CAREER: Actuating robots with actomyosin active gels

University Of Texas At Austin, Austin TX

Investigators

Abstract

Non-technical Abstract Gels of the proteins actin and myosin exist in virtually every mammalian cell. These gels are capable of exerting contraction forces, which allow cells to move, divide, and change shape. Although it is well known that these gels consume chemical energy and exert mechanical power, the relationship between energy consumption and power exertion is not well understood. This proposal aims to quantify this relationship by measuring both the energy consumption and mechanical power simultaneously. This work will directly address the energy-consuming nature of materials containing actin and myosin, which will elucidate how these proteins can deform cells and tissues. Furthermore, this proposal will develop gels of actin and myosin as actuators for soft robots. These robots will take advantage of the dynamic nature of actin-myosin gels to switch on-the-fly between optimal states. In addition, this research will inspire an educational robotics project that seeks to build a robot that is powered by the expulsion of a fluid. Technical Abstract Active matter, including active gels of the cytoskeletal proteins actin and myosin, comprises a fascinating class of systems wherein macroscopic phenomena emerge from a microscopic consumption of chemical energy. Can this energy consumption be harnessed to power mechanical tasks? This question has been extensively explored in the context of active fluids, which can rotate gears and drive flows. More recently, theoretical studies have looked at the work done by self-propelled particles. However, existing studies have not investigated cases where active gels deform their environment. Thus, the mechanical power output of cytoskeletal actomyosin gels remains poorly understood. The existence of this problem is surprising, considering the central role that the actomyosin cytoskeleton plays in driving deformations on cellular and tissue levels. This proposal aims to quantify the relationship between microscopic energy consumption and macroscopic power exertion by measuring both the energy consumption and mechanical power simultaneously. Furthermore, this proposal will develop the principles of applying such gels as actuators for various soft-robotics applications. 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.