Summary
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.Engineering Connection
In this unit, students are challenged to apply the optical concepts of refraction and interference to the problem of cancer risk analysis, as it relates to the field of biosensing. Engineers work continually to design solutions to health and medical problems that range from risk analysis to prevention, diagnosis and treatment. Many devices and procedures in use today, including diagnostic equipment, pacemakers, surgical techniques, hearing aids, laser eye surgery, ultrasound, amniocentesis, in-vitro fertilization and pain medicine, are the direct result of engineering design for medical fields. Even with these technological advances, many unanswered questions remain, and existing methods and devices can be improved.
Unit Overview
The design of this Legacy Cycle unit is composed of a contextually based Challenge Question followed by a series of instructional activities in which students brainstorm about the challenge and make predictions (Generate Ideas), then gather more information from other sources (Multiple Perspectives).
This is followed by a Research and Revise phase during which students obtain additional data and information about the challenge topic through a variety of learning activities. The cycle finishes with formative (Test Your Mettle) and summative (Go Public) assessments that lead to answering the challenge question. See below for the progression of the Legacy Cycle through this specific unit.
Research and ideas behind this way of learning may be found in How People Learn: Brain, Mind, Experience and School, (Bransford, Brown & Cocking, National Academy Press, 2000); see the entire text at https://www.nap.edu/catalog/9853/how-people-learn-brain-mind-experience-and-school-expanded-edition. Learn about the Legacy Cycle at https://iris.peabody.vanderbilt.edu/module/hpl/cresource/q2/p07/.
The Legacy Cycle is similar to the engineering design process in that they both involve identifying existing societal needs or challenges, combining science and math to develop solutions, and using research conclusions to design optimal solutions. Though the engineering design process and the Legacy Cycle both result in viable solutions, they vary in how solutions are devised and presented. See an overview of the engineering design process at https://www.teachengineering.org/design/designprocess.
In Lesson 1, Tell Me Doc—Will I Get Cancer?, students are presented with the unit's Challenge Question: "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?"
In order to discover a new way to assess a person's risk of cancer, students begin Generating Ideas by determining what they already know about cancer research and current methods of assessing cancer risk (specifically breast cancer). Then they add to their knowledge base by garnering Multiple Perspectives from sources outside the classroom, learning about optical biosensors, which guides their research towards solving the problem.
In Lesson 2, What Does Light See?, students look into to the concept of nanoscale biosensors, considering the possibilities of porous thin film as a gene detector. They also learn about the concept of light refraction, while reviewing their understanding of the concepts of diffraction and interference. Through the Bubbles and Biosensors activity, students see first-hand how refraction can work with thin film interference to produce color patterns, similar to how nanosensors work. They apply their knowledge of refraction to the original challenge question to generate a potential solution in the form of a biosensor, enabling them to extend their understanding of cancer risk analysis through gene detection, and fulfilling the Research and Revise phase of the Legacy Cycle.
In Lesson 3, Quantifying Refraction, students learn the relevant equations for refraction (index of refraction, Snell's law) and how to use them to predict the behavior of light waves in specified scenarios. Student groups work through a few example conceptual and mathematical problems. Then, through the When Silicon Talks: Refraction Equation Practice & Bio Lab Work activity, students practice using the equations in a problem set, examine data from a porous film like those used in biosensors, and apply the equations they learned to a hypothetical scenario involving biosensors. They learn about the factors that affect this interference and how to calculate exactly what will happen when each factor is manipulated in a certain way. The feedback from the activity and problem set enable students to Test Their Mettle to gauge their understanding before the summative assessment.
Finally, in Lesson 4, See the Genes: Communicating Your Work, Findings and Ideas, and its associated activity, Show Me the Genes: Making Posters to Communicate Solutions, students focus on communicating their work and ideas, a valuable skill for scientists and engineers. In their groups, students create posters depicting the solution to the unit's challenge question— how refraction of light in a porous film (an optical biosensor) can be used as a method to detect cancer-causing genes. A provided rubric guides poster preparation and grading. Individually, students complete a summative assessment quiz. This concludes the unit and serves as the culminating Go Public phase of the Legacy Cycle.
Educational Standards
Each TeachEngineering lesson or activity is correlated to one or more K-12 science,
technology, engineering or math (STEM) educational standards.
All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN),
a project of D2L (www.achievementstandards.org).
In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics;
within type by subtype, then by grade, etc.
Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.
All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).
In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.
See individual lessons and activities for standards alignment.
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- Day 1: Tell Me Doc—Will I Get Cancer? lesson
- Day 2: What Does Light See? lesson and Bubbles and Biosensors activity
- Day 3: Bubbles and Biosensors activity
- Day 4: Quantifying Refraction lesson and When Silicon Talks: Refraction Equation Practice & Bio Lab Work activity
- Day 5: When Silicon Talks: Refraction Equation Practice & Bio Lab Work activity
- Day 6: See the Genes: Communicating Your Work, Findings and Ideas lesson and Show Me the Genes: Making Posters to Communicate Solutions activity
- Day 7: Show Me the Genes: Making Posters to Communicate Solutions activity
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Students are introduced to the concept of refraction. After making sure they understand the concepts of diffraction and interference, students work collaboratively to explain optical phenomena that cannot be accounted for via these two mechanisms alone.
Students learn the relevant equations for refraction (index of refraction, Snell's law) and how to use them to predict the behavior of light waves in specified scenarios. After a brief review of the concept of refraction (as learned in the previous lesson), the equations along with their units and v...
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.
Students work in groups to create soap bubbles on a smooth surface, recording their observations from which they formulate theories to explain what they see (color swirls on the bubble surfaces caused by refraction). Then they apply this theory to thin films in general, including porous films used i...
Assessment
A two-part summative assessment for this unit is provided through the final lesson and activity.
Copyright
© 2014 by Regents of the University of Colorado; original © 2012 Vanderbilt UniversityContributors
Caleb SwartzSupporting Program
VU Bioengineering RET Program, School of Engineering, Vanderbilt UniversityAcknowledgements
The contents of this digital library curriculum were developed under National Science Foundation RET grant nos. 0338092 and 0742871. However, these contents do not necessarily represent the policies of the NSF, and you should not assume endorsement by the federal government.
Last modified: September 14, 2020
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