Non-technical Abstract:<br/>Imagine a world in which roads can sense their damage and repair themselves like human skin, or in which natural disasters such as forest fires and landslides are prevented by materials that change shape and stiffness automatically, or in which clothing materials change their porosity to become personal protective equipment (PPE) when the clothing itself senses airborne pathogens. These futuristic ideas are currently science fiction, but if we have any hope of creating these amazing technologies, we need to begin today. This collaborative project seeks to explore the fundamental underpinnings of the materials needed for such applications. Specifically, in order to design any of these futuristic devices, we need to have materials that are self-powered and assembled hierarchically from energy-using building blocks. Luckily, many biological systems, such as cells, plants, and humans, are already capable of sensing their environment and responding by moving, changing shape, or releasing chemicals. The basic building blocks of these biological “systems” are enzymes, nanoscale machines made of protein that come in a variety of shapes and sizes. In order to dissect and begin to create an understanding of how enzymes can animate matter, our team will use enzymes to power new synthetic materials at the nanoscale to microscale. In the future, these nanoscale materials can be assembled themselves to create new larger scale active materials. <br/><br/>Technical Abstract:<br/>The scientific objective of this project is to understand the physics of synthetic active materials powered by enzymes. The research team combines expertise in DNA nanotechnology, enzyme kinetics, single-particle tracking, and sensitive force measurements to address the following objectives: (1) The team uses DNA origami to design, create, and characterize a suite of active particles, driven by enzyme catalysis, with programmable size, shape, flexibility, and location of propulsive enzymes. This objective addresses a need to create new nano- to mesoscale active particles and uses these particles to understand the mechanisms governing enhanced motility. (2) The team characterizes the properties of an active bath of enzyme-driven particles via the fluctuation spectrum, dissipation of energy, and the ability of an active bath to propel passive particles to extract work from noise. A combined study of the single-particle motility and the active fluctuations that emerge from collections of active particles will reveal a wealth of new information, including the mechanisms of enhanced transport of active particles, as well as a non-equilibrium statistical mechanical description of active fluctuations. The importance of this approach lies in the potential to specify the microscopic details of active particles, like their size, shape, and flexibility, and then to discover how these attributes alter the single-particle and collective behaviors.<br/><br/>This DMR grant supports research to understand the physics of synthetic active materials powered by enzymes with funding from the Condensed Matter Physics (CMP) and Biomaterials (BMAT) Programs in the Division of Materials Research of the Mathematical and Physical Sciences Directorate.<br/><br/>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.