Students learn more about how muscles work and how biomedical engineers can help keep the muscular system healthy. Following the engineering design process, they create their own biomedical device to aid in the recovery of a strained bicep. They discover the importance of rest to muscle recovery and that muscles (just like engineers!) work together to achieve a common goal.

Following the steps of the iterative engineering design process, student teams use what they learned in the previous lessons and activity in this unit to research and choose materials for their model heart valves and test those materials to compare their properties to known properties of real heart valve tissues. Once testing is complete, they choose final materials and design and construct prototype valve models, then test them and evaluate their data. Based on their evaluations, students consider how they might redesign their models for improvement and then change some aspect of their models and retest aiming to design optimal heart valve models as solutions to the unit's overarching design challenge. They conclude by presenting for client review, in both verbal and written portfolio/report formats, summaries and descriptions of their final products with supporting data.

As part of the engineering design process to create testable model heart valves, students learn about the forces at play in the human body to open and close aortic valves. They learn about blood flow forces, elasticity, stress, strain, valve structure and tissue properties, and Young's modulus, including laminar and oscillatory flow, stress vs. strain relationship and how to calculate Young's modulus. They complete some practice problems that use the equations learned in the lesson mathematical functions that relate to the functioning of the human heart. With this understanding, students are ready for the associated activity, during which they research and test materials and incorporate the most suitable to design, build and test their own prototype model heart valves.

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 learn the purpose of a fever in the body's immune system and how it protects the body against germs. The students continue to explore temperature by creating a model thermometer and completing a temperature conversion worksheet. They come to see how engineers are involved in designing helpful medical instruments such as thermometers.

Towards finding a solution to the unit's Grand Challenge Question about using nanoparticles to detect, treat and protect against skin cancer, students continue the research phase in order to answer the next research questions: What is the structure and function of skin? How does UV radiation affect the chemical reactions that go on within the skin? After seeing an ultraviolet-sensitive bead change color and learning how they work, students learn about skin anatomy and the effects of ultraviolet radiation on human skin, pollution's damaging effect on the ozone layer that can lead to increases in skin cancer, the UV index, types of skin cancer, ABCDEs of mole and lesion evaluation, and the sun protection factor (SPF) rating system for sunscreens. This prepares students to conduct the associated activity, in which they design quality-control experiments to test SPF substances.