Collaborative Research: Fundamentals of Power Generation from Thermal Anisotropy - A Stochastic Control Framework

University Of California-Irvine, Irvine CA

Investigators

Abstract

This NSF project aims to quantify the maximal amount of power that can be drawn from variations in temperature, or in chemical potentials, by systems that can either be engineered or exist already in the physical and biological world. Motivating paradigms include chemical concentration gradients in organisms that power biological engines as well as thermal gradients that may power nano-engines. A model gyrating engine is proposed to study theoretical limits to the maximal power and optimal efficiency that thermal engines can operate during finite-time cyclic operations. The sought quantitative theory to explain limits on how much power can be generated, and suggest ways to attain such, will have a broad range of applications in engineered systems and in gaining insights into biological ones. The intellectual merits of the project include contrasting the performance of model engines to that of naturally occurring biological processes, such as bacterial flagellar motors, and to derive theoretical bounds that limit the amount power that can be generated by physical processes. The broader impact of the project is to enable technological breakthroughs in nanoscale engines and in understanding biological processes, that in turn will bring economic and societal benefits, and inspire younger generations of students. The fundamental issue that the project aims to quantify is the tradeoff between work produced and dissipation generated by a process that operates in a cyclic manner, over a finite period, and in contact with heat baths of different temperature. Such a problem, to quantify the power that can be generated by exploiting thermal gradients has been a challenging one in classical thermodynamics, yet amenable to the tools of stochastic control that have been developed in recent years. The goal of the NSF project is to thereby advance the understanding, and develop computational tools for the analysis and synthesis of processes that act as thermodynamic gyrating engines generating power from their anisotropic thermal environment. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.