Watch a string vibrate in slow motion. Wiggle the end of the string and make waves, or adjust the frequency and amplitude of an oscillator. Adjust the damping and tension. The end can be fixed, loose, or open.

Students apply everything they have learned over the course of the associated lessons about waves, light properties, the electromagnetic spectrum, and the structure of the eye, by designing devices that can aid color blind people in distinguishing colors. Students learn about the engineering design process and develop three possible solutions to the engineering design challenge outlined in lesson 1 of this unit. They create posters to display their three design ideas and the comparisons used to select the best design. Then, students create brochures for their final design ideas, and "sell" the ideas to their "client." Through this activity, students complete the legacy cycle by "going public" with the creation of their informative posters and brochures that explain their designs, as well as color blindness and how people see color, in "client" presentations.

Students are presented with a challenge question concerning color blindness and asked to use engineering principles to design devices to help people who are color blind. Using the legacy cycle as a model, this unit is comprised of five lessons designed to teach wave properties, the electromagnetic spectrum, and the anatomy of the human eye in an interactive format that introduces engineering applications and real-world references. It culminates with an activity in which student teams apply what they have learned to design devices that can aid people with colorblindness in distinguishing colors— as evidenced by their creation of brainstorming posters, descriptive brochures and short team presentations, as if they were engineers reporting to clients. Through this unit, students become more aware of the connections between the biology of the eye and the physical science concept of light, and gain an understanding of how those scientific concepts relate to the field of engineering.

Students learn about the types of waves and how they change direction, as well as basic wave properties such as wavelength, frequency, amplitude and speed. During the presentation of lecture information on wave characteristics and properties, students take notes using a handout. Then they label wave parts on a worksheet diagram and draw their own waves with specified properties (crest, trough and wavelength). They also make observations about the waves they drew to determine which has the highest and the lowest frequency. With this knowledge, students better understand waves and are a step closer to understanding how humans see color.

Students learn about infrared energy and how it is used to sense the surrounding environment. They review where infrared falls on the electromagnetic spectrum and learn how infrared sensors work, as well as various ways engineers and scientists create and apply infrared technology to study science and collect information for security, communications, medical, research and other purposes. Pre/post-quizzes and a take-home assignment are provided. Learning the concepts prepares students to conduct the associated activity in which they design and program Arduino-controlled robots that use IR sensors to follow a line and make designated stops, much like the automated guided vehicles used in industry and commerce.