Hands-on Activity: How Effective Is Your Sunscreen?

Contributed by: VU Bioengineering RET Program, School of Engineering, Vanderbilt University

Two photographs: An x-ray photograph of the sun shows an orange orb with swirls of darker and whiter regions on the sphere's surface, as well as a surrounding irregular halo of white to orange to dark orange colors surrounding it. A photograph of a grocery store shelf shows five sun protection products with labels identifying them as SPF 15 to 50 UVA/UVB protection sunscreen lotions and sprays.
How effective is your sunscreen?
copyright
Copyright © (top) Goddard Space Flight Center, NASA; (bottom) 2014 Denise W. Carlson, ITL Program, College of Engineering, University of Colorado Boulder http://rsd.gsfc.nasa.gov/rsd/images/yohkoh.html

Summary

Student teams design and conduct quality-control experiments to test the reliability of several ultraviolet protection factors. Students use UV-detecting beads in their experimental designs to test the effectiveness of various types of sunscreens and sunblock. For example, they might examine zinc oxide nanoparticles versus traditional organic sun protection factors. UV intensity is quantitatively measured by UVA and UVB Vernier sensors, and students record and graph their results. By designing and conducting this experiment, students compare various substances, while learning about quality control.
This engineering curriculum meets Next Generation Science Standards (NGSS).

Engineering Connection

This activity provides students with a lab experience in engineering design for quality control. Also, by working in groups, students learn to acknowledge and implement ideas from all members, much like engineers do in industry. The activity also includes chemical and environmental engineering connections—examining the chemical reactions that are involved when chlorofluorocarbons react to break down the ozone layer and the implications to overall public health when pollution causes this to occur, as well as laboratory-based experimentation as part of the design of new products and processes.

Learning Objectives

After this activity, students should be able to:

  • Explain how to conduct a quality control experimental design.
  • Describe how UVA and UVB sensors can be used to measure UV intensity.
  • Design a controlled one-variable experiment.
  • Test and evaluate previously determined experimental values.

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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.

  • Analyze a major global challenge to specify qualitative and quantitative criteria and constraints for solutions that account for societal needs and wants. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • Design a solution to a complex real-world problem by breaking it down into smaller, more manageable problems that can be solved through engineering. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • Medical technologies include prevention and rehabilitation, vaccines and pharmaceuticals, medical and surgical procedures, genetic engineering, and the systems within which health is protected and maintained. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • The process of engineering design takes into account a number of factors. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • Recognize that science is a progressive endeavor that reevaluates and extends what is already accepted. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • Design and conduct scientific investigations to explore new phenomena, verify previous results, test how well a theory predicts, and compare opposing theories. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • Use appropriate tools and technology to collect precise and accurate data. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • Apply qualitative and quantitative measures to analyze data and draw conclusions that are free of bias. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • Compare experimental evidence and conclusions with those drawn by others about the same testable question. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • Communicate and defend scientific findings. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • Differentiate among elements of the engineering design cycle: design constraints, model building, testing, evaluating, modifying, and retesting. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • Explain the relationship between the properties of a material and the use of the material in the application of a technology. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • Describe the dynamic interplay among science, technology, and engineering within living, earth-space, and physical systems. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
  • Understand the mathematical principles associated with the science of chemistry. (Grades 9 - 12) Details... View more aligned curriculum... Do you agree with this alignment?
Suggest an alignment not listed above

Materials List

Each student needs:

To share with the entire class:

Introduction/Motivation

In this activity, we will look at different forms of skin protection from ultraviolet light. Your challenge is to design a quality control experiment to test the protective substances. You will build on what you have learned in the previous lesson by taking a closer look at ultraviolet radiation and how the overexposure of UV radiation can have detrimental effects to humans' overall health.

We have been looking at how UV radiation can cause several types of skin cancer. Today we are going to quality control test some products with various sun protection factors (SPFs) including one that uses zinc oxide nanoparticles as a protection factor.

The skin is the body's first defense against all outside intrusion. Designing ways to protect against and detect skin cancer is one of the current focuses of biomedical engineers. Understanding, measuring and mitigating the pollution-caused deterioration of the ozone layer is another concern for engineers, because of the impact of increased UV radiation on the incidence of skin cancer. Biomedical and chemical engineers work with physicians to design and test medicines, new products and medical technologies.

