The Biomaterials program in the Division of Materials Research funds the collaborative efforts of researchers at Drexel University and University of Nevada Reno to study bacterial flagella as a component of an active biomaterial that are capable of sensing and actuation. This collaborative project is cofunded by the Nano-Biosensing program in the Division of Chemical, Bioengineering, Environmental, and Transport Systems. Bacterial flagella are helical self-assembled structures composed of flagellin subunits. Polymorphic transformations, a key property of flagella, depend on external stimuli including temperature, ionic strength, pH, optical forcing, and possibly by concentration of specific ligands. But the specific levels of stimuli needed to induce transformations have not been well-determined. The goal of the proposed work is to create a flagellar forest consisting of an array of flagella tethered to a substrate. In response to external stimuli, flagellar polymorphic transformations coupled to collective flagellar dynamics will enable the flagellar forest to sense and actuate autonomously in response to the environment. To accomplish the goal, the researchers will: (1) create flagellar forests by gathering filaments into ordered arrays tethered to magnetic motors on a substrate which are actuated by an external rotating magnetic field en masse; (2) characterize the response of individual flagella to thermal, chemical, mechanical, and optical environmental stimuli; and (3) understand how individual flagella interact to create the collective response of the flagellar forest biomaterial. The broader scientific impact of this collaborative project is in developing an understanding how macroscale autonomic behavior in biological systems that is controlled by charge and mass transport at the nanoscale, which, in turn, is controlled by the dynamic response of a vast array of polymeric biomolecules. The educational goal of this project is to effectively communicate cutting-edge research to younger and broader audiences and inspire them toward the goal of obtaining a degree in STEM fields.
The use of biological nanomaterials in an engineered system presents a critical step toward understanding how the biological world has evolved at the nanoscale, as well as how scientists and engineers can improve upon nature using modern assembly and synthesis techniques. The design of "smart" systems can take advantage of materials which can respond autonomously to changes in their surroundings. In addition, the work includes an extensive training component for graduate and undergraduate students, preparing them for careers in academia and industry with a comprehensive background in biology and engineering. Throughout the project, the PIs will continue to recruit and mentor underrepresented groups to work in STEM fields. The research will be communicated to the public through strong outreach efforts. At Drexel University, the INSPIRE academy will bring cutting-edge bionanomaterials and biomanufacturing to high school teachers and students. At the University of Nevada, Reno, the "Move Like a Microbe" program will bring this research to life for K-12 students and the public through University's "Engineer's Day", "Summer Engineering Camp", and "Mobile Engineering Education Lab" outreach programs. Additionally, web-based and social media outlets such as YouTube will be utilized to disseminate the scientific discoveries, and to make science more appealing to K-12 students, teachers and the general public.
