Maker Challenge Engineering a Photocatalytic Delivery System

Quick Look

Grade Level: High school

Time Required: 2 hours (wild guess!)

Subject Areas: Biology, Chemistry, Life Science

A photograph of a water source infested with an algae bloom. A branch surrounding the water source is holding up a portion of the algae bloom.
Algae in snow-fed creek. What can engineers to do design systems to prevent algae?
Copyright © 2005 Thayne Tuason, CC-BY-SA 4.0, Wikimedia Commons:,_Idaho.jpg

Maker Challenge Recap

Materials that absorb light are useful in engineering design, especially if they can be in place of chemicals. In this maker challenge, students are tasked with using a photocatalyst—a material which provide energy through light absorption and makes a substance react—to rid stagnant water sources of organic pollutants such as algae. Student teams engineer an application method for delivering photocatalysts to water surfaces, such as pools, ponds, and other water sources. Students will also consider the use of photocatalysts in a variety of settings and how useful they might be in their own communities.

Maker Materials & Supplies

Computers, tablets, or laptops with internet access for researching the following topics:

  • Consequences of algae in water sources
  • Current treatment methods of algae
  • Methods of photocatalysts
  • Cost of treatment methods (chemical vs. photocatalysts)

Suggested supplies for application device building:

  • wire
  • string
  • yarn
  • netting
  • plastic wrap
  • school glue
  • fast-drying glue
  • other materials at the instructor’s discretion

Suggested supplies to create the water source for testing:

  • rectangular plastic box or any container that can be used to mimic a water source such as a pool, pond, etc.

Worksheets and Attachments

Visit [] to print or download.


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Algae is a common organic pollutant that is found in a variety of water sources including pools, ponds and aquariums found in residential and commercial areas. Algae is also a common organic pollutant found in water storage and cooling ponds found in dairy farms. If algae growth gets out of control several consequences result for both people and animals.  Consequences for humans include skin rashes, and irritations, headaches, and gastrointestinal distress.  Consequences for animals include weakness, staggering, photosensitization, and even death.

Typically, the treatment to rid a water source of algae is the application of chemical substances such as chlorine and bromine, however these chemicals can have negative consequences to the organisms which utilize the treated water source. These consequences can include eye and skin irritation as well to the death or organisms living in the water such as fish and plants.

However, a photocatalyst can also be used to treat the water source. A photocatalyst is a material which absorbs light to bring it to a higher energy level and this energy then results in a chemical reaction. Photocatalysts are defined as materials which decompose detrimental substances under the sun lights containing UV rays.

Your challenge today is to design an application method for delivering photocatalysts to water surfaces such as pools, ponds and water sources which can be found on dairy farms and/or residential areas and/or businesses. At the conclusion of your project, you will create a multimedia presentation and brochure presenting the benefits of using photocatalysts as a treatment method to community members. 

As you decide on your application method make sure to research (1) current treatments of algae, (2) the action modes of photocatalysts on algae, (3) costs of both treatments, and (4) the consequences of algae in water sources.

Good luck!


Maker Time

Create groups of four students, or less. Have the groups research algae treatment and photocatalysts, and then allow them brainstorm ideas on how to create an application method for delivering photocatalysts to water surfaces such as pools, ponds and water sources found on dairy farms.

Note: To limit the number of iterations students conduct, consider having students informally present each of their ideas before they are allowed to choose supplies and build their prototype.

Students should compile a list of supplies that they will need to complete the tasks.

Following the research step, have students sketch out their ideas for each task individually using the Engineering a Photocatalytic Delivery System Worksheet. Students should then present their ideas to the group with group members providing input concerning the ideas including pros and cons.  Each group will then decide on one group idea and create a plan of action. Once an idea is chosen, students then work with their teammates to design and build their prototypes.

After students have completed the task have them create a multimedia presentation including an informational brochure. Assign each group a particular audience with the result being a multimedia presentation and informational brochure. 

Suggested information included in both:

  • Explanation of algae as an organic pollutant
  • Consequences of chemical applications to rid water sources of algae
  • Benefits of using photocatalysts to rid water sources of algae
  • The effects of photocatalysts on algae cells
  • Application method(s) for delivering photocatalysts to water sources

Wrap Up

Options include:

  • Invite members of the school and/or community to hear student presentations.
    • School/community members will suggest possible improvements.
  • Create a gallery walk in which students show off their models demonstrating the effects of photocatalysts on algae.
    • Students will suggest possible improvements.


© 2022 by Regents of the University of Colorado; original © 2021 The University of Texas at El Paso


Carlye N. Flores

Supporting Program

NSF Research Experience for Teachers, University of Texas at El Paso


This maker challenge was inspired by research conducted at the University of Texas at El Paso and was supported by the National Science Foundation under Rice University Engineering Research Center for Nanotechnology Enabled Water Treatment Systems (NEWT) RET grant no.1449500. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.

Last modified: August 18, 2022

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