Making Microrobots Move

Our group has recently demonstrated three distinct types of microrobots of progressively smaller size that are wirelessly powered and controlled by magnetic fields. For larger scale microrobots, from 1mm to 500 μm, we microassemble three dimensional devices that precisely respond to torques and forces generated by magnetic fields and field gradients. In the 500 μm to 200 μm range, we have developed a process for microfabricating robots that harvest magnetic energy from an oscillating field using a resonance technique. At even smaller scales, down to micron dimensions, we have developed microrobots we call Artificial Bacterial Flagella (ABF) that are of a similar size and shape as natural bacterial flagella, and that swim using a similar low Reynolds number helical swimming strategy. ABF are made from a thin-film selfscrolling process. In this paper I describe why we want to do this, how each microrobot works, as well as the benefits of each strategy.