Solar cells could not only be used as standalone energy producing systems, but may also serve to power health-monitoring devices in humans. Recently, Zackary Chiragwandi at Chalmers University of Technology in Gothenburg, Sweden, and his colleagues have developed a solar cell based on a green fluorescent protein (GFP) from the jellyfish Aequorea victoria.
A droplet of GFP is added on top of two aluminum electrodes with a tiny gap between them, sitting onto a silicon dioxide substrate. The green fluorescent protein then assembles itself into strands between the two electrodes.
If exposed to light (ultraviolet in this case), the protein acts like a dye-sensitized solar cell (aka Graetzel), and produces electricity. Normally, dye-sensitized solar cells are made of titanium dioxide, a dye and a conductive substrate. It’s not the case for this one, because the green goo acts both like the titanium dioxide and the dye.
The team even did some tricks with their newly-born jellyfish solar cell. They made it work in the absence of natural light, using the light emitted from a mixture of chemicals that fireflies have (magnesium and luciferase enzymes) to feed the jellyfish protein with light and generate electricity.
This kind of cells could easily be implanted in the human body and synthesize energy from naturally-occurring chemicals.