****Technical Abstract**** This project will use a combination of experimental observations and theoretical investigations to elucidate the properties of Brownian vortexes, a newly discovered category of stochastic machines that use random thermal forces to transduce energy into motion. Whereas conventional deterministic machines waste energy punching through fluctuations, stochastic machines instead take advantage of random forces to work through their thermodynamic cycles. Unlike other stochastic machines, Brownian vortexes evolve in static force fields that combine conservative traps and non-conservative driving forces. Analogs of such systems are believed to occur in biochemical, social and financial networks. Developing a fundamental understanding of how Brownian vortexes work will provide doctoral dissertations for two graduate students and honors theses for four undergraduate Physics majors. This experimental program already has fostered the development of the first practical tractor beams and the first knotted force fields, both of which also have immediate real-world applications.
Much of our nation's technology is based on combinations of elementary machines, such as wheels, levers and screws. This project will elucidate the properties of a new type of elementary machine called a Brownian vortex that uses random thermal noise to transform energy into motion. The program's fundamental goals are to develop a deep physical understanding of how Brownian vortexes work and how to recognize and characterize them when they arise naturally in complex systems. This program will provide doctoral disserations for two graduate students and honors theses for four undergraduate Physics majors. The experiments on which these students will work take advantage of state-of-the-art techniques of optical micromanipulation, in which the forces and torques exerted by computer-designed holograms are used to create and drive microscopic machines both to advance fundamental knowledge and also for practical applications.
