Physics World October 26, 2018
“Feynman’s ratchet” is a microscopic heat engine that converts thermal fluctuations into work when connected to two heat sources at different temperatures. It is a way of showing how the second law of thermodynamics cannot be violated. Until now no-one has built such a tiny ratchet because of significant technical challenges that include how to prevent convection from washing out thermal fluctuations. An international team of researchers (USA – Purdue University, University of Maryland, China) has built a ratchet using a 780 nm-diameter ball of silicon dioxide confined to a 1D optical trap set up inside a small tank of water. Although the device has a very low efficiency, its creators believe it could have a number of applications, such as providing a better understanding of molecular motors that drive living cells… read more. Open Access TECHNICAL ARTICLE
Feynman’s ratchet is built at last using 19 optical tweezers
Posted in Optical tweezer and tagged Feynman's ratchet.