Fall 2020 Design I Final Competition

Section E: Team 4Ever

Problem Statement: How can we make necessary social spaces safer from pathogens?

Team Members: Steven Doering, James Felmlee, Joseph Hufford, and Henry Spoor

Instructor: Alina Handorean


  1. Dear team 4Ever, your presentation was done fine, though keep in mind you have a wide audience so perhaps having a teaser in the beginning would add to interest of people investing their time and wanting to know more about your product. I enjoyed the clip on demonstration of how your product works. I am not sure it was clear about the pricing, exactly? Also how many minutes does it take for an item to be completely disinfected? Will it add to wait time for people that are in line for the check stand? Can it disinfect a few items at once? And are there any items that possibly could be damaged because of the UV rays?

    • Thank you for your comment. The cost of materials and labor is around $1500 to produce one Sanitizer unit. We would sell the solution to customers for $3500 per unit. Each item on the conveyor belt stays in the sanitizer for two seconds on a standard conveyor belt (65 ft/min). In two seconds, coronaviruses are deactivated at a rate of 95%. Our solution does not focus on 100% disinfection, but rather a middle ground where employee-customer interactions feel safe while keeping lines moving at checkout counters. This will reduce the time people have to wait at stores by removing the need to chemically clean the conveyor belt every few customers. While all items can be placed as you normally would, disinfecting everything is not recommended because sensitive items such as produce can degrade in the UV-C light. We recommend placing these items in front of the Sanitizer.

    • Thank you for the comment Mirna!
      The pricing is based of cost of the intermediate materials to produce the unit and a construction time of 3 hours a per unit. The cost is currently based off constructing the unit in a garage with a single laborer, and we priced it at a value of $3,600. Using round number estimates is the easiest way of communicating pricing in my experience as I sold and installed fireplaces for a number of years successfully.

      With all 300 diode working items going through the unit can be disinfected active SARS-COV-2 viruses at a 95% in 2 seconds based off the research we conducted. The theoretical output of the UV LEDs is much grater than what was presented, but we were unable to test using the real LEDs, and only could be validated to 95%. To completely sterilize surfaces from all pathogens a longer unit would need to be produced. Each type of pathogens require different dosages of UV-C to be deactivated completely, and in our limited scope we focused on Coivd for validation.

      The UV Conveyor sanitizer can disinfect many products at one, as this UV can sterilize any surface it’s light touches. Keeping that in mind if you had 7 boxes of cereal tape together, only the expose surfaces would be disinfected. This is can slow down the check out experience as items placed on the belt by the customer need a little space between them.

      Sensitive products like produce and meats can be at risk for being damaged by UV-C light. If the customer uses the provided produce/meat bags to pre-bag their items the risk is greatly reduced, a the plastic acts as a sacrificial surface. Opaque product bags would be ideal for a store to stock, and it’s convenient that the majority of store use colored bags for different product, like at Kroger stores grey and green bags are used for produce, and pink bags for meat.

      Hopefully this answered your questions and thanks for stopping by.

  2. Hello again, Team,

    Nice video with relevant visual aids, featuring embedded video within slides and narration.

    1. Given the rate of typical grocery store checkout conveyor belt movement resulting in a predictable UVC exposure time in the box (depending on effective length of exposure container), is the time and a quality of exposure sufficient to sanitize an object passing through the box? Are the object surfaces sufficiently exposed to UVC, particularly the sides, and especially the bottoms of objects? How do you know the exposed surfaces are getting adequately dosed with UVC?
    2. Is surface contamination and spread through touching surfaces really that big of a risk for mostly airborne viruses? What does your research tell you?
    3. Though you’ve covered the costs, would you please address your value proposition when costs are weighed against benefits and time. At $4k per unit and potentially many checkout lanes, what is the value proposition to a grocery store? What are alternatives, and how do you stack up against them? What happens to the devices after the pandemic ends?

    Thank you!

