Spring 2020 Design I Final Competition

Section W: SAS-E Sprayer

Problem Statement: How might we sanitize desks at the Colorado School of Mines more safely, efficiently, and effectively?

Team Members: Randall Spitz, Jenna Haskett, Jesus Ortiz, and Calli Taylor

Instructor: Ryan Meyer


  1. How do you envision that the surface gets dry from the wet cleaning material? Does it require manual wiping with paper towels? Or does the cleaning material naturally dry? Also can your nozzle be adjusted to ensure that the entire surface area is covered by the spray.

    Good job creating the prototype.


    • Hello Peter;

      Thank you for taking the time to watch our demonstration!

      The sanitizer will evaporate off on its own. The mist nozzles that we ended up ordering did not match their product description and that’s why in the video you see the sanitizer pool up on the table. In the final solution, the mist nozzles would apply the sanitizer in a lighter coat rather than pooling. And the other mist nozzles that we looked at are adjustable for the table that they will be fitted to.

      Many thanks,

  2. Hi Team,

    This is an interesting prototype, but I do have some follow up questions:

    For the UV light – is there risk to humans nearby of harmful UV exposure while it is sanitizing?

    What is the average surface area coverage for both the UV sanitization and the spray?

    Is there risk of an added tripping hazard from the cords/tubing, and how would that be mitigated?

    • Greetings Patricia,

      UV lights are dangerous to humans, causing mild sunburns. This is why we decided that the UV light will only run at night (at sometime around midnight, when no students are in classrooms), to ensure that no one is harmed. With that, the mist nozzles will run in between classes to ensure that the desks are cleaned thoroughly and all virus/bacteria is killed when new students come into classrooms.

      The mist nozzles and pump can be adjusted to spray different lengths. This way, the S.A.S-E sprayer can be adjusted for different sized desks. The UV light covers a 6 foot radius, meaning that it will cover not only the desks during the night but also chairs, to ensure a fully sanitized and virus-free classroom.

      While the cords and tubing could pose a tripping hazard, cable guards will be used once the S.A.S-E sprayers are installed in classrooms. For a more permanent fixture, holes can be drilled in the desks (if the school is willing) so that the cords are just underneath the table, and not along it.

      Thank you so much for viewing our video,
      Calli Taylor

      • Hello Patricia,

        Thank you so much for taking the time to view our demonstration. And just to elaborate on a few things that were said above by Calli Taylor.

        The sanitizer and UV light can also be used manually by the two buttons on the front and can be run either by this manual option or an automated system using the time on the sprayer through software. There would also be checks in place to ensure that the UV could be used and not be a harm to anyone nearby, such as motion/light sensors, or a prompt on the computer that all the systems are hooked up to.

        Thank you once again,

  3. Hello again, SAS!

    Nice video, and again, very nice prototype. As I’ve already peppered you with some questions in the preliminary round, here are a few new “zingers” for you to consider.

    1. What are the major differences in the functionalities, feature set, components, materials, and fabrication for your works-like prototype shown here versus an envisioned, idealized production model that would be available for purchase?
    2. Are there to be limitations on the sanitizing options available based on a given setting, time of day, etc., and how would these be enforced or who would set them?
    3. In what ways and settings would this design remain relevant and applicable in a post-pandemic world?

    Thanks and it is nice to interact with you again.

    -Prof. Allam

    • Hello, again Professor Allam;

      Thank you so much for taking the time to watch the video again and provide us with questions!

      1. The major differences between the prototype and the final solution are that we would have a UV-C bulb installed rather than the LED pictured. We would have the units all hooked up to one computer so that the user can set exactly what time(s) they want both the UV and sanitizer to automatically go off. Also, the mist nozzles would be slightly different as the ones that we ended up ordering were lower quality and that’s why you see the sanitizer pool up in the video, the new ones would do a much better job evenly spraying the entire surface. We would also look into adding a motion/light sensor as well as warnings on the unit to not use it around people. However, apart from those few things, everything else would remain mostly the same in the final unit.

      2. During the day, the user would have an additional confirmation to activate sanitizer disinfecting, whether that be by having to press the activate button twice to confirm it, or the computer all the sprayers are hooked up to might prompt for confirmation, would be up to the user. With the UV light, we would require the computer that all of the units are hooked up to, to prompt the user that a sprayer is trying to use UV outside of normal hours and ask if they would like to proceed. All of these settings would be customizable to the user’s preferences, including the default time for everything to go off.

      3. The SAS-E sprayer could remain installed at most if not all locations to sanitize surfaces on a regular basis to help general cleanliness and keep people safer from contracting the common cold, the flu, or other major viral infections. A restaurant would be a great example of this because rather than manually cleaning each and every table between customers, a button could be pressed, and the sprayer will do the rest.

      Thank you so much once again for taking the time to reach out to us with your questions,