Micro-Sized Microbial Fuel Cell

A new approach

With increased global population, accessibility to clean potable water is a critical need. Existing water purification technologies consume excessive power. On the contrary, the microbial fuel cell (MFC) is a promising lab based technology where electrogenic bacteria “eats” up waste from the liquids, purify it while releasing electrons – making the whole system energy efficient.

However, its technology translation is delayed due to lengthy bio-chemical reactions involved. We have made extraordinary advances to accelerate technology development: (i) using CMOS technology we batch-fabricated micro-sized MFCs with carbon nanotube as anodes for high surface to volume ratio, high conductivity and bio compatibility and Ohmic contact for improved current output.

“With increased global population, accessibility to clean potable water is a critical need.”

As a result 392 W/m3 power density was achieved; (ii) we also showed the ruggedness of the system with 45 days of continuous operation; (iii) next we replaced carbon cloth based cathode with air cathode, eliminated the use of expensive membranes and substantially shortened (from months to weeks) the time required for experimental measurements; (iv) by integrating graphene as anode, we demonstrated daily waste like saliva instead of chemically hazardous ferricyanide can be used for power generation to develop point-of-care low-cost diagnostic devices.

So where to from here then?

Listed by Scientific American as one of Top 10 World Changing Ideas 2014: Source

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