Collaborative Research: Enzyme-Powered, Programmable Active Matter

非技术摘要：想象一下这样一个世界：道路可以像人类皮肤一样感知损坏并自我修复，或者通过自动改变形状和硬度的材料来预防森林火灾和山体滑坡等自然灾害，或者当服装本身感知到空气中的病原体时，服装材料会改变其孔隙率，成为个人防护装备（PPE）。这些未来的想法目前是科幻小说，但如果我们有任何希望创造这些惊人的技术，我们需要开始今天。这个合作项目旨在探索这些应用所需材料的基本基础。具体来说，为了设计任何这些未来的设备，我们需要有自供电的材料，并从能源使用的积木分层组装。幸运的是，许多生物系统，如细胞、植物和人类，已经能够感知环境，并通过移动、改变形状或释放化学物质来做出反应。这些生物“系统”的基本组成部分是酶，由各种形状和大小的蛋白质制成的纳米级机器。为了剖析和开始创造一个酶如何激活物质的理解，我们的团队将使用酶来驱动新的合成材料，从纳米级到微米级。在未来，这些纳米材料可以自行组装，以创造新的更大规模的活性材料。技术摘要：该项目的科学目标是了解由酶驱动的合成活性材料的物理学。该研究团队结合了DNA纳米技术，酶动力学，单粒子跟踪和敏感力测量的专业知识，以解决以下目标：（1）该团队使用DNA折纸来设计，创建和表征一套活性粒子，由酶催化驱动，具有可编程的大小，形状，灵活性和推进酶的位置。该目标解决了创建新的纳米至中尺度活性颗粒的需要，并使用这些颗粒来理解管理增强的运动性的机制。(2)该团队通过波动光谱，能量耗散以及主动浴推动被动粒子从噪声中提取功的能力来表征酶驱动粒子的主动浴的特性。对单个粒子运动性和从活性粒子集合中出现的活性波动的综合研究将揭示丰富的新信息，包括活性粒子增强传输的机制，以及活性波动的非平衡统计力学描述。这种方法的重要性在于可以指定活性颗粒的微观细节，如它们的大小，形状和灵活性，然后发现这些属性如何改变单粒子和集体行为。该DMR资助支持研究，以了解由凝聚态物理学（CMP）和生物材料（BMAT）资助的酶驱动的合成活性材料的物理学该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Non-technical Abstract: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. Technical Abstract: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.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.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.