Testing Self-Heating Components for Building Inexpensive E. coli Incubators (2023)

Undergraduates: Zhihan Sun, Catherine Gorman, Brody Hill, Maddie Andrea

Faculty Advisor: Amanda Northcross
Department: Environmental Health Sciences

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E. coli found in water can cause prominent health problems that can become serious and even life-threatening if not treated with proper care and urgency. For this reason, water testing for E. coli in drinking water, specifically well water, is paramount to population safety. Currently, E.coli, a frequently employed indicator bacterium, requires multi-step procedures to correctly showcase if a water sample is contaminated. Our ultimate research goal is to manipulate self-heating components to create a cost-efficient, single-use, and nonelectric incubator that will successfully incubate a water sample testing for E. coli to correctly indicate the presence or absence of fecal bacterial contamination. This single-use incubator would significantly lower incubation costs for individuals and households, making adequate water quality more accessible and socioeconomically equitable. Hence, our research question is how we can manipulate self-heating components, incubation containers, and oxidation amounts to maintain a temperature adequate for successful E. coli incubation. After running multiple trials with different types and numbers of warmers and insolation conditions, we were able to maintain the optimum temperature range for nearly 24 hours by using eight reptile shipping warmers in one envelope. Meanwhile, we also found out trials with envelopes left completely open were most successful in reaching and maintaining range, which is likely due to the need for oxygen of the iron filament inside the warmers for heat-production reaction. Moreover, both stacking envelopes inside of each other and increasing the number of warmers applied can yield increased achievement and maintenance of the temperature range.

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