Evaporation is a ubiquitous phenomenon in the natural environment and a dominant form of energy transfer in the Earth’s climate. Engineered systems rarely, if ever, use evaporation as a source of energy, despite myriad examples of such adaptations in the biological world. Evaporation-driven engines can power common tasks like locomotion and electricity generation. These engines start and run autonomously when placed at air–water interfaces. They generate rotary and piston-like linear motion using specially designed, biologically based artificial muscles responsive to moisture fluctuations. Using these engines, an electricity generator that rests on water can harvesting its evaporation to power a miniature car (weighing 0.1 kg) that moves forward as the water in the car evaporates. Evaporation-driven engines may find applications in powering robotic systems, sensors, devices and machinery that function in the natural environment.
In this video, Graphene 3D Lab prints a working battery.
Some bacteria produce hair-like filaments that act as wires, ferrying electrons back and forth between the cells and their environment
LaserMotive demonstrated its ability to wirelessly power UAVs (unmanned aerial vehicles) by partnering with Ascending Technologies to put LaserMotive’s receiver technology on AscTec’s Pelican quadrocopter. With only a 5-minute battery on-board, the Pelican flew for nearly twelve and a half hours!
Ambient Backscatter transforms existing wireless signals into both a source of power and a communication medium. It enables two battery-free devices to communicate by backscattering existing wireless signals. Backscatter communication is orders of magnitude more power-efficient than traditional radio communication. Further, since it leverages the ambient RF signals that are already around us, it does not require a dedicated power infrastructure as in RFID.