A study published in Nature in February 2020 entitled "Power generation from ambient humidity using protein nanowires" discovered an interesting way to harvest energy from the environment, creating the potential for another clean power generating system that is self-sustaining. According to the authors, "Thin-film devices made from nanometre-scale protein wires harvested from the microbe Geobacter sulfurreducens can generate continuous electric power in the ambient environment. The devices produce a sustained voltage of around 0.5 volts across a 7-micrometre-thick film, with a current density of around 17 microamperes per square centimetre. We find the driving force behind this energy generation to be a self-maintained moisture gradient that forms within the film when the film is exposed to the humidity that is naturally present in air." The study also mentions that "connecting several devices linearly scales up the voltage and current to power electronics" and that their results "demonstrate the feasibility of a continuous energy-harvesting strategy that is less restricted by location or environmental conditions than other sustainable approaches." One of the electrical engineers, Jun Yao, from the University of Massachusetts Amherst, stated that they are "literally making electricity out of thin air." They are calling it the "Air-gen" and it generates clean energy 24/7, thanks to the electrically conductive protein nanowires produced by Geobacter.