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Testing the Waters 2.0

For several years, bioengineering assistant professor Unyoung (Ashley) Kim has put students to work advancing research on a device to detect water contaminants such as bacterial pathogens and arsenic in water samples collected in rural areas. What started as one professor and a couple of undergrads working on the project has blossomed into a collaborative effort that now also includes graduate students, the School of Engineering's Frugal Innovation Lab, and a partnership with St. Xavier's College in Kolkata, India. Having gone through a number of design iterations, it was time to take the device—an electrochemical sensor, CheapStat analyzer, and laptop GUI (graphical user interface)—out into the field to test the validity of its results.

JessicaVanderGeissen
Jessica VanderGeissen ’14 collects a water sample to test for pathogens in West Bengal, India.
Photo: Courtesy of Jessica VanderGeissen

So, over the course of two days in July, graduate student Jessica VanderGiessen '13 and St. Xavier's environmental studies professor Xavier Savarimuthu, S.J., gathered and tested 38 samples from the North 24 Parganas district in West Bengal, located in eastern India. "We had a few objectives going in," said VanderGiessen. "We wanted to see if the current testing protocol was appropriate in a real-world setting, we needed to determine the most efficient method for water source application, and we wanted to learn how the design of the device could be improved."

Though the plan has always been to have all the components incorporated into a handheld device such as a mobile phone, at this stage of development a laptop had to be used as part of the testing process. "The locals saw the laptop and electrode as an exhibition piece, and because Jessica is so tall, everyone was interested in seeing what she was doing," said Fr. Xavier. Despite the distraction, samples were collected and tested from shallow (30–60 ft.), midrange (80–120 ft.), and deep wells (greater than 120 ft.). To validate the instrument, Fr. Xavier selected wells that were known to have the highest peak of arsenic contamination. Later, VanderGiessen analyzed the data they had collected and wrote a report.

In a Skype call with Kim, Fr. Xavier, and Radha Basu, director of the Frugal Innovation Lab, VanderGiessen reported her findings, and the group brainstormed ideas for next steps. Ideas flew back and forth as the foursome discussed how to improve the sensitivity of their electrochemical sensor, considered adding testing for a secondary contaminant to their platform, weighed options for safe and rugged packaging, and offered suggestions for simplifying experiments by modifying their sensors to include dried reagents, eliminating the need to mix the chemicals on site. "The project will continue over the next year with improvements being made to the sensor, signal conditioning, and integration with Android to create a 'lab on a chip,'" said Basu.

Reflecting on their time together, Fr. Xavier said, "It was a hardworking trip, which involved risk of working in the monsoon season. Jessica did a fantastic job and I have followed up with some of the villagers about the quantity of arsenic that they are exposed to. This interaction helps us build a good rapport with the community that will help pave the way for future research." VanderGeissen adds, "I'm so grateful to have had this experience. This field test provided invaluable data and feedback on our current design that will be used to guide our work through the coming year."