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.

Students discover the mathematical constant phi, the golden ratio, through hands-on activities. They measure dimensions of "natural objects"—a star, a nautilus shell and human hand bones—and calculate ratios of the measured values, which are close to phi. Then students learn a basic definition of a mathematical sequence, specifically the Fibonacci sequence. By taking ratios of successive terms of the sequence, they find numbers close to phi. They solve a squares puzzle that creates an approximate Fibonacci spiral. Finally, the instructor demonstrates the rule of the Fibonacci sequence via a LEGO® MINDSTORMS® NXT robot equipped with a pen. The robot (already created as part of the companion activity, The Fibonacci Sequence & Robots) draws a Fibonacci spiral that is similar to the nautilus shape.

Students' understanding of how robotic ultrasonic sensors work is reinforced in a design challenge involving LEGO MINDSTORMS(TM) NXT robots and ultrasonic sensors. Student groups program their robots to move freely without bumping into obstacles (toy LEGO people). They practice and learn programming skills and logic design in parallel. They see how robots take input from ultrasonic sensors and use it to make decisions to move, resulting in behavior similar to the human sense of sight but through the use of sound sensors, more like echolocation. Students design-test-redesign-retest to achieve successful programs. A PowerPoint® presentation and pre/post quizzes are provided.

This lesson introduces and describes the main types of erosion (i.e., chemical, water, wind, glacier and temperature). Students learn examples of each type of erosion and discuss how erosion changes the surface of the Earth. Students also learn why engineers need to be aware of the different types of erosion in order to protect structures and landmarks from the damaging effects erosion can cause. Figure 1 is an excellent illustration of water erosion.

Students follow the steps of the engineering design process (EDP) while learning about assistive devices and biomedical engineering. They first go through a design-build-test activity to learn the steps of the cyclical engineering design process. Then, during the three main activities (7 x 55 minutes each) student teams are given a fictional client statement and follow the EDP steps to design products an off-road wheelchair, a portable wheelchair ramp, and an automatic floor sweeper computer program. Students brainstorm ideas, identify suitable materials and demonstrate different methods of representing solutions to their design problems scale drawings or programming descriptions, and simple models or classroom prototypes.

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(TM) 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.

Using the LEGO® NXT robotics kit, students construct and program robots to illustrate and explore the Fibonacci sequence. Within teams, students are assigned roles: group leader, chassis builder, arm builder, chief programmer, and Fibonacci verifier. By designing a robot that moves based on the Fibonacci sequence of numbers, they can better visualize how quickly the numbers in the sequence grow. To program the robot to move according to these numbers, students break down the sequence into simple algebraic equations so that the computer can understand the Fibonacci sequence.

Students' understanding of how robotic light sensors work is reinforced in a design challenge involving LEGO MINDSTORMS(TM) NXT robots and light sensors. Working in pairs, students program LEGO robots to follow a flashlight as its light beam moves around. Students practice and learn programming skills and logic design in parallel. They see how robots take input from light sensors and use it to make decisions to move, similar to the human sense of sight. Students also see how they perform the steps of the engineering design process in the course of designing and testing to achieve a successful program. A PowerPoint® presentation and pre/post quizzes are provided.

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(TM) 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.

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.

Students work as engineers and learn to conduct controlled experiments by changing one experimental variable at a time to study its effect on the experiment outcome. Specifically, they conduct experiments to determine the angular velocity for a gear train with varying gear ratios and lengths. Student groups assemble LEGO MINDSTORMS(TM) NXT robots with variously sized gears in a gear train and then design programs using the NXT software to cause the motor to rotate all the gears in the gear train. They use the LEGO data logging program and light sensors to set up experiments. They run the program with the motor and the light sensor at the same time and analyze the resulting plot in order to determine the angular velocity using the provided physics-based equations. Finally, students manipulate the gear train with different gears and different lengths in order to analyze all these factors and figure out which manipulation has a higher angular velocity. They use the equations for circumference of a circle and angular velocity; and convert units between radians and degrees.

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(TM) MINDSTORMS(TM) NXT 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.

Students are introduced to gear transmissions and gear ratios using LEGO MINDSTORMS(TM) NXT robots, gears and software. They discover how gears work and how they can be used to adjust a vehicle's power. Specifically, they learn how to build the transmission part of a vehicle by designing gear trains with different gear ratios. Students quickly recognize that some tasks require vehicle speed while others are more suited for vehicle power. They are introduced to torque, which is a twisting force, and to speed the two traits of all rotating engines, including mobile robots using gears, bicycles and automobiles. Once students learn the principles behind gear ratios, they are put to the test in two simple design activities that illustrate the mechanical advantages of gear ratios. The "robot race" is better suited for a quicker robot while the "robot push" calls for a more powerful robot. A worksheet and post-activity quiz verify that students understand the concepts, including the tradeoff between torque and speed.

Students are introduced to the Robotics Peripheral Vision Grand Challenge question. They are asked to write journal responses to the question and brainstorm what information they require to answer the question. Their ideas are shared with the class and recorded. Then, students share their ideas with each other and brainstorm any additional ideas. Next, students draw a basis for the average peripheral vision of humans and then compare that range to the range of two different focal lengths in a camera. Through the associated activity provides, students see the differences between human and computer vision.

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.

Students engage in the second design challenge of the unit, which is an extension of the maze challenge they solved in the first lesson/activity of this unit. Students extend the ideas learned in the maze challenge with a focus more on the robot design. Gears are a very important part of any machine, particularly when it has a power source such as engine or motor. Specifically, students learn how to design the gear train from the LEGO MINDSTORMS(TM) NXT servomotor to the wheel to make the LEGO taskbot go faster or slower. A PowerPoint® presentation, pre/post quizzes and a worksheet are provided.

Students learn about the anatomy of the ear and how the ears work as a sound sensor. Ear anatomy parts and structures are explained in detail, as well as how sound is transmitted mechanically and then electrically through them to the brain. Students use LEGO® robots with sound sensors to measure sound intensities, learning how the NXT brick (computer) converts the intensity of sound measured by the sensor input into a number that transmits to a screen. They build on their experiences from the previous activities and establish a rich understanding of the sound sensor and its relationship to the TaskBot's computer.

Students further their understanding of the engineering design process while combining mechanical engineering and bioengineering to create an automated medical device. During the activity, students are given a fictional client statement and are required to follow the steps of the design process to create medical devices that help reduce the workload for hospital workers and increase the quality of patient care.

This lesson highlights the similarities between human sensors and their engineering counterparts. Taking this approach enables students to view the human body as a system, that is, from the perspective of an engineer. Humans have recreated most human sensors in robots – eyes, ears and sensors for temperature, touch and smell. The lesson inculdes a PowerPoint file that is programmed to run a Jeopardy-style game as a fun assessment tool.

Through six lesson/activity sets, students learn about the functioning of sensors, both human and robotic. In the activities, student groups use LEGO MINDSTORMS(TM) NXT robots and components to study human senses (sight, hearing, smell, taste, touch) in more detail than in previous units in the series. They also learn about the human made rotation, touch, sound, light and ultrasonic sensors. "Stimulus-sensor-coordinator-effector-response" pathways are used to describe the processes as well as similarities between human/animal and robotic equivalent sensory systems. The important concept of sensors converting/transducing signals is emphasized. Through assorted engineering design challenges, students program the LEGO robots to respond to input from various LEGO sensors. The overall framework reinforces the theme of the human body as a system with sensors that is, from an engineering perspective. PowerPoint® presentations, quizzes and worksheets are provided throughout the unit.