Sensors gave machines the ability to perceive things like light, altitude, and moisture by converting stimuli into ones and zeros. The coming revolution will be filled with what are called “actuators,” which do the reverse. They allow machines to simplify our world by converting those ones and zeros back into some form of force, such as light or magnetic waves, or even physical pressure that can push objects. The actuator, like the sensor before it, is part of technology’s relentless quest to make machines do more and more things with greater and greater efficiency, as epitomized by the microprocessor, the most efficient information device ever made. ... whole industries will be reshaped. The market for fossil fuels, for example, will suffer a new setback, as power for your electric vehicle can be delivered from a simple charging plate that works in much the same way your Apple Watch gets juiced up in its cradle. The life-sciences market will have to adjust to a world where tests can be performed and therapies delivered from a capsule you swallow to detect cancer. And robots that use actuators to move parts with great precision—and can be recharged wirelessly—will take on more manufacturing tasks. ... One of the most promising is made of a compound of gallium and nitride, referred to as GaN. It’s far more efficient than silicon at converting the movement of electrons into energy radiating outward.