The team builds a basic Lego robot and programs it to travel in a circular motion. The robot is required to have a marker/highlighter attached to the chassis so that while the robot travels the programmed circular path, a circle can be traced on ground. Using students' measurement skills, they measure the circumference and diameter of the circle and calculate pi via the pi and circumference relationship; circumference of a circle divided by the diameter is the value of pi.

Teachengineering.org | Pre Activity Worksheet (pdf) | Pre Activity Worksheet Answers (pdf)

**Potential vs. Kinetic Energy**

**Summary:** Working as a team, students learn about two energy forms, potential and kinetic energy, using the Lego Mindstorm kit. Potential energy is a form of stored energy that can be converted to kinetic once the object or system is set in motion. For example, when a roller coaster is at the top of the hill, the system has in within it potential energy. As the coaster’s brake is let go, it will travel down the slope, all the while converting the stored potential energy to motion, known as kinetic energy. Equations can be used to relate the two forms of energy and this activity will explore the equations along with hands on Lego activity.

Complete Activity (pdf) | Worksheet (pdf)

**Triangle Inequality Theorem**

**Summary:** Working as a team, students discover that any side of a triangle is always shorter than the sum of the other two sides; known as the triangle inequality. Each team builds a basic Lego robot that is programmed to travel along a triangle. The triangle is made of electrical tape that is taped onto the ground. Students have to note that the time it takes for the robot to travel any two sides of a triangle (Case 1) is longer than the remaining third side of the triangle (Case 2). This is true given that for both cases, the robot is traveling at the same motor speed. From this activity, students learn of the parameters that makes a triangle a "valid" triangle; namely the triangle inequality theorem. At the same time, with the use of Lego robot, they learn of motor speed through the use of distance and time.

Complete Activity (pdf) | Worksheet (pdf)

**Velocity With Baseball-Bot**

**Summary:**Working as a team, students learn the important concept of velocity using the Lego Mindstorm kit. Velocity consists within it a two-part information; speed and direction of travel. This is a hands-on activity where two light sensors are employed as the time keeper. The distance between the two light sensors is a known value; i.e. measured with a measuring tape. From measuring the elapsed time for an object to travel a known distance, one can calculate the estimated speed of the moving object. With a defined direction, the speed can be translated to velocity.

Complete Activity (pdf) | Worksheet (pdf) | Building Instructions (pdf)

**Timing a Speedbot!**

**Summary:** Students work in groups using a timer or stopwatch to measure the speed of an NXT robot. The robot can be started and stopped by using a touch sensor and it is programmed to display the distance it has traveled in centimeters after it stops. Using the gathered data, students complete a worksheet to determine the mean speed of an NXT robot at a given motor power.

Teachengineering.org | Complete Activity (pdf) | Worksheet (pdf) | Pre Evaluation (pdf) | Post Evaluation (pdf)

**The Balancing Act**

**Summary:** Students are given the opportunity to visualize and interact with concepts they have already learned, specifically algebraic equations and solving for unknown variables. Students construct a balancing seesaw system (LEGO® Balance Scale) made from LEGO MINDSTORMS® parts and digital components to mimic a balancing scale. They are given sample algebraic equation problems to analyze, configure onto the balance scale, and evaluate by manipulating LEGO pieces and gram masses that represent terms of an equation such as unknown variables, coefficients and integers. Digital light sensors, built into the LEGO Balance Scale, detect any balance or imbalances displayed on the balancing scale. The LEGO Balance Scale interactively issues out a digital indication of balance or imbalance within the system to students. If unbalanced, students are encouraged to continue using the LEGO Balance Scale until they're correct and confident in their understanding of solving for algebraic equations. The goal of this activity is for each student to be encouraged and confident in solving algebraic equations by fundamentally understanding the basics of algebra and real-world algebraic applications.

**Renewable Energy Design: Wind Turbines**

**Summary:** Students are introduced to renewable energy, including its relevance and importance to our current and future world. They learn the mechanics of how wind turbines convert wind energy into electrical energy and the concepts of lift and drag. Then they apply real-world technical tools and techniques to design their own aerodynamic wind turbines that efficiently harvest the most wind energy. Specifically, teams each design a wind turbine propeller attachment. They sketch rotor blade ideas, create CAD drawings (using Google SketchUp) of the best designs and make them come to life by fabricating them on a 3D printer. They attach, test and analyze different versions and/or configurations using a LEGO wind turbine, fan and an energy meter. At activity end, students discuss their results and the most successful designs, the aerodynamics characteristics affecting a wind turbine's ability to efficiently harvest wind energy, and ideas for improvement. The activity is suitable for a class/team competition. Example 3D rotor blade designs are provided.

**Friction Force**

**Summary:** Students use LEGO® MINDSTORMS® robotics to help conceptualize and understand the force of friction. Specifically, they observe how different surfaces in contact result in different frictional forces. A LEGO robot is constructed to pull a two-wheeled trailer made of LEGO parts. The robot is programmed to pull the trailer 10 feet and trial runs are conducted on smooth and textured surfaces. The speed and motor power of the robot is kept constant in all trials so students observe the effect of friction between various combinations of surfaces and trailer wheels. To apply what they learn, students act as engineers and create the most effective car by designing the most optimal tires for given surface conditions.

**On-Track Unit Conversion**

**Summary:** Students use three tracks marked on the floor, one in yards, one in feet and one in inches. As they start and stop a robot specific distances on a "runway," they can easily determine the equivalent measurements in other units by looking at the nearby tracks. With this visual and physical representation of the magnitude of the units of feet, yard and inches, students gain an understanding of what is meant by "unit conversion." They also gain a familiarity with different common units of measurement. They use multiplication and division to verify their physical estimated unit conversions. Students also learn about how common and helpful it is to convert from one unit to another in everyday situations and for engineering purposes. This activity helps students make the abstract concept of unit conversion real so they develop mental models of the magnitude of units instead of applying memorized conversion factors by rote.

Teachengineering.org | Complete Activity (pdf) | Data Sheet (pdf) | Pre Evaluation (pdf) | Post Evaluation (pdf)

**Robo Clock**

**Summary:** Students learn various topics associated with the circle through studying a clock. These topics include reading analog time, understanding the concept of rotation (clockwise vs. counter-clockwise), and identifying a right angle and a straight angle within a circle. Many young students have difficulty telling time in analog format, especially with decreasing presence of analog clocks compared with digital clocks. Problems encountered in classroom include converting time written in words to a number format. For example, students have trouble making the connection between "quarter of an hour" to 15 minutes. Students also find it difficult to convert "quarter of an hour" to the number of degrees this corresponds to in a circle. This activity incorporates a LEGO® MINDSTORMS® NXT robot to help students distinguish and visualize the differences in clockwise vs. counter-clockwise rotation and right vs. straight angles, while learning how to tell time on an analog clock. To promote team learning and increase engagement, students work in teams to program and control the robot.

