Dipankar Bandyopadhyay: Self-propelling Microbots Decorated with Catalytic and Magnetic Nanoparticles (joint with FLOW)

Recent advances in the fabrication of small scale devices have led to the design of artificial swimmers mimicking the movements of the microorganisms. These synthetic self-propelling objects find important applications in microfluidic transport processes, drug delivery modules, directed self-assembly, and in the design of microbots. Over the years, the locomotion of micro or nano motors has been studied originating from the gradients of temperature, chemical potential, surface tension, and electromagnetic fields. Recent experimental works suggest that micro or nano motors can also move because of differential catalytic reactions across the surface. The talk showcases examples on the fabrication and movements of microbots composed of a wide variety of commonly available materials, for example, polymer, paper, and graphene. The motors are decorated with an array of nanoparticles on the surface, which helps decomposing the solute when submerged in a solution of reactive system. The chemical reaction on the surface of the motors fuels up the solute-motor interaction and the net force originating from the solute-pressure imbalance across the motor-surface engenders motion. The in situ movement of the motors can also be controlled externally when the nanoparticles have magnetic properties. A host of interesting motions such as translation, hopping, rotation around an object, delivery to a target tissue, and to and fro movement inside microchannel are shown by tuning the nanoparticle loading, strength of external field, concentration gradient, and shape and size of the motor.

Abstract: Self-propelling Microbots Decorated with Catalytic and Magnetic Nanoparticles (doc 29 kB)