Scientists and engineers have long been looking for ways to capture and transform the energy of rain - the kinetic energy of many falling drops, but the breakthrough has only recently been made. Designers from Hong Kong, a region with abundant tropical rainfall, have developed a generator capable of generating 140V from a single drop of rain. This is enough to activate, for example, hundreds of small LED lamps.
The generator is based on an indium-tin alloy electrode covered with Teflon. This material has a quasi-constant surface electric charge, which easily builds up with each new drop. It remains only to bring the second aluminum electrode to it and wait until the spreading rainwater closes the circuit. In this case, the accumulated energy is released and the system is again ready for operation.
The ability to accumulate energy on the electrode and obtain significant indicators of electric current distinguishes the installation favorably from previous systems, where they tried to capture the energy of each drop separately. But even in this form, the generator is not suitable for practical use, engineers have yet to develop mechanisms for a more reliable and, most importantly, controlled process of accumulating and extracting energy.
As the authors of the development note themselves, most of all they are inspired by the possibility of scaling the system. The accumulative coating can be applied to roofs of houses and cars, to windows and walls of buildings, even to umbrellas, which will collect the energy of quadrillion raindrops. And how to apply it, they will certainly come up with later.