**Rock, Paper, Scissors Probability!**

**Summary:** Students learn about probability through a LEGO® MINDSTORMS® NTX-based activity that simulates a game of "rock-paper-scissors." The LEGO robot mimics the outcome of random game scenarios in order to help students gain a better understanding of events that follow real-life random phenomenon, such as bridge failures, weather forecasts and automobile accidents. Students learn to connect keywords such as certainty, probable, unlikely and impossibility to real-world engineering applications.

Teachengineering.org | Worksheet (pdf)

**States of Matter**

**Summary:**Students act as chemical engineers and use LEGO® MINDSTORMS® NXT robotics to record temperatures and learn about the three states of matter. Properties of matter can be measured in various ways including volume, mass, density, and temperature. Students measure the temperature of water in its solid state (ice) as it is melted and then evaporated.

**Stretching to Compare Properties: The Plastic Test**

**Summary:**After a brief history of plastics, students look more closely as some examples from the abundant types of plastics found in our day-to-day lives. They are introduced to the mechanical properties of plastics, including their stress-strain relationships, which determine their suitability for different industrial and product applications. These physical properties enable plastics to be fabricated into a wide range of products. Students learn about the different roles that plastics play in our lives, Young's modulus, and the effects that plastics have on our environment. Then students act as industrial engineers, conducting tests to compare different plastics and performing a cost-benefit analysis to determine which are the most cost-effective for a given application, based on their costs and measured physical properties.

**Accelerometer: Centripetal Acceleration**

**Summary:** Students will work as physicists to understand centripetal acceleration concepts. They will also learn about a good robot design and the accelerometer sensor. They will learn about centripetal acceleration/ force is governed by the radius between the motor and accelerometer. They will also learn about how the mass plays an important role in the centripetal acceleration/ force. It is important for students to learn about how graph their own data.

Teachengineering.org | Complete Activity (pdf) | Worksheet (pdf) | Pre Evaluation (pdf) | Post Evaluation (pdf)

**Deformation: Foam Compression**

**Summary:** Students will work as engineers and learn to conduct controlled experiments by changing one experimental variable at a time and study its effect on the outcome of the experiment. Specifically, they will conduct experiments to determine the amount of motor rotations it takes to compress a soft nanocomposite such as foam, marsh mellow and possibly dough. Students will measure the length and width of the object and also measure the change in length and width as a function of motor rotations to compress the object. Students will look at different objects and understand how they can compress a material.

Complete Activity (pdf) | Worksheet (pdf)

**Deformation: Nanocomposite Compression**

**Summary:** Students learn about nanocomposites, compression and strain as they design and program robots that compress materials. Student groups conduct experiments to determine how many LEGO® MINDSTORMS® NXT motor rotations it takes to compress soft nanocomposites, including mini marshmallows, Play-Doh®, bread and foam. They measure the length and width of their nanocomposite objects before and after compression to determine the change in length and width as a function of motor rotation.

**Force: Determing the Force Needed to Tear Different Breads**

**Summary:** Students will work as engineers and learn to conduct controlled experiments by changing one experimental variable at a time and study its effect on the outcome of the experiment. Specifically, they will conduct experiments to determine the amount of force that is required to break different kinds of breads. First, the students will assemble a robot that can pull the bread apart. Second, they will design a program in NXT MindStorm that will cause the robot to pull apart the bread. Third, using Image 3 as a guide, students will setup their experiment for pulling the bread apart. Fourth, using a physics-based formula, they will calculate the amount of force it takes to pull apart the bread to a given distance. Fifth, they will change the amount of power delivered by the bread-pulling robot and use the same physics-based formula to calculate the force it takes to pull apart the bread to a given distance. Sixth, they will determine the force needed to pull apart the bread to different distances. Finally, students will determine the amount of force it takes to pull apart different types of bread.

Complete Activity (pdf) | Worksheet (pdf)

**Gears: Determing the Angular Velocity**

**Summary:** Students will work as engineers and learn to conduct controlled experiments by changing one experimental variable at a time and study its effect on the outcome of the experiment. Specifically, they will conduct experiments to determine the angular velocity for a gear train with varying gear ratios and lengths. First, the students will assemble a robot with various size gears in a gear train. Second, they will design a program in NXT MindStorm that will cause the motor to rotate all the gears in the gear train. Third, students will use MindStorms Data Logging Program to setup their experiment with the light sensors. Fourth, they will run the program with the motor and the light sensor at the same time. Fifth, they will analyze the plot from MindStorms Data Logging Program and determine the angular velocity with a physics based formula. Sixth, they will manipulate the gear train with different gears and different lengths. Finally, students will analyze all these factors and figure out which manipulation has a higher angular velocity.

Teachengineering.org | Complete Activity (pdf)

**Molecules: The Movement of Atoms**

**Summary:** Students will work as engineers and learn about the properties molecules and how they move in 3D space. They will learn about these concepts through the robotic movements of the molecules and the robotic sensors. The concepts that are learned will cover the size of atoms, newman projections, and the relationship energy and strain on an atom. The information they gather from this activity will allow them to handle rigorous molecular modeling programs.

Teachengineering.org | Complete Activity (pdf) | Worksheet (pdf) | Pre Evaluation (pdf) | Post Evaluation (pdf)

**Tension: Breaking Through the Door**

**Summary:** Students will work as engineers and learn about the properties of four wheel drive vehicles. They will also learn about a good robot design, properties of tension and traction. They will learn about trial and error and the amount of trial and error it takes to have the robot maneuver through the door with tension. It is important for students to learn about the amount of time it takes to design a good robot to complete a task.

**Trebuchet: Determing How Far Each Object Will Go**

**Summary:** Students will work as engineers and learn to conduct controlled experiments by changing one experimental variable at a time and study its effect on the outcome of the experiment. Specifically, they will conduct experiments to determine the amount of weight need for an object to travel far. First, the students will assemble a robot that can launch objects. Second, they will design a program in NXT MindStorm that will cause the robot to launch objects. Third, using Image 3 as a guide, students will setup their experiment for launching objects. Fourth, they will launch objects of different weights and record their distance. Fifth, they will change the angle of the launcher and see how far the same objects travel. Sixth, they will manipulate the length of the arm and see how far the object travels. Finally, students will analyze all these factors and figure out which manipulation makes the object travel farther.