Procedure

Background

Refer to the UV Radiation Designed Experiment Lab Handout for additional guidance and support for this activity. Have students complete the lab handout as they design and conduct their labs. Refer to the Lab Handout Answers and Rubric for suggested grading components.

Expect students' experimental designs and results to vary since the objective is for teams to design their own experiments. Make available a selection of items as suggested in the Materials List, so that groups have a variety of options. For example, students can use any of the provided sunscreens or sunblock, plastic bags or plastic wrap, sunglasses—as items that can filter/block/protect against UV radiation—and select a UV detector—the intensity meter and lens tester card, the UV sensitive beads or the UVA/UVB sensors. For an ultraviolet light source, they can use sunlight (if available) or the UV lamp. The intent is to mirror the controlled tests that are performed during engineering research and experimentation—to test one variable in a design at a time.

UV-sensitive beads change to random colors when exposed to UV light of either UVA or UVB wavelengths. Sunscreen will not adhere directly to the bead surface, so students must come up with ways to contain the beads in something transparent that will have minimal UV absorption, and then apply the sunscreen to that material.

For quantitative results, a UVA and UVB sensor is recommended. These can be purchased from Vernier or another scientific supply company. If probes are used, or whenever quantitative data is obtained, require students to include a graph in the data and analysis section of the lab report.

Before the Activity

With the Students

  1. Divide the class into groups of three students each. Present the engineering challenge: To design a controlled experiment to quality test the effectiveness of one aspect of current UV safety products.
  2. Direct students to choose from the given materials to design their experiments. If a group brainstorms additional materials that would aid in its design, have the group make a request to the instructor to obtain approval.
  3. Make sure students understand that this must be a one-variable (chosen by the group) controlled experiment.
  4. Have each student group explain its designed experiment to the teacher for approval. If the teacher identifies any problems with the experiment, have students revise the experiment and meet with the teacher again for approval.
  5. Once approved, have student groups conduct their experiments and gather data. If a design uses the UVA and UVB sensors, have students collect quantitative data; otherwise, students' data may be recording whether UV sensor beads change color or not, or whether the UV intensity meter and lens tester card indicates "low," "medium" or "high" UV. Whenever possible, expect students to produce graphs of their collected data to include in lab reports and presentations.
  6. Require each student to complete his or her own lab report with results typed and presented the following day. Require the following report sections: title, purpose, materials, procedure (designed by the students), data and analysis, and conclusion (which must tie back to the purpose). A grading rubric is provided on the lab handout.
  7. On the following day, have student groups discuss their lab reports, including the graphs that they created and conclusions that were drawn. Let each group decide specifically what information to prepare to present to the class.
  8. Have each group present a summary explanation of its designed experiment to the class, covering all the required sections of the lab report.

Attachments

Assessment

Pre-Activity Assessment

Pre-Lab Questions: Have students complete the pre-lab questions on the UV Radiation Designed Experiment Lab Handout, which provides a review of information taught in the associated lesson. If available, permit students to conduct research online. Gauge students' base level of knowledge as you review the answers together as a class and let students correct any incorrect answers.

Activity Embedded Assessment

Experimental Lab Design: In small groups, have students brainstorm and design experiments to test one variable. As part of each team's unique experiment design, have students select appropriate materials, write a full procedure, and once approved, conduct the experiment and gather data. Refer to the lab report grading rubric in the Lab Handout Answers and Rubric.

Post-Activity Assessment

Lab Reports & Presentations: Require students to individually turn in typed lab reports that summarize their group-designed experiments. Require the following sections: title, purpose, materials, procedure (designed by the students), data and analysis, and conclusion (which ties back to the purpose). The following day, have teams present their experiments and results to the class, recapping the report sections.

Contributors

Michelle Bell, Amber Spolarich

Copyright

© 2013 by Regents of the University of Colorado; original © 2010 Vanderbilt University

Supporting Program

VU Bioengineering RET Program, School of Engineering, Vanderbilt University

Acknowledgements

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: January 17, 2018

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