A project for CDC
AT A GLANCE
Thousands of scientific samples are discarded annually due to insufficient means to regulate and maintain adequate temperatures throughout the cold chain. We sought to develop a cold storage device for CDC that alleviates this problem and maintains temperature between
4 - 8 degrees Celsius.
User Centered Design, Interviews, Participant Observation, Affinity Mapping, Market Research & Evaluation, Prototyping,
Fusion 360, 3D Printing, Silicone Molding, Keyshot
CDC needed a solution that was affordable and relatively quick to implement. We created one device that retrofits existing commercial-off-the-shelf products with a custom designed lid. We scaled this design and created a second solution, designed for manufacture, if budget permits.
In certain parts of the world, basic water infrastructure is lacking or inadequate to meet the needs of many populations, contributing to a significanat burden of diarrheal disease and mortality in children under five years old. Increasing the availabilty and feasibility of microbiologic water quality testing in low-resource settings enables researchers, non-profits, and public health institutes to increase data-collection and provide evidence-based public health interventions.
This project examines the transportation and collection of water samples, designing for the users and contexts where field sampling occur. Existing challenges precipitated a need for a device that maintains temperature of collected water samples (4 - 8 degrees Celcius), while remaining affordable and easy to implement.
Define design criteria and imperatives to guide the development of solutions.
Develop, refine, and finalize.
Framework relevant data to unpack the motives and underlying issues behind existing solutions and compensatory behaviors.
Interview stakeholders, evaluate existing
solutions & compensatory behaviors.
During interviews, we learned that CDC currently uses coolers as the preferred mechanism to transport and collect water samples. In order to further investigate this compensatory behavior, we analyzed different types, materials, and features of existing coolers. The 2 x 2 surveys were used to inform the ergonomic qualities and the intent behind how each of the specific coolers should be used.
Unlike most laboratory and field equipment, industry-wide regulatory standards for coolers don’t exist. Product testing information varies immensely between manufacturers, making it difficult for a user to effectively compare and purchase optimal product to fit their needs.
Vacuum insulation is widely praised for its ability to maintain temperatures, but it is not currently utilized in the cooler industry primarily because of cost and form.
We interviewed two CDC researchers to learn more about the users, regulatory standards, and the testing and sample collection process.
Our biggest finding was that the key stakeholder is not the on-site CDC Researcher. It is actually the CDC Counterpart that ultimately sees a project throughout its implementation. These CDC counterparts are the central “filter” through which all the different key stakeholders must interact with in order to diagnose and respond to water bacteria challenges.
The role of the CDC researcher is to train the on-site CDC counterpart in order to reduce the number of errors and guarantee the collection of water samples ran smoothly.
ENGINEERING & HEAT TRANSFER
Ideally, the solution would prevent the three types of heat transfer: conduction, convection, & radiation. Conduction is the principal type of heat transfer the solution needs to prevent, as contact between materials allows for temperature change.
The type of heat transfer that can occur is dependent upon the state of matter through which heat is passing through the material. Modeling the existing paradigm through which heat transfers in an existing cooler was helpful in understanding where we would be able to potentially introduce a design intervention. The graphic shown in the gallery illustrates the flow of heat from the atmosphere, through the cooler's insulating material, and into the area where the sample is contained. The state of matter is important to consider as heat transfers differently through different matter. Using the heat transfer equation, it was obvious that the only way we could reduce heat transfer was through choosing materials that had an ideal material thermal conductivity coefficient as contact area, temperature, and material thickness were considered constants.
We used a variety of interpretive frameworks to analyze the concrete data we gathered. These frameworks helped us contextualize the relationships between users, time, and the particular activity they were trying to accomplish.
Design tools utilized included:
2 X 2 Matrices
User Journey Maps
Customer Experience Audit
The design team understood that the marriage of carrying the solution and the implementation of the insulation technology would ultimately define the success of the project. As a result, the team looked at who has touchpoints at each phase in the solution’s “journey” from the project’s inception through it’s conclusion. The marriage of insulation technology and the ergonomics of carrying the cooler were intrinsically related. All cooler forms were dominated by single-sling and double-sling methods of carrying. Imagining a product that was not dependent on the method of carrying was important for the design team.
From this, we developed a set of design imperatives to guide concept ideation. These imperatives tell us what a good design does, not how to achieve it. Our imperatives include criteria that encapsulates both technical and non-technical features of our solution to help guide ideation.
Concepts were developed based on carrying criteria. From the ergonomic criteria analysis, ideas were organized based on double-sling, over-the-shoulder, and independent of carrying methodology. Shown below are renders and concepts from the ideation phase.
MINIMIZING HEAT TRANSFER
After referencing our market survey of existing solutions, we decided that using materials with the lowest thermal conductivity coefficient would not be viable. Super-insulators, such as silica aerogel, do not have robust enough manufacturing methodology processes in place for us to use in our solutions. Vacuum insulation is a common insulating technique used by water bottle companies to keep liquids cold or hot for long periods of time. As it is available off the shelf, vacuum technology became the primary mechanism for keeping the water samples cold.
We conceputalized our solution as one that was carrier-agnostic, meaning that the insulating device was an isolated system that would allow for the storage and monitoring of a single sample. Looking at ideal dimensions of existing sample containers and the ideal insulating technology that was developed proved the feasibility of this particular concept.
Due to limited government funding, access to expensive, custom-designed cooling devices from manufacturers would not be financially viable for the CDC. We took our solution and designed it two ways. The first was an "ideal design" in which we could produce if we could secure funding to manufacture our design. The second was a "COTS design" as in, an alternative solution that could be easily produced using commerical off-the-shelf-products in addition to high-fidelity prototyping.