Teachengineering.org | Complete Activity (pdf) | Worksheet (pdf)

**Calculate Gravitational Acceleration**

**Summary:** Students explore the natural phenomenon of gravity through the use of the LEGO Mindstorms kit and the included Data Logging software. First, students learn about the role of gravity in various phenomena such as gravity keeping a planet in orbit around the sun and free-falling objects. Students become familiar with Newton's universal law of gravitation and calculate the theoretical value for gravitational acceleration, g. Next, the students construct a simple robot design as the one illustrated in the LEGO Mindstorms manual. The students add on the robot arm attachment illustrated in the included attachment. Students actively participate in a free-fall activity using the LEGO Mindstorms software, LEGO light sensor, and Data Logging software. Students calculate an experimental value for the gravitational acceleration experienced by all objects on Earth to a reasonable approximation.

Complete Activity (pdf) | Worksheet (pdf)

**Get in Gear**

**Summary:** Students are introduced to the idea of gear ratios and how they are used in everyday life and in robotics. Students discover how gears work and how they can be used effectively in robot designs to increase speed or torque. Students quickly recognize that some tasks require a faster robot while others are more suited for slower, more powerful robots. They are introduced to torque and speed, the two traits of the robot affected by using gears. Once the students are introduced to the principles behind gear ratios, they are put to the test in two simple activities. One of the activities is better suited for a quicker robot while the other calls for a more powerful robot. A set of questions follow in the attached worksheet to ensure that the students understand the way gears work and the balance between torque and speed.

Teachengineering.org | Complete Activity (pdf) | Worksheet (pdf)

**Sensing Your Surroundings**

**Summary:**Students are presented with a variety of sensors and learn about their functions. In addition to identifying everyday sensors, students are introduced to the three components of a biosensor, which is a special type of sensor. Students compare sensors with various organs of the body and recognize similar behaviors. Throughout history, and into the foreseeable future, sensors are important for informing people of their surroundings and ultimately improving the quality of life. Students realize the importance of sensors and the valuable role they play in our daily lives.

Teachengineering.org | Complete Activity (pdf) | Worksheet (pdf) | Building Instructions (pdf)

**All Fat Is Not Created Equally!**

**Summary:** Students learn that fats found in the foods we eat are not all the same; they discover that physical properties of materials are related to their chemical structures. Provided with several samples of commonly used fats with different chemical properties (olive oil, vegetable oil, shortening, animal fat and butter), student groups build and use simple LEGO® MINDSTORMS® NXT robots with temperature and light sensors to determine the melting points of the fat samples. Because of their different chemical structures, these fats exhibit different physical properties, such as melting point and color. This activity uses the fact that fats are opaque when solid and translucent when liquid to determine the melting point of each sample upon being heated. Students heat the samples, and use the robot to determine when samples are melted. They analyze plots of their collected data to compare melting points of the oil samples to look for trends. Discrepancies are correlated to differences in the chemical structure and composition of the fats.

Teachengineering.org | Complete Activity (pdf)

**Bacteria are Everywhere!**

**Summary:** In this exercise, students will learn that bacteria can be found everywhere, including on the surface of our own hands. Students will study three different conditions and compare the growth of bacteria from these surfaces: (1) unwashed hand, (2) hand washed with soap and water, and (3) hand sanitized with antibacterial hand gel. The students will take swabs of their hands in these three different conditions and streak the swabs on Petri dishes containing agar gel which supports bacterial growth. After creating these three samples, over the period of one week the Petri dishes will show growth of several different kinds of bacteria, and the students will quantitatively compare the amount of bacteria growing from each test condition. Quantitative analysis of these samples will be done by taking photos of the Petri dishes at different time points and analyzing the images through imaging software. In addition to monitoring the quantity of bacteria from differ conditions, they will also be able to record the growth of bacteria over time, which is an excellent tool to study binary fission and the reproduction of unicellular organisms.

**Determining Concentration**

**Summary:** Students quantify the percent of light reflected from solutions containing varying concentrations of red dye using LEGO© MINDSTORMS© NXT bricks and light sensors. They begin by analyzing a set of standard solutions with known concentrations of food coloring, and plot data to graphically determine the relationship between percent reflected light and dye concentration. Then they identify dye concentrations for two unknown solution samples based on how much light they reflect. Students gain an understanding of light scattering applications and how to determine properties of unknown samples based on a set of standard samples.

**Viscosity: The Flow of Milk**

**Summary:** Students study the physical properties of different fluids and investigate the relationship between the viscosities of a liquid and how fast the liquid flows through a confined area. Students work in groups to conduct a brief experiment in which they will quantify the flow rate to understand how it relates to a fluid's viscosity and ultimately chemical composition. Students explore these properties in milk and cream, which are commonly found fluids whose properties (even taste!) differ based on their fat content. They receive control samples as well as unknown samples that they will have to identify based on how fast they flow. To identify the unknowns, students must understand the concept of viscosity. For example, heavy cream will flow at a slower rate than skim milk. Ultimately, students gain an understanding of the concept of viscosity and its effect on flow rate.

**Force Analysis of a Moving Vehicle**

**Summary: **This LEGO Mindstorms-based activity is geared for Regents or AP Physics students. In this activity students practice to measure and analyze various forces that act on the vehicle that is moving at a constant speed on the frictional surface. During this activity students identify, measure and calculate forces that act on a moving object, i.e., weight, normal force, force of friction, force generated by the motor, tension in the string. Students use scales to measure the weight and the pulling force of the car and calculate the other forces using formulae.

Complete Activity (pdf) | Worksheet (pdf) | Pre Evaluation (pdf) | Post Evaluation (pdf)

**Means, Modes and Medians**

**Summary: **During this activity students will collect the data of the spring deflection using LEGO equipment. They will use their measurements to calculate the mean, median, mode, range, percent difference and learn how to represent their data in excel.

Teaachengineering.org | Complete Activity (pdf) | Worksheet (pdf) | Pre Evaluation (pdf) | Post Evaluation (pdf)

**Measuring Distance With Sound Waves**

**Summary: **Through this activity, students learn about sound waves and utilize them as a tool to measure distance between objects. The activity explores how engineers incorporate ultrasound waves to design devices that are used to make sonograms and sonar equipment. Students learn about properties, sources and applications of three types of sound waves, known as the infra-, audible- and ultra-sound frequency ranges. Students use ultrasound waves to measure distances and understand how the sensor is engineered.

**How to Pull Something Heavy**

**Summary: **Students measure and analyze forces that act on vehicles pulling heavy objects while moving at a constant speed on a frictional surface. They study how the cars interact with their environments through forces, and discover which parameters in the design of the cars and environments could be altered to improve vehicles' pulling power. This LEGO® MINDSTORMS® based activity is geared towards, but not limited to, physics students.