    -Prof. Allam

    • Thank you for your comment Yosef!
      In the long term, businesses will save time and money by using our solution. Consider the costs of the Sanitizer solution to be the initial $3500 for the unit and maintenance on the UV-C LEDs (around $1200 every 13 years) and replacement of the conveyor belt. Over a twenty-year period for a grocery store with five checkout counters, the store will spend roughly $28,000 on the UV-C Sanitizer systems compared to $40,000 on chemical cleaners .

      The most readily available and widely used alternative are chemical cleaners. If the current use rate of chemical cleaners holds, our system will save over $10,000 for a twenty-year period with only 5 checkout counters. However, expecting the current use rate to hold is unrealistic as the pandemic fades. From our team’s research the pandemic could continue for another year, but we believe the stigma of germs and the need of stakeholders to feel “sanitary” will continue for many years going forward. Our solution will be just as effective once the pandemic ends and should be a great way to make customers feel safe for many years.

    • Thanks for the questions Yosef,
      The time of exposure is sufficient to make objects safer to handle by the worker. The surfaces exposed to the UV light are the points that the worker can grab and manipulate to scan them. The calculations for the dosage were derived to the belt surface it’s self, any object on the belt will be exposed to a higher dosage as they are closer to the emitters. The aluminum provides a great reflective surface to dose the outer edges. Validating the UV with a test would yield the best arrangement of LEDs to provide the best coverage and yield data on dosage on the sides. The bottoms of the objects will not be dosed.

      Airborne viruses are suspended in small water droplets, while they transmitted through respiration they also can enter the body through touching the face with contaminated hands. SARS-COV-2 can live on many surfaces for up to 72 hours, coming in contact with an contaminated surface can result in an infection if the individual isn’t the best at disinfecting their hands and or touching their face. Mask provide protection from the airborne vector, the sanitiser can help with the contact contamination vector.

  3. Dear all,

    Good demo of working prototype and good concept.

    A few questions…

    1) Do your costs include re-configuration of existing conveyor systems like in grocery stores, airport baggage claim and TSA stations?

    2) If not to question #1, what would you anticipate a cost to reconfigure one King Super? Would these added cost still make it beneficial?

    3) I know you have been asked about time of exposure needed. Can you expand on the min/max length of the box and speed of conveyor belt to accommodate the exposure time. Would these sizes be able to be retro fitted into check out lines, etc.??

    • Thank you for your response.

      Could you describe for me where it would be placed in a King Super? The one I go to has no space prior to the cashier. The grocery cart is right next to the cashier. The only conveyer belt is after the cashier. This would help clean the groceries bought but not help the cashiers. Am I understanding this correctly?

      • Thank you for the follow up!
        There are many different layouts of how the cash registers are arranged, however many are set up with about 6 to 8 feet of conveyor belt that’s around 18″ wide before the items get to the clerk running the register. The placement of exit of the unit would be around a foot before items reach the clerk and end of conveyor.

      • Thank you for your thoughtful responses!

    • Thank you for the question Bridget,
      The minimum length of the box is the presented configuration at a height of 2 feet from the conveyor belt to achieve the targeted 52 J/m^2. Units that would be taller need a longer footprint to achieve those power levels at the total distance. The speed of the belt also is dependent on the size of the housing and number of emitters, so a fast belt for moving cargo/luggage would need to be longer due to the time that the UV has a chance to expose effectively. The dimensions of 2 feet tall, 18 inches wide, and 2 feet long are measured to be retrofitted at the typical Kroger store, with a belt moving around 65 ft/s the UV exposes items on it for around 2 seconds. So, a larger model would require more UV light, which would raise the cost according to how drastic the increase in size is.

  4. Thanks for the questions!
    In regards to question 1 and 2 we would have to re-configure the cost only based on labor needed for initialization. We estimate that this would add around an extra $100. Since this additional cost is pretty minuscule this additional cost would still make it beneficial. In terms of re-configuring the dimensions of the system, it wouldn’t have a big impact on the actual cost of the unit because we designed our original unit to fit on basic conveyor belts which would mean that the new dimensions wouldn’t be too different for a user like King Soopers.