By this point in the unit, students have learned all the necessary information and conceptualized a design for how an optical biosensor could be used to detect a target strand of DNA associated with a cancer-causing gene as their solution to the unit's challenge question. Now student groups act as engineers again, using a poster format to communicate and prove the validity of the design. Successful posters include a description of refraction, explanations of refraction in a thin film, and the factors that can alter the interference pattern of a thin film. The posters culminate with an explanation of what is expected to be seen in a biosensing device of this type if it were coupled to a target molecule, proven with a specific example and illustrated with drawings and diagrams throughout. All the poster elements combine to prove the accuracy and viability of this method of gene detection. Together with its associated lesson, this activity functions as part of the summative assessment for this unit.

Students are introduced to Hooke's law as well as stress-strain relationships. First they learn the governing equations, then they work through several example problems, first individually, then as a class. Through the lesson's two-part associated activity, students 1) explore Hooke's law by experimentally determining an unknown spring constant, and then 2) apply what they've learned to create a strain graph depicting a tumor using Microsoft Excel®. After the activities, the lesson concludes with a stress-strain quiz to assess each student's comprehension of the concepts.

Students are introduced to the unit challenge discovering a new way to assess a person's risk of breast cancer. Solving this challenge requires knowledge of refraction and the properties of light. After being introduced to the challenge question, students generate ideas related to solving the challenge, and then read a short online article on optical biosensors that guides their research towards solving the problem.

Through four lessons and three hands-on activities, students learn the concepts of refraction and interference in order to solve an engineering challenge: "In 2013, actress Angelina Jolie underwent a double mastectomy, not because she had been diagnosed with breast cancer, but merely to lower her cancer risk. But what if she never inherited the gene(s) that are linked to breast cancer and endured surgery unnecessarily? Can we create a new method of assessing people's genetic risks of breast cancer that is both efficient and cost-effective?" While pursuing a solution to this challenge, students learn about some high-tech materials and delve into the properties of light, including the equations of refraction (index of refraction, Snell's law). Students ultimately propose a method to detect cancer-causing genes by applying the refraction of light in a porous film in the form of an optical biosensor. Investigating this challenge question through this unit is designed for an honors or AP level physics class, although it could be modified for conceptual physics.

Student teams conduct an experiment that uses gold nanoparticles as sensors of chemical agents to determine which of four sports drinks has the most electrolytes. In this way, students are introduced to gold nanoparticles and their influence on particle or cluster size and fluorescence. They also learn about surface plasmon resonance phenomena and how it applies to gold nanoparticle technologies, which touches on the basics of the electromagnetic radiation spectrum, electrolyte chemistry and nanoscience. Using some basic chemistry and physics principles, students develop a conceptual understanding of how gold nanoparticles function. They also learn of important practical applications in biosensing.

This unit on nanoparticles engages students with a hypothetical Grand Challenge Question that asks about the skin cancer risk for someone living in Australia, given the local UV index and the condition of the region's ozone layer. The question asks how nanoparticles might be used to help detect, treat and protect people from skin cancer. Through three lessons, students learn about the science of electromagnetic radiation and energy waves, human skin and its response to ultraviolet radiation, and the state of medical nanotechnology related to skin cancer. Through three hands-on activities, students perform flame tests to become familiar with the transfer of energy in quantum form, design and conduct their own quality-control experiments to test sun protection factors (SPFs), and write nanotechnology grant proposals.

Students are presented with a biomedical engineering challenge: Breast cancer is the second-leading cause of cancer-related death among women and the American Cancer Society says mammography is the best early-detection tool available. Despite this, many women choose not to have them; of all American women at or over age 40, only 54.9% have had a mammogram within the past year. One reason women skip annual mammograms is pain, with 90% reporting discomfort. Is there a way to detect the presence of tumors that is not as painful as mammography but more reliable and quantifiable than breast self-exams or clinical breast exams? This three lesson/three activity unit is designed for first-year accelerated or AP physics classes. It provide hands-on activities to teach the concepts of stress, strain and Hooke's law, which students apply to solve the challenge problem.

In addition to the associated lesson, this activity functions as a summative assessment for the Using Stress and Strain to Detect Cancer unit. In this activity, students will create a 1-D strain plot in Microsoft Excel depicting the location of a breast tumor amidst healthy tissue. The results of this activity will function as proof of the accuracy and reliability of the students' breast cancer detection design.