**Building a Visible Light Spectrophotometer**

**Summary: **This activity introduces students to visible light spectroscopy and chemical kinetics. In spectroscopy light is used to characterize a liquid solution or suspension. The idea is that the intensity of light that enters a liquid is lowered as the light energy excites species, thus the lights is emitted at a lower intensity. As shown in Figure 1, the idea of the anatomy of a sensor can be used to explain the operation of a visible light spectrophotometer. The following mnemonic is used: Sensors = Stimulus + Transducer + Signal (STS). Here it is clear that, a sensor is a device that detects an external stimulus, and changes that stimulus to a detectable signal, by means of a transducer. For our device, light intensity (the stimulus) is detected, the semi-conductor material responds by becoming a conductor of electricity (transducer), and the resulting current flow is the sensor response (signal). The end goal is to design a crude visible light spectrophotometer (vis-spec) or more correctly a colorimeter using the NXT brick, and two NXT light sensors. One sensor is used in the light active mode as a visible polychromatic light source (LED), and the other is used in the light inactive mode as a detector (via a phototransistor). This process is repeated for a reference solution, and a ratio of intensities is calculated, that relates directly to amount of substance in the liquid.

Complete Activity (pdf) | Worksheet (pdf)

**What is a Photoresistor?**

**Summary: **This activity aims to introduce to students a photoresistor, which is often used in a light dependent voltage divider circuit. A photoresistor is part of a larger family of devices or sensors known as photodetectors. A photodetector's resistance to electrical current changes when it is exposed to light. Photodetectors are commonly used as light sensitive switches; for examples common streetlights that turn on at dusk employ photoresistor circuits. As depicted in Figure 1, the basic anatomy of a sensor can be used to explain the operation of a photoresistor. The following mnemonic is used: Sensors = Stimulus + Transducer + Signal (STS). That is, a sensor is a device that detects an external stimulus, and it changes that stimulus to a detectable signal, by means of a transducer. For our photoresistor, when light (the stimulus) is detected, the semiconductor material responds by becoming a conductor of electricity (transducer), and the resulting current flow is the sensor response (signal). A photoresistor, which consists of cadmium sulfide, responds to visible light similarly to the human eye, and it can be thought of as an electronic analog of the human eye.

**Exploring Images**

**Summary: **Students learn about different ways in which images can be manipulated using computer programs. Using the Processing programming environment, students modify example programs to produce different effects on given images: brightening or darkening an image, cropping sections from images, image rotation, and zooming.

**Image Scanner!**

**Summary: **In this activity, students use the Lego Mindstorms Education kit to build a simple digital image scanner consisting of an NXT Mindstorms intelligent brick and an NXT light sensor. Students create a simple image of their choosing on supplied square ruled paper, and use the scanner to read in their images into a file. Using the Processing programming environment, students process the scanned file and display it on a computer screen.

Complete Activity (pdf) | Worksheet (pdf)

**Mouse Trap Racer in the Computer Age!**

**Summary: **Students design, build, and evaluate a spring-powered mouse trap racer. For evaluation, teams equip their racers with an intelligent brick from a Lego Mindstorms Education kit and a Hitechnic acceleration sensor. Acceleration data collected during launch is used to compute velocity and displacement versus time graphs. In the process, students learn about the importance of fitting mathematical models to measurements of physical quantities, reinforce their knowledge of Newtonian mechanics, deal with design compromises, learn about data acquisition and logging, and carry out collaborative assessment of results from all participating teams.

Teachengineering.org | Complete Activity (pdf) | Analysis Worksheet (pdf) | Statistics Worksheet (pdf)

**Traffic Lights**

**Summary: **Students learn about traffic lights and their importance in maintaining public safety and order. Using the Basic Stamp 2 (BS2) microcontroller, students work in teams on the engineering task of building a traffic light with specified behavior. In the process, students learn about light emitting diodes (LEDs), and how their use can save energy. As programmers, students learn two simple commands used in programming the BS2 microcontroller, and a program control concept called a loop.

Teachengineering.org | Complete Activity (pdf) | Activity Solution (pdf)

**"Zeros", "Ones", and the Morse Code**

**Summary: **Students will learn about the binary number system computers use to store data, in which numbers are represented as sequences of zeros and ones. Using the Basic Stamp 2 (BS2) microcontroller, students will experiment with Morse code - one of the oldest communication methods still in use today. In the process, students learn about how only two signaling elements - the "dit" and the "dah", or 0 and 1, can be used to encode arbitrarily complex messages. The activity introduces a number of useful commands used to program the BS2 microcontroller, as well as concepts of computer memory, data types, and data transfer for input and output.

**Fence That Farmland!**

**Summary: **Students develop and solidify their understanding of the concept of "perimeter" as they engage in a portion of the civil engineering task of land surveying. Specifically, they measure and calculate the perimeter of a fenced in area of "farmland," and see that this length is equivalent to the minimum required length of a fence to enclose it. Doing this for variously shaped areas confirms that the perimeter is the minimal length of fence required to enclose those shapes. Then students use the technology of a LEGO® MINDSTORMS® NXT robot to automate this task. After measuring the perimeter (and thus required fence length) of the "farmland," students see the NXT robot travel around this length, just as a surveyor might travel around an area during the course of surveying land or measuring for fence materials. While practicing their problem solving and measurement skills, students learn and reinforce their scientific and geometric vocabulary.

**How Cold Can You Go?**

**Summary: **Students will use a mechatronic temperature sensor to learn about the lower temperature limit at which liquid water can exist—specifically, that even if placed in contact with a material much colder than 32 degrees Fahrenheit, liquid water will not get colder than 32 degrees Fahrenheit.

Teachengineering.org | Complete Activity (pdf)

**Parallel & Intersecting Lines—A Collision Course?**

**Summary: **Students will solidify their understanding of different types of lines, as well as line features, specifically: parallel lines, non-parallel lines, and points of line intersection. This understanding will be developed through application of these concepts to LEGO MINDSTORMS robots, and practice identifying examples of each concept in this context. Students will identify whether or not different robot “tracks” laid down by the instructor are parallel or non-parallel, and will observe the consequences of their understanding by allowing two robots to travel simultaneously along these tracks. Robots that are on intersecting courses will face imminent collision, while robots on parallel courses will travel in safety. This lesson will help prepare students for the geometry portion of the New York State education standards in mathematics, while simultaneously entertaining students through hands-on interaction with LEGO MINDSTORMS NXT robots.

Teachengineering.org | Complete Activity (pdf) | Pre Evaluation (pdf) | Post Evaluation (pdf)

**Robot Wheels!**

**Summary:** Students will solidify their understanding of the geometry term ?perimeter? through application of the concept to LEGO Mindstorms NXT robotics programming. Students will measure the perimeter of LEGO Mindstorms NXT robot wheels in order to determine how far the robot can travel during one rotation of an NXT motor. Students will also enhance their metric system measurement skills by having to precisely record the length of a wheel’s perimeter in centimeters, and fractions of centimeters. The importance of fractions of centimeters will be emphasized through this measurement process.

