A nanoscale power-storage device has just got even smaller, thanks to a trick borrowed from the large-scale world.

Capacitors store electrical energy on the surfaces of two conducting plates separated by an insulating layer. Because they release energy more quickly than chemical batteries, they are good for providing a sudden burst of power.

In large-scale devices, the layers are usually rolled up into a cylinder to make the device more compact. Now Carlos César Bof’ Bufon and his team at the Leibniz Institute for Solid State and Materials Research in Dresden, Germany, have created nanoscale capacitors in a …