CAREER: Bio-Enabled Actuating Materials (BEAM) to Power Autonomous Mobility

自主移动性是许多生物体的标志。在进食时，它们从自然环境中获取能量，并将其转化为运动的机械功。相比之下，大多数人造系统必须携带自己的能源，如燃料或电池，然后在预定的位置加油或充电。由于这一限制，不可能充分评估地表沃茨何时、何地以及为何受到致病微生物污染，每年造成数千人患病。解决这一挑战需要开发一种全新类型的自主移动的设备，该设备可以通过从其部署的环境中馈电来为自己供电。为了支持水生环境中的自主移动，将开发、表征和测试一类新的生物启用致动材料（BEAM）。BEAM由刺激敏感的软水凝胶组成，其中充满了名为Geophylla的产电细菌。蚯蚓以新鲜沃茨中丰富的有机物为食，并产生电荷。放电迫使水凝胶改变其形状。然后重复该过程，产生推动水凝胶的形状的振荡变化。BEAM将成为机器人、生物医学、生物传感、可穿戴纺织品、材料科学、微纳米工程等领域的众多应用平台。这个问题只能通过跨学科的方法来解决。虽然在研究生和本科生一级进行跨学科培训和参与复杂研究项目的必要性已得到广泛承认，但这种做法在学术界远未形成系统。在这个项目中，一群研究生，本科生和7-12名教师和学生，许多来自代表性不足的群体，将接受BEAM设计和合成原则以及跨学科研究和合作所需技能的培训。这些学生将能够熟练应对多方面和社会重要的工程挑战。与生物体不同，大多数工程系统必须携带自己的燃料/电池，并在预定的位置加油/充电，或者远程供电。这限制了它们在难以访问、远程供电或加油成本高昂的环境中的部署。模仿生物体的移动的全自主系统的开发将改变对偏远地区、湖泊、溪流、深海或人体腔的探索。为了在此类系统的开发中实现质的飞跃，迫切需要能够从环境中收集能量并将其转化为支持动力的新型材料。这些材料将影响从机器人、生物医学、生物传感、材料科学到微纳米工程的多个领域。在这个项目中，将开发一类新型的生物激活材料（BEAM）。BEAM含有Geolyssulfurreducens生物膜，其整合在温敏性聚N-异丙基丙烯酰胺（PNIPAAM）水凝胶的网络结构内。蚯蚓以新鲜沃茨中丰富的有机物为食，并产生电荷。放电迫使水凝胶改变其形状。然后重复该过程，产生推动水凝胶的形状的振荡变化。将合成BEAM，并研究其电化学特性，以更好地了解其从环境中获取能量的潜力。单独的研究将侧重于驱动和推进的机械性能。解决这一问题需要融合多个领域的知识和技能，只能通过跨学科的方法来解决。虽然人们普遍承认需要进行跨学科培训和参与复杂的研究项目，但学术界远未系统地采用这种做法。在这个项目中，一群研究生，本科生和7-12名教师和学生，许多来自代表性不足的群体，将接受BEAM设计和合成原则以及跨学科研究和合作所需技能的培训。研究结果将被纳入现有的课程，继续对当前和未来的学生进行跨学科培训。

Non-Technical AbstractAutonomous mobility is a hallmark of many living organisms. When feeding, they harvest energy from their natural environment and convert it into mechanical work for movement. In contrast, most man-made systems must carry their own energy sources such as fuel or batteries, and then refuel or recharge in predetermined locations. Because of this limitation, it is not possible to fully assess when, where and why surface waters become contaminated with pathogenic microbes, making thousands of people sick every year. Solving this challenge requires development of an entirely new type of autonomous, mobile devices that can power themselves by feeding from the environment where they are deployed.To support autonomous mobility in aquatic environments, a new class of Bio-Enabled Actuating Materials (BEAM) will be developed, characterized and tested. BEAM consist of stimuli-sensitive soft hydrogels populated with electricity producing bacteria called Geobacter. Geobacter feed on organics abundant in fresh waters, and produce electric charge. The discharge of electricity forces the hydrogel to change its shape. The process then repeats, creating an oscillatory change in shape that propels the hydrogel. BEAM will become a platform for many applications in robotics, biomedicine, biosensing, wearable textiles, materials science, and micro- and nano-engineering.This problem can only be tackled through an interdisciplinary approach. While the need for interdisciplinary training and involvement in complex research projects both at graduate and undergraduate levels has been widely acknowledged, such practices are far from being systemic in academia. In this project, a cohort of graduate, undergraduate and 7-12 teachers and students, many from underrepresented groups, will be trained in principles of design and synthesis of BEAM, and in skills needed for interdisciplinary research and collaboration. These students will become proficient in tackling multi-faceted and societally important engineering challenges. Technical AbstractUnlike living organisms, most engineered systems must either carry their own fuel/batteries and refuel/recharge in predetermined locations, or be powered remotely. This limits their deployment in environments that are difficult to access, cost-prohibitive for powering remotely or refueling. Development of mobile, fully autonomous systems that mimic living organisms will transform exploration of remote locations, lakes, streams, deep ocean, or human body cavities. To make a qualitative leap in development of such systems, there is urgent need for novel materials capable of harvesting energy from the environment and converting it to support motility. These materials will impact multiple fields from robotics, biomedicine, biosensing, materials science, to micro- and nano-engineering.In this project, a novel class of Bio-Enabled Actuating Materials (BEAM) will be developed. BEAM contain Geobacter Sulfurreducens biofilm integrated within the network structure of thermosensitive poly-N-isopropylacrylamide (PNIPAAM) hydrogel. Geobacter feed on organics abundant in fresh waters, and produce electric charge. The discharge of electricity forces the hydrogel to change its shape. The process then repeats, creating an oscillatory change in shape that propels the hydrogel. BEAM will be synthesized, and their electrochemical characteristics will be studied to better understand its potential to harvest energy from the environment. Separate studies will focus on mechanical properties for actuation and propulsion. Solving this problem requires amalgamation of knowledge and skills from several fields, and can only be tackled through an interdisciplinary approach. While the need for interdisciplinary training and involvement in complex research projects has been widely acknowledged, such practices are far from being systemic in academia. In this project, a cohort of graduate, undergraduate and 7-12 teachers and students, many from underrepresented groups, will be trained in principles of design and synthesis of BEAM, and in skills needed for interdisciplinary research and collaboration. Research findings will be incorporated in existing courses to continue interdisciplinary training of current and future students.