Teachengineering.org | Complete Activity (pdf) | Pre Evaluation (pdf) | Post Evaluation (pdf)

**Save the Stuffed Animal! Push & Pull**

**Summary:** Students develop an understanding of the concepts of "push" and "pull" as they "save" stuffed animals from danger using LEGO® MINDSTORMS® NXT robots. After learning more about the concepts through a robot demonstration, students explore the concepts themselves in the context of saving stuffed animala from the table edges. They choose to either push or pull the animal to safety, depending on the orientation of the robot and toy. They see the consequences of their choices, learning the importance of understanding these force concepts and the differences between them.

**Water Mix-ology!**

**Summary:** Students will combine the power of their own five senses, as well as a mechtronic temperature sensor, to investigate the properties of water, and how the properties of water change upon addition of various materials. Students will also gain greater experience with use of the scientific method by making predictions about how different materials will affect the properties of water, and comparing these predictions to the changes actually observed.

**Water Un-Mix-ology & Purification!**

**Summary:** Students will learn the principals behind how water filtration systems can change visibly dirty water to visibly clean water. Students will accomplish this by two means—a fast, percolation based filter modeled on the filtration which occurs in soils, as well as a slower, evaporation based filtration model modeled on the filtration which occurs for rainwater. Students will gain greater experience with use of the scientific method by making predictions about effective their filters will be at cleaning water, and comparing these predictions to the changes actually observed. Changes in the water’s cleanliness will be measured both visibly, and with a mechatronic light sensor.

**The Fibonacci Sequence & Robots**

**Summary: **Using the LEGO NXT Robotics kit, students learn how to build and program a robot. Students are assigned tasks, consisting of group leader, chassis builder, arm builder, chief programmer, and Fibonacci verifier. By building a robot that moves based on the Fibonacci sequence of numbers, we can to visually see how quickly the numbers in the sequence grow. Programming the robot to move according to these numbers will allow us to break down the sequence into simple algebraic equations, so that a computer can understand the Fibonacci sequence.

Teachengineering.org | Complete Activity (pdf) | Worksheet (pdf)

**Measuring Pressure**

**Summary:** Students learn first-hand the relationship between force, area, and pressure. The students use a force sensor, built from a Lego NXT kit, to measure the force required to break through a napkin. The end of the force sensor has an interchangeable tip, allowing for different sized areas to apply the pressure across. Measuring the force, and knowing the area, the students compute the pressure.

**How Far Does the Robot Go?**

**Summary:** In this activity, the students practice their multiplication skills using a robot with wheels built from Legos. First, the students are encouraged to think of ways to determine the distance travelled by the robot without physically measuring the distance from the starting location to the final location. After the students are allowed to brainstorm for some time, they try to determine the distance by measuring the circumference of the wheels, and multiplying the circumference of the wheel by the number of revolutions that the robot was programmed to do. Once they do this, they can physically measure the distance travelled and compare it to the one they obtained by multiplication. They get to practice multiplication and develop measuring skills, as well as are encouraged to come up with a creative solution to the problem.

Teachengineering.org | Worksheet (pdf)

**Which Cools Faster?**

**Summary:** Students observe and record the cooling of water in two conditions – in water and in air. They construct a very simple heat exchanger using cups, with water and air being the heat transfer fluids. They learn that water has better heat transferring properties than air.

**Sensing Your Surroundings**

**Summary: **Students consider human senses and the many everyday human-made sensors so common in their lives. They learn about the three components of biosensors—a special type of sensor—and their functions and importance. With this understanding, students identify various organs in the human body that behave as sensors, such as the pancreas. Using LEGO® MINDSTORMS® NXT robots, provided rbt robot programs and LEGO sensors (light, ultrasonic, sound, touch), students gain first-hand experience with sensors and come to see how engineer-designed sensors play important roles in our daily lives, informing people of their surroundings and ultimately improving our quality of life.

**Angular Velocity: Sweet Wheels**

**Summary:** Students analyze the relationship between wheel radius, linear velocity and angular velocity by using LEGO® MINDSTORMS® EV3 robots. Given various robots with different wheel sizes and fixed motor speeds, they predict which has the fastest linear velocity. Then student teams collect and graph data to analyze the relationships between wheel size and linear velocity and find the angular velocity of the robot given its motor speed. Students explore other ways to increase linear velocity by changing motor speeds, and discuss and evaluate the optimal wheel size and desired linear velocities on vehicles.

**Biomimicry: Echolocation in Robotics**

**Summary:** Students use ultrasonic sensors and LEGO© MINDSTORMS© NXT robots to emulate how bats use echolocation to detect obstacles. They measure the robot's reaction times as it senses objects at two distances and with different sensor threshold values, and again after making adjustments to optimize its effectiveness. Like engineers, they gather and graph data to analyze a given design (from the tutorial) and make modifications to the sensor placement and/or threshold values in order to improve the robot's performance (iterative design). Students see how problem solving with biomimicry design is directly related to understanding and making observations of nature.

** Haptics: Touch Command**

**Summary:** Students experience haptic (the sense of touch) feedback by using LEGO® MINDSTORMS® NXT robots and touch sensors to emulate touch feedback recognition. With four touch sensors connected to LEGO NXTs, they design sensor attachments that feel physically distinguishable from each another. Then students answer questions and communicate their answers to the NXT by pressing the touch sensor that is associated with the right multiple-choice answer letter. Haptics becomes essential when students must use the NXT sensors to answer the next set of questions without the aid of their vision. This challenges them to rely solely on the tactile feeling of each unique touch sensor attachment that they created in order to choose the correct peripheral slot. Students also learn about real-world applications of haptics technology.

**Foucault Pendulum**

**Summary:** Students learn about the Foucault pendulum—an engineering tool used to demonstrate and measure the Earth's rotation. Student groups create small experimental versions, each comprised of a pendulum and a video camera mounted on a rotating platform actuated by a LEGO® MINDSTORMS® NXT motor. When the platform is fixed, the pendulum motion forms a line, as observed in the recorded video. When the rotating, the pendulum's motion is observed as a set of spirals with a common center. Observing the patterns that the pendulum bob makes when the platform is rotating provides insight as to how a full-size Foucault pendulum operates. It helps students understand some of the physical phenomena induced by the Earth's rotation, as well as the tricky concept of how the perception of movement varies, depending on one's frame of reference.

**Measuring Light Pollution**

**Summary:** Students are introduced to the concept of light pollution by investigating the nature, sources and levels of light in their classroom environment. They learn about the adverse effects of artificial light and the resulting consequences on humans, animals and plants: sky glow, direct glare, light trespass, animal disorientation and energy waste. Student teams build light meters using light sensors mounted to LEGO® MINDSTORMS® NXT intelligent bricks and then record and graph the light intensity emitted in various classroom lighting situations. They are introduced to the engineering concepts of sensors, lux or light meter, and lumen and lux (lx) illuminance units. Through this activity, students also learn how to better use light and save energy as well as some of the technologies designed by engineers to reduce light pollution and energy waste.

