Selected by NASA as one of its top 10 finalists in the NASA iTech challenge competition, the sensor can quickly and inexpensively measure multiple contaminants in water - including viruses - that are so small they pass through bacterial filters. Such a technology holds promise for applications both in space, such as the water filtration system on the International Space Station, and on earth - anywhere where ensuring water purity is an issue.
“We came up with a method of improving the reliability of the [space station] water recycling system," says electronics engineer David Rice of Rice Technology, who designed the sensor with help from UWM. "But there are many industries that use city water and purify it by putting it through an in-house filtration system. This sensor could provide a better way to monitor harmful viruses and bacteria for places such as hospitals, research labs, and pharmaceutical companies."
The sensor comprises two sets of interlocking copper “teeth” that measure contaminants using electromagnetic fields - one set sends an electrical charge into water, and the other determines the charge decay. This creates a signal proportional to the quantity of contaminant in the water.
Initially, says UWM environmental engineer Marcia Silva, the sensor was tested for detection of suspended solids in water. When the researchers observed the device's extreme sensitivity, "we moved into phosphorus, bacteria and then viruses," Silva says.
Since testing their device with viruses is expensive, the researchers say they entered the NASA iTech competition with the hope of obtaining more funding, in addition to the chance to work with NASA professionals. While they were not ultimately chosen as one of the final three contestants, they say they are receiving interest from businesses about developing the sensor.