A solar cell converts sunlight into electricity: most of those on the market are made of a material called silicone.
MIT researchers explore the promising qualities of spinach as an energy source capable of providing electricity: the solar cells made by them use proteins from spinach and a bacterium, the Rhodobacter sphaeroides.
2 billion proteins on a glass structure constitute a "biological" layer to be alternated with a semiconductor layer: the platform thus obtained allows the proteins to absorb light and "return" electrons which produce an electric current through the semiconductor layer.
In this first, promising phase of research, the "spinach" cell is still not very efficient: it will be necessary to increase the dose of proteins present on the platform, and keep them "alive" for longer. The goal is to obtain solar cells that can self-repair and renew themselves, just like plants.
One day we may literally “grow” our own energy by watering and nourishing our biological solar cells.