**Measuring Noise Pollution**

**Summary:** Through investigating the nature, sources and level of noise produced in their environment, students are introduced to the concept of noise pollution. They learn about the undesirable and disturbing effects of noise and the resulting consequences on people's health, as well as on the health of the environment. They use a sound level meter that consists of a sound sensor attached to the LEGO® NXT Intelligent Brick to record the noise level emitted by various sources. They are introduced to engineering concepts such as sensors, decibel (dB) measurements, and sound pressure used to measure the noise level. Students are introduced to impairments resulting from noise exposure such as speech interference, hearing loss, sleep disruption and reduced productivity. They identify potential noise pollution sources, and based on recorded data, they classify these sources into levels of annoyance. Students also explore the technologies designed by engineers to protect against the harmful effects of noise pollution.

**Ultrasound Imaging**

**Summary:** Students learn about ultrasound and how it can be used to determine the shapes and contours of unseen objects. Using a one-dimensional ultrasound imaging device (either prepared by the teacher or put together by the students) that incorporates a LEGO® MINDSTORMS® NXT intelligent brick and ultrasonic sensor, they measure and plot the shape of an unknown object covered by a box. Looking at the plotted data, they make inferences about the shape of the object and guess what it is. Students also learn how engineers use high-frequency waves in the design of medical imaging devices, the analysis of materials and oceanographic exploration. Pre/post quizzes, a worksheet and a LEGO rbt program are provided.

**Decimals, Fractions & Percentages**

**Summary:** Students learn about and practice converting between fractions, decimals and percentages. Using a LEGO® MINDSTORMS® NXT robot and a touch sensor, each group inputs a fraction of its choosing. Team members convert this same fraction into a decimal, and then a percentage via hand calculations, and double check their work using the NXT robot. Then they observe the robot moving forward and record that distance. Students learn that the distance moved is a fraction of the full distance, based on the fraction that they input, so if they input ½, the robot moves half of the original distance. From this, students work backwards to compute the full distance. Groups then compete in a game in which they are challenged to move the robot as close as possible to a target distance by inputting a fraction into the NXT bot.

**The Claw**

**Summary: **In this lesson, students will lift multiple objects using a crane incorporating different gear ratios. A fun spin on the project could be basing it off the popular movie trilogy Toy Story (hence, the name of the lesson). Students will be engaged in learning how to operate a toy mechanical crane, while learning about the concept of gear ratios and power. They will be able to experiment picking up objects of different weights to witness how much power they must apply to the system in order to combat the force of gravity.

Teachengineering.org | Complete Activity (pdf)

**Projectile Motion**

**Summary:** This activity exposes students to the concept of projectile motion. Students are often familiar with projectile motion from life experiences, such as playing sports like basketball or baseball, but they don't always understand the physics involved. This activity is designed to show students that robotics can be used to build a projectile thrower and measure motion using sensors. Students compute distances and velocities using simple kinematic equations and confirm their results through measurements by hand. To apply this concept, students calculate the necessary speed of an object to reach a certain distance. The scenario is based on a group of hikers stranded at the bottom of a cliff. They need food, but the rescuers cannot deliver it themselves. They must devise a way to get the food to the hikers.

**Tug of War Battle Bots**

**Summary: **Students are introduced to the concepts of torque, power, friction and gear ratios. Teams modify two robotic LEGO vehicles by changing their gear ratios, wheel sizes, weight and engine power, while staying within a limit of points to spend on modifications. The robots face each other on a track with a string attaching one to the other. The winning robot, the one with the best adjustments, pulls the other across the line.

**What’s In a Name?**

**Summary: **This programming activity teaches students the different kinds of turns that a multi-wheel robot can perform. Each group is asked to program their robot to write the name of their team on a piece of paper. The activity emphasizes the difference in path taken along with the required programming for each kind of turn. All programming is done in RobotC language used in Lego Mindstorms NXTs. As a method of explanation, students also encounter geometry concepts used for wheel radii.

Complete Activity (pdf) | Pre Evaluation (pdf) | Post Evaluation (pdf)

**Ding! Going Up? Elevators and Engineering**

**Summary:** Students create model elevator carriages and calibrate them, similar to the work of design and quality control engineers. Students use measurements from rotary encoders to recreate the task of calibrating elevators for a high-rise building. They translate the rotations from an encoder to correspond to the heights of different floors in a hypothetical multi-story building. Students also determine the accuracy of their model elevators in getting passengers to their correct destinations.

**Gears: Lift It Up!**

**Summary:** A gear is a simple machine that is very useful to increase the speed or torque of a wheel. In this activity, students learn about the trade-off between speed and torque when designing gear ratios. The activity setup includes a LEGO® MINDSTORMS® pulley system with two independent gear sets and motors that spin two pulleys. Each pulley has weights attached by string. In a teacher demonstration, the effect of adding increasing amounts of weight to the pulley systems with different gear ratios is observed as the system's ability to lift the weights is tested. Then student teams are challenged to design a gear set that will lift a given load as quickly as possible. They test and refine their designs to find the ideal gear ratio, one that provides enough torque to lift the weight while still achieving the fastest speed possible.

**Rotary Encoders & Human-Computer Interaction**

**Summary:** Students learn about rotary encoders and discover how they operate through hands-on experimentation. Rotary encoders are applied in tools to determine angle measurements and for translations of angular motion. One common rotary encoder application is in a computer's ball-type mouse—the ball itself is a type of rotary encoder. In this activity, students experiment with two rotary encoders, including one from a computer mouse and one created using a LEGO® MINDSTORMS® NXT kit. They collect data to define and graph the relationship between the motion of the rotary encoder and its output.

**About Accuracy and Approximation**

**Summary:** During this activity students will be learning about the concept of accuracy as it pertains to robotics. Students will be gaining insight into experimental accuracy and knowing how and when to estimate values that they measure. Awareness of sources of error stemming from the robotic setup in conjunction with number rounding is explored.

**A LEGO® Introduction to Graphing**

**Summary:** Students use a LEGO® ball shooter to demonstrate and analyze the motion of a projectile through use of a line graph. This activity involves using a method of data organization and trend observation with respect to dynamic experimentation with a complex machine. Also, the topic of line data graphing is covered. The main objective is to introduce students graphs in terms of observing and demonstrating their usefulness in scientific and engineering inquiries. During the activity, students point out trends in the data and the overall relationship that can be deduced from plotting data derived from test trials with the ball shooter.

**The Science of Spring Force**

**Summary:** During this activity, students use data acquisition equipment to learn about force and displacement in regard to simple or complex machines. In the engineering world, materials and/or systems are tested by applying forces to the material or system and measuring the displacements that result. The relationship between the force applied on a material, and its resulting displacement, is a distinct property of the material, which is measured in order to evaluate the material for proper use in structures and machines.

