More than three decades ago, an unusual "sedimentary organism" belonging to the genus Geobacter was discovered in the muddy sediments of the Potomac River. The microbe had the unique ability to form bacterial nanowires that conduct electricity.
Scientists at the University of Massachusetts Amherst used this property to create the Air-gen device, which literally generates energy from air 24/7.
Air-gen consists of a 7 μm thick film of protein nanowires sandwiched between two electrodes, which are surrounded by normal air. Under these conditions, the nanowire film is able to adsorb atmospheric water vapor, which allows the device to generate a continuous electric current that flows between the two electrodes.
Previous studies have already shown that hydrovoltage power generation using, for example, graphene produces very short electrical pulses lasting no more than a few seconds.
Unlike graphene, Air-gen produces a stable voltage of about 0.5 V with a current density of about 17 microamperes per square centimeter. A set of several such devices will allow you to charge small gadgets - and for this you do not need anything except ordinary air (Air-gen is capable of working even in the Sahara Desert).