The microbial fuel cells on a paper substrate can be used to power point-of-care (POC) diagnostic biosensors. “On-demand micro-power generation is required especially for point-of-care diagnostic applications in developing countries,” said Seokheun “Sean” Choi from the Electrical and Computer Engineering Department. “Typically, those applications require only several tens of microwatt-level power for several minutes, but commercial batteries or other energy harvesting technologies are too expensive and over-qualified. Also, they pose environmental pollution issues.”
Choi, along with research assistant Maedeh Mohammadifar, created a high-performance, paper-based, bacteria-powered battery by building microbial fuel cells (MFC) with inactive, freeze-dried cells that generates power within minutes of adding saliva. The proposed battery generated reliable power with one drop of saliva, supplying on-board power that could be used by the next generation of disposable, paper-based diagnostic platforms that can be stored for long periods of time.
“The proposed battery has competitive advantages over other conventional power solutions because the biological fluid for on-demand battery activation is readily available even in the most resource-constrained settings, and the freeze-drying technology enables long-term storage of cells without degradation or denaturation,” said Choi,
“Now, our power density is about a few microwatts per centimeter square. Although 16 microbial fuel cells connected in a series on a single sheet of paper generated desired values of electrical current and voltage to power a light-emitting diode (LED), further power improvement is required for other electronic applications demanding hundreds of milliwatts of energy,” said Choi.
This follows the development of a biodegradeable paper biobattery that can be stacked to provide the necessary power.
“There’s been a dramatic increase in electronic waste and this may be an excellent way to start reducing that,” said Choi. “Our hybrid paper battery exhibited a much higher power-to-cost ratio than all previously reported paper-based microbial batteries.”
Next: Hybrid paper biobattery
The biobattery uses a hybrid of paper and engineered polymers. The polymers – poly (amic) acid and poly (pyromellitic dianhydride-p-phenylenediamine) – allow the battery to decompose. This was tested in water, clearly biodegrading without the need for special facilities, conditions or introduction of other microorganisms.
The polymer-paper structures are lightweight, low-cost and flexible and can be stacked to provide more power. “Power enhancement can be potentially achieved by simply folding or stacking the hybrid, flexible paper-polymer devices,” he said.
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