Hands-on Activity How Effective Is Your Sunscreen?

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.

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.

NGSS: Next Generation Science Standards - Science

Common Core State Standards - Math

International Technology and Engineering Educators Association - Technology

State Standards

Materials List

Each student needs:

• UV Radiation Designed Experiment Lab Handout

  

To share with the entire class:

• sunscreen SPF 15
• sunscreen SPF 45
• sunblock
• sunscreen containing zinc oxide nanoparticles
• sunglasses, either ask groups that want to use sunglasses in their designed experiments to bring in sunglasses from home, or else purchase some inexpensive ones, such as https://www.qualitylogoproducts.com/tradeshow-promotions/sunglases.htm?variant=BLANK&imageID=262438&gclid=CNWLrKGq68ACFQiIaQodikAAoA
• UV sensitive beads, such as a package of 240 ultraviolet-detecting beads from Flinn Scientific at https://www.flinnsci.com/ultraviolet-detecting-beads/fb1147/
• UV intensity meter and lens tester card, at https://www.flinnsci.com/uv-intensity-meter-and-lens-tester/ap6412/
• plastic bags
• plastic wrap
• UV lamp, such as https://www.flinnsci.com/ultraviolet-lamp-hand-held/ap1901/ 
• Vernier UVA sensor, such as https://www.vernier.com/products/sensors/uv-sensors/uva-bta/
• Vernier UVB sensors, such as https://www.vernier.com/products/sensors/uv-sensors/uvb-bta/ 
• access to the outdoors

Worksheets and Attachments

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

• Gather materials and make copies of the UV Radiation Designed Experiment Lab Handout, one per student.
• Set out the supplies so groups may examine and choose experiment materials.

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.

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.

Copyright

Contributors

Supporting Program

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.