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

University Of Cincinnati Main Campus, Cincinnati OH

Investigators

Abstract

Non-Technical Abstract Autonomous 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 Abstract Unlike 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.