Fabrication and Locomotion of Flexible Nanoswimmers

Small-scale robots with soft joints and hinges have recently attracted interest because these components allow for more sophisticated locomotion mechanisms. Here, we investigate two different types of nanoscale swimmers as depicted in Figure 1. One consists of a rigid magnetic head linked to a semi-soft tail (1-link swimmer). Another consists of a rigid magnetic head and tail connected by a soft hinge (2-link swimmer). Both swimmers exhibit undulatory locomotion under an applied oscillating magnetic field. The speeds of the swimmers are assessed as a function of the oscillating magnetic field frequency and the sweeping angle. We find that a resonance-like frequency increases as the length decreases, and, in general, the speed increases as the sweeping angle increases. Last, we show that 2-link swimmers can also swim in a corkscrew-like pattern under rotating magnetic fields.