A MEMS Photosynthetic Electrochemical Cell Powered by Subcellular Plant Photosystems

A microelectromechanical systems (MEMS) photosynthetic electrochemical cell$(mu PEC)$was demonstrated that harnesses the subcellular thylakoid photosystems isolated from spinach cells to convert light energy into electricity. Subject to light intensity of 2000$mu mol$photons/m ²/s, it generated an open circuit voltage (OCV) of 470 mV and a current density of 1.1mu A/cm²at 5.2$mu V$. In the dark, the$mu PEC$continued to yield power for a few minutes using reduced equivalents generated during illumination, generating 330 mV OCV and 0.1mu A/cm²with a 1$ kOmega$load. The output level is comparable to other MEMS biological fuel cells previously reported. The biosolar cell was bulk-micromachined from silicon and Pyrex substrates and assembled like a fuel cell in an anode-PEM-cathode configuration. This biosolar cell could have potential to serve as a power source for micro-scale devices like remote sensors.1359