**Solving with Seesaws**

**Summary:** Students during this activity are using a simple machine to demonstrate an analogous visualization of solving two or three-step equations in mathematics. Students in the classroom will not only solve two-step equations on a provided worksheet, but will also solve the equations using the seesaw balance. The use of sensor equipment for proper position monitoring is used to aid students in balancing the structure, as well as balancing the equation as they solve it on paper.

**Test-A-Beam**

**Summary:** Students during this activity are learning about the measurement and mathematics behind simple structures that are seen in everyday life, such as a beam. Geometry, along with other factors and characteristics, can affect the how and the why certain structures are used. Students will be able to investigate this for themselves, as they will perform an experiment on different types of beams. Students will measure different types of beams for their cross-sectional area values, and compare them to how much they bend as a load is placed on each beam. By doing this, students will be able to investigate the ideal geometry and material for a load bearing beam.

**Aircraft Propeller Revolutions per Minute**

**Summary:** Each group of students will construct a test rig for measuring the RPM (Revolutions per Minute) of a model aircraft (scaled) propeller. The test rig consists of a LEGO NXT Brick, NXT Motor and NXT Light sensor. The propeller is mounted on the motor and the students will measure the time elapsed between propeller blades passing over the light sensor. Two or three bladed propellers can be used.

**Pendulum Pandemonium**

**Summary:** Each group of students will construct a LEGO Mindstorm NXT set-up that includes a pendulum and a light sensor. The light sensor will detect time instances when the pendulum's bob passes through a certain point as dips on a plot of measured light intensity. From these plots, students will measure the period of the pendulum for different lengths of the pendulum rod. Next, they will compare the experimentally determined values of the period to values calculated using a well-know formula. Finally, they will change the weight of the bob connected to the pendulum string and repeat the experiment to verify that the period of the pendulum is not affected by changes in the bob's weight. A discussion on the practical applications of pendulum technology and its history should be included as part of the post-activity assessment.

**Boom Construction**

**Summary:** Student teams design their own booms (bridges) and engage in a friendly competition with other teams to test their designs. Each team strives to design a boom that is light, can hold a certain amount of weight, and is affordable to build. Teams are also assessed on how close their design estimations are to the final weight and cost of their boom "construction." This activity teaches students how to simplify the math behind the risk and estimation process that takes place at every engineering firm prior to the bidding phase—when an engineering firm calculates how much money it will take to build the project and then "bids" against other competitors.

**Linear Equations Game**

**Summary:** Students groups act as aerospace engineering teams competing to create linear equations to guide space shuttles safely through obstacles generated by a modeling game in level-based rounds. Each round provides a different configuration of the obstacle, which consists of two "gates." The obstacles are presented as asteroids or comets, and the linear equations as inputs into autopilot on board the shuttle. The winning group is the one that first generates the successful equations for all levels. The game is created via the programming software MATLAB, available as a free 30-day trial. The activity helps students make the connection between graphs and the real world. In this activity, they can see the path of a space shuttle modeled by a linear equation, as if they were looking from above.

**Timing a Speedbot!**

**Summary:** Students work in groups using a timer or stopwatch to measure the speed of an NXT robot. The robot can be started and stopped by using a touch sensor and it is programmed to display the distance it has traveled in centimeters after it stops. Using the gathered data, students complete a worksheet to determine the mean speed of an NXT robot at a given motor power.

**Building Our Bridge to Fun!Building Our Bridge to Fun!**

**Summary:** Students identify different bridge designs and construction materials used in modern day engineering. They work in construction teams to create paper bridges and spaghetti bridges based on existing bridge designs. Students progressively realize the importance of the structural elements in each bridge. They also measure vertical displacements under the center of the spaghetti bridge span when a load is applied. Vertical deflection is measured using a LEGO® MINDSTORMS® NXT intelligent brick and ultrasonic sensor. As they work, students experience tension and compression forces acting on structural elements of the two bridge prototypes. In conclusion, students discuss the material properties of paper and spaghetti and compare bridge designs with performance outcomes.

**Erosion in Rivers**

**Summary:** Students learn about water erosion through an experimental process in which small-scale buildings are placed along a simulated riverbank to experience a range of flooding conditions. They learn how soil conditions are important to the stability or failure of civil engineering projects and how a river's turns and bends (curvature, sinuosity) make a difference in the likelihood of erosion. They make model buildings either with a 3D printer or with LEGO® pieces and then see how their designs and riverbank placements are impacted by slow (laminar) and fast (turbulent) water flow over the soil. Students make predictions, observations and conclusions about the stability of their model houses, and develop ideas for how to mitigate damage in civil engineering projects.

**How Fast Does Water Travel through Soils?**

**Summary:** Underground water, which is the water located under the ground surface, is of vital importance for human beings since it is a natural resource for drinking and irrigation. Underground water also plays an important role in civil engineering. Water flow within an aquifer, land slope, and earth dam is of interest of engineers to develop accurate designs and optimal constructions. To study water flow inside soil mass the coefficient of permeability, k, should be known.

In soils, k is the measurement of water ability to flow through them. In other words is the speed of water flow inside soils such as gravel, sand, silt, clay, or a mix of them. This activity is prepared to introduce the concept of soil permeability as one of the key parameters to study seepage or the steady state flow of water. Students will have the opportunity of measuring permeability of different types of soils, compare results, and conclude the importance of size, voids, and density in permeability response.

Teachengineering.org | Complete Activity (pdf) | Pre Evaluation (pdf) | Post Evaluation (pdf)

**The Stress That You Apply**

**Summary: **Students learn about contact stress and its applications in engineering. They are introduced to the concept of heavy loads, such as buildings, elephants, people and traffic, and learn how those heavy loads apply contact stress. Through the analysis of their own footprints, students determine their contact stress.

Teachengineering.org | Worksheet (pdf)

**A Chance at Monte Carlo**

**Summary:** At its core, the LEGO® MINDSTORMS® NXT product provides a programmable microprocessor. Students use the NXT processor to simulate an experiment involving thousands of uniformly random points placed within a unit square. Using the underlying geometry of the experimental model, as well as the geometric definition of the constant π (pi), students form an empirical ratio of areas to estimate a numerical value of π. Although typically used for numerical integration of irregular shapes, in this activity, students use a Monte Carlo simulation to estimate a common but rather complex analytical form—the numerical value of the most famous irrational number, π.

