The electric current in a wall outlet is like water in a high-pressure pipe. To power a delicate chip, the pressure needs to be reduced, and this is usually done by bulky coils with iron cores. The engineers behind this work propose replacing them with a tiny plate of aluminum nitride — a crystal that vibrates at a frequency of 13.52 million times per second, converting electricity into mechanical vibrations and back.

The plate resonates like a bell after being struck: the longer it rings, the lower the losses. The researchers measured a quality factor of 1677—meaning the vibrations decay very slowly, and energy is hardly wasted. But such a bell has false overtones — spurious vibrations that corrupt the signal's purity. To eliminate them, a grounded ring was added around the plate, like a drum mute, and the spectrum became clean.

Currently, such transducers are already used in phones and chargers, but they cannot deliver high power: they overheat. The new material promises to solve this problem: it withstands high temperatures and dissipates heat like a metal. In the future, this could enable chargers the size of a coin that power a laptop or even an electric vehicle without getting hot.