Science Buddies: "Ask an Expert"

Hello! I am in 12th grade and am participating in the science fair at my school this year. Last year, I conducted an experiment in which I tested the effectiveness of various household disinfectants in killing bacteria on the surface of a phone case. I concluded that Clorox disinfecting wipes were most effective. My overall project went really well- I placed in the top 30 in my school and was looking to possibly do some sort of continuation with it this year. I want to mingle with the engineering side of experiments this year in order to make my project much more creative, innovative, and interesting. I was thinking about designing a prototype of a phone case that could basically disinfect itself. I wanted to take my results from last year (Clorox disinfecting wipes) and apply them to create the case this year. Although, I am not quite sure how I would be able to create a phone case using the primary chemicals in Clorox wipes that would be able to disinfect its surface. I considered creating a case using UV lights that one could turn on and off to shine through itself from the inside and kill bacteria on the surface. Although, I am not sure whether or not UV radiation would be effective if it had to pass through the plastic of a phone case. I also thought of making a temporary slot-case in which you could slide your phone (with its normal case on) into and it would shine UV lights onto your phone. Although, I discovered that a similar product already exists where you can place your phone into a casket-like case that charges it at the same time as it uses the UV radiation to disinfect it. I would like to know whether or not I could possibly create a case that somehow incorporates the chemicals from Clorox disinfecting wipes to disinfect its own surface. If not, I would like to know how well my idea of a case with UV lights attached to the inside, shining out would work. I also want to know if UV lights are even effective when they don’t come in direct contact with bacteria. Do you have any ideas? Any possible prototypes that I could create that might work? Thoughts and opinions on my ideas?

Thank you!

Hi erikakovalski,

Congratulations on your successful project last year. Glad to see that you're interested in continuing.

Based on the information you posted it appears that you have a great start defining your prototype for an engineering project. Either of the approaches you mention (chemical or UV light) may be feasible.

A good next step would be to work out more definition of how your prototype should work and the various features that your prototype needs.

Science Buddies has an engineering project guide that should be helpful as you work through your project:

https://www.sciencebuddies.org/science- ... cess-guide

You might want to review the “Specify Requirements” section for guidance on defining your prototype.

I hope this helps. Please post again if you have more questions.

A. Norman