An information engine that rectifies nonequilibrium fluctuations

Information engines produce useful output work from heat by using feedback to rectify thermal fluctuations. We report on an experimental realization of such an engine that, when in contact with a bath that is out of equilibrium, can extract orders of magnitude more work than an information engine in contact with an equilibrium bath. We place a micron-scale bead in a harmonic potential that ratchets up, capturing favorable fluctuations. Adding a fluctuating electric field, which generates nonequilibrium fluctuations, drastically increases work extraction. Calculating the minimum thermodynamic costs to achieve feedback control, we estimate the engine's efficiency, illustrating that information engines in nonequilibrium baths can not only do more work but also be more efficient than conventional engines.