Effect of Body Geometry on Motile Behavior of Bio-Hybrid Microrobots

Mobile micro-robots have unique advantages such as the ability to access small spaces, and the potential to be employed in large numbers as inexpensive agents of distributed systems for swarm robotic applications. Due to these characteristics, micro-robots are envisioned to impact a diverse range of applications, including minimally invasive diagnosis, localized treatment of diseases, environmental monitoring and homeland security. Bio-hybrid micro-robotic systems are developed by integrating prokaryotic and eukaryotic cells within the robotic system. Combined with synthetic biology, bio-hybrid micro-robots are envisioned to be able to address the actuation, powering, communication and control challenges existing at micron length scales. Motility of spherical bio-hybrid microrobots actuated by attached bacteria (BacteriaBots) has been thoroughly characterized in previous literature by Behkam et al., however, a systematic study of the effect of body geometry on bacteria attachment density and propulsive behavior of BacteriaBot is currently missing. Practical applications involving microrobotics will likely benefit from non-spherical geometries with attributes such as limited particle diffusion and directional coefficient of drag . We have utilized a high throughput method based on spherical particle casting and mechanical stretching under heat to obtain new geometries which we have used to quantify the effect of microstructures’ shape on its propulsion speed and directionality of its motion.