Swimming microrobot actuated by two pairs of Helmholtz coils system

Various electromagnetic based actuation (EMA) methods have been proposed for the actuation of microrobots. The advantage of EMA is that it can generate a wireless driving force for the microrobot, and this is the reason why many researchers have focused on the EMA driