Stochastic Dynamics of Ripple Curvature Inversion in Freestanding Monolayers: A New Nanotechnology Source of Renewable Energy

The dynamic properties of ripples in freestanding monolayers have been exceedingly difficult to study with common experimental methods. Here, we present how to track the membrane in time using point-mode scanning tunneling microscopy. This method allows a direct measurement of the out-of-plane time trajectory and fluctuations at one point in space over long periods of time. We observe that individual ripples spontaneously invert their curvature from concave to convex. We have also successfully replicated spontaneous ripple curvature inversion using molecular dynamics simulations (LAMMPS) [see, Phys. Rev. Lett. 117, 126801 (2016)]. During curvature inversion thousands of atoms move together, in phase. Consequently, the Brownian motion is at times organized and this kinetic energy can be used to do work. The discovery of this novel motion represents a fundamental advance in our ability to harvest energy from thermal motion. For example, a single 10 nm by 10 nm ripple can produce 10 pW of power. Thus, a quartz wristwatch could be powered with a single 10 micron by 10 micron membrane.