With photosynthesis, plants are already busy converting sunlight into usable energy. The question then is how to use plants' natural solar-power abilities to generate energy for us. In this video, an MIT researcher explains how to do just that.
As researcher Andreas Mershin explains, it's all about taking a complex of molecules called photosystem-I, or PS-I, that handle all the photosynthesis duties inside the plants and using them just like the materials in a standard photovoltaic cell so that they produce usable electricity when exposed to sunlight. The idea has been around for nearly a decade, but it's only now that scientists have figured out how to harness enough energy from the PS-I molecules to actually make the idea worthwhile.
To do that, Mershin and his team had to up the amount of PS-I that was exposed to sunlight per surface area of his device. While previous works had only place a thin layer of the molecules in the energy cell, Mershin created what he calls an "electric nanoforest", taking inspiration from densely packed pine forests. In a statement, MIT provided some further technical details on how it all works:
Mershin was able to create a tiny forest of zinc oxide (ZnO) nanowires as well as a sponge-like titanium dioxide (TiO2) nanostructure coated with the light-collecting material derived from bacteria. The nanowires not only served as a supporting structure for the material, but also as wires to carry the flow of electrons generated by the molecules down to the supporting layer of material, from which it could be connected to a circuit. As an bonus, both zinc oxide and titanium dioxide - the main ingredient in many sunscreens - are very good at absorbing ultraviolet light. That's helpful in this case because ultraviolet tends to damage PS-I, but in these structures that damaging light gets absorbed by the support structure.
There's some complicated science going on here, but the end result, Mershin hopes, is something so simple that it can be conveyed in "one sheet of cartoon instructions, without words." That would mean that isolated villages without consistent access to electricity could quickly and easily build the cells and put them to work gathering energy.
For more, check out the MIT website.