**Panoptes and the Bionic Eye**

**Summary:** Vision is the primary sense of many animals and much is known about how vision is processed in the mammalian nervous system. One distinct property of the primary visual cortex is a highly organized pattern of sensitivity to location and orientation of objects in the visual field. But how did we learn this? An important tool is the ability to design experiments to map out the structure and response of a system such as vision. In this activity, students learn about the visual system and then conduct a model experiment to map the visual field response of a Panoptes robot. (In Greek mythology, Argus Panoptes was the "all-seeing" watchman giant with 100 eyes.) A simple activity modification enables a true black box experiment, in which students do not directly observe how the visual system is configured, and must match the input to the output in order to reconstruct the unseen system inside the box.

**Materials Properties Make a Difference**

**Summary:** Students investigate the materials properties—such as acoustical absorptivity, light reflectivity, thermal conductivity, hardness, and water resistance—of various materials. They use sound, light and temperature sensors to collect data on various materials. They practice making design decisions about what materials would be best to use for specific purposes and projects, such as designing houses in certain environments to meet client requirements. After testing, they use the provided/tested materials to design and build model houses to meet client specifications.

**Robotic Perimeter**

**Summary:** In this activity students learn how to find the perimeter of a shape. Using a ruler, students measure model rooms made of construction paper. In addition they learn how they can use other tools such as a robot to help them take measurements, the ways in which this may be advantageous or disadvantageous, and discuss real world applications. Using a robot, built from a Lego NXT kit, that has been programmed to move alongside a wall and output the length of that wall, students note down the measurements found and compare their findings for the perimeter found earlier. In both cases students also sketch a map of their area that is to scale, and labeled with the lengths found.

Teachengineering.org | Complete Activity (pdf)

**Acceleration Due to Gravity**

**Summary:** Using the Lego Mindstorms kit, students will construct an experiment where the time to travel a specified distance by a free falling body is measured. Students will use the touch sensor, rotational sensor, and the NXT brick, to measure the time of flight for the falling object, at different release heights. After the object is released from its holder and travels a specified distance, a touch sensor is triggered and time of object's descent from release to impact at touch sensor is recorded and displayed on the screen of the NXT. Students will calculate the velocity of the falling object at each point of release, and construct a graph of velocity versus time. A best fit line will then be applied to this graph, of which the slope will be obtained and compared to the standard value of g.

Complete Activity (pdf) | Worksheet (pdf) | Pre Evaluation (pdf) | Post Evaluation (pdf)

**Gear Down for Speed**

**Summary:** Using the Lego Mindstorms kit, a simple robot will be constructed and used to explore the relationship between gears, speed and torque. The motion of the robot is governed by attaching wheels to motors, such that the robot is permitted to move in all directions. Students will measure the linear distance traveled by the robot in a specified time, calculate its speed and gauge impact of adding gears to the speed of the robot. Furthermore, students will be introduced to a mathematical relationship between the speed and gear ratios and use it to predict the speed of the robot.

Complete Activity (pdf) | Worksheet (pdf)

**Making an Ultra Violet (UV) Light Detector**

**Summary:** Students build a simple sensor for detecting ultra violet (UV) light. Students use specialized beads that are sensitive to UV light and various materials that facilitate the immobilization of the sensor to different objects, including themselves. Students show that although UV light cannot be seen by the human eye, it is still present in sunlight, and can be detected using this sensor. Students also test the effectiveness of various materials at blocking UV light, such as sunscreen and glass.

**Measuring g for Gravity**

**Summary: **Using the LEGO® MINDSTORMS® NXT kit, students construct experiments to measure the time it takes a free falling body to travel a specified distance. Students use the touch sensor, rotational sensor, and the NXT brick to measure the time of flight for the falling object at different release heights. After the object is released from its holder and travels a specified distance, a touch sensor is triggered and time of object's descent from release to impact at touch sensor is recorded and displayed on the screen of the NXT. Students calculate the average velocity of the falling object from each point of release, and construct a graph of average velocity versus time. They also create a best fit line for the graph using spreadsheet software. Students use the slope of the best fit line to determine their experimental g value and compare this to the standard value of g.

**What's the Conductivity of Gatorade?**

**Summary:** Using a conductivity meter constructed from the Basic stamp microcontroller, Parallax Board of Education and typical circuit elements, students measure the conductivity of various salt and water solutions. The conductivity of the salt solution is indicted by the number of LEDs (light emitting diodes) that are illuminated on the meter. Students will construct a calibration curve using known amounts of table salt dissolved in water, and their corresponding conductivity readings. This calibration curve will then be used to estimate the total equivalent amount of salt contained in Gatorade (or an unknown salt solution).

Teachengineering.org | Complete Activity (pdf) | Worksheet (pdf) | Building Instructions (pdf)

**The Car with a Lot of Potential**

**Summary:** Working in teams of three, students perform quantitative observational experiments on the motion of LEGO vehicles that are powered by the stored potential energy of a rubber band. The students will have the opportunity to experiment with different vehicle modifications (e.g. wheel type, payload, and lubrication) and monitor the effects on vehicle performance. The main point of the lesson, however, is to communicate to the students that through the manipulation of mechanics, a rubber band can be used in a rather non-traditional configuration to power a vehicle. In addition, this lesson reinforces the idea that elastic energy can be stored as potential energy.

Teachengineering.org | Complete Activity (pdf) | Building Instructions (pdf)

**The Power of Mechanical Advantage**

**Summary: **Students learn about the mechanical advantage that is offered by gears in an interactive and game-like manner. By virtue of the activity’s mechatronic presentation, the students learn to study a mechanical system not as a static image, but rather as a dynamic system that is under their control. The system that is presented is that of two motorized racing cars, which is built using the LEGO Mindstorms robotics platform. The variable that is altered between the two systems is their gear trains; one is geared up for speed and the other is geared down for torque. Students are charged with practicing data collection and data analysis to reinforce particular aspects/effects of mechanical advantage.

Teachengineering.org | Complete Activity (pdf) | Pre Evaluation (pdf) | Post Evaluation (pdf)

**Wide World of Gears**

**Summary:** In an interactive and game-like manner, students learn about the mechanical advantage that is offered by gears. By virtue of the activity's mechatronics presentation, students learn to study a mechanical system as a dynamic system under their control as opposed to a static image. The system presented is of two motorized racing cars built using the LEGO® MINDSTORMS® robotics platform. The altered variable between the two systems is the gear train; one is geared up for speed and the other is geared down for torque. Students collect and analyze data to reinforce particular aspects and effects of mechanical advantage.

**A Zipliner’s Delight**

**Summary:** Students learn about potential energy, as expressed as the height of an object along a linear on-dimensional zipline track. A robot, designed to traverse the track, converting stored potential energy into kinetic energy, also is capable of monitoring the instantaneous speed of the robot using various sensors. Thus, students are able to quantify and compare the starting potential energy (height) of a robot and the conversion thereof into kinetic energy (linear displacement). The system that is presented is that of a single robot, which is built using the LEGO Mindstorms robotics platform and installed with Lejos 0.9 firmware.