Maneuvering Bioinspired Soft Microrobots in Anisotropic Complex Fluids

About This Grant

Microrobots have the potential to reach deep organs to deliver drugs or perform minimally invasive surgeries. But to realize such a vision, several scientific and technological challenges need to be resolved, key among them is the design of robotic systems tailored for efficient swimming and maneuvering in biological fluids. These fluids have unique physical and rheological properties that can facilitate or hinder cell movement. Inspired by the swimming motions of sperm cells, this project aims to develop, control, and analyze the motion of magnetically driven, sperm-like soft microrobots in nanofiber fluid suspensions with properties analogous to cervical mucus. Research thrusts of this NSF funded project will be tightly coupled with comprehensive educational and outreach activities, and are designed to educate and train future scientists and engineers from diverse backgrounds in interdisciplinary research at the intersection of dynamics and control, robotics, biomaterials, and fluid mechanics. The research activities will combine experimental and computational efforts to: (a) study fluid-structure interactions of magnetoelastic undulatory microrobots in artificial cervical mucus (ACM); (b) seek optimal swimming gaits and minimal feedback controllers; (c) exploit orientation-dependent swimming behavior to detect fluid properties and steer to the microrobot to specific sites. High-resolution 3D printing will be used to fabricate soft microrobots with larger number of degrees of freedom than their rigid counterparts, leading to greater motility as they negotiate obstacles in gel-like ACMs. Remote magnetic control will drive complex flagellum beating patterns to generate straight and turning motions. In accompanying computer simulations, Immersed Boundary methods will be used to resolve fluid-structure interactions of single and multiple microrobots in ACMs, and uncover their orientation-dependent swimming mechanisms. The data will then be used with state-of-the-art multi-objective optimization tools, to construct a minimal model-free control strategy. Successful completion of these research tasks will result in a new paradigm for microrobot design, analysis, optimization, and evaluation. 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.