Modeling and analysis of wireless resonant magnetic microactuators

We present a dynamic model of the wireless resonant magnetic microactuator (WRMMA), which is a key component of the MagMite family of microrobots. We analyze the interbody force and integrate the nonsmooth and nonlinear equations of motion using a time-stepping integration scheme. We investigate the influence of system parameters, such as friction, the frequency of the applied force, the magnitude of the applied field, the effect of a clamping force, and the effect on velocity when phase shifting the clamping signal with respect to the magnetic signal. Our results are qualitatively consistent with experimental observations, and explain several nonintuitive phenomena. We show that the robots are highly sensitive to the phase of the clamping force, that the velocity can switch directions with changing frequency, and that both erratic and controlled motion occur under specific conditions.