Highest-power biological solar cell offers potential for medical devices in remote regions

The cells were developed by a team at Binghampton University, part of the State University of New York, and is intended specifically for powering lab-on-a-chip diagnostic devices, said research leader Seokheun Choi.

Such devices need a self-contained clean power source, and miniaturised biological solar cells (micro-BSCs) - where photosynthetic microorganisms are the key to electricity generation - are an attractive option because the microorganisms are self-assembling and self-maintaining.

However, Choi explains in a paper in the journal Lab on a Chip, their potential has not yet been realised because the only micro-BSCs that have been made so far have only produced power density outputs in the range of nW per cm²  — not enough for microfluidic devices — and have only lasted for a couple of hours.

Choi’s team has used a new architecture for their solar cells and has produced a system which, they claim, exhibited a greater power density than any micro-BSC system to date: a maximum output of 43.8µW per cm², and even more significant, produced sustained power of around 18.6µW per cm² during the day and around 11.3µW per cm² at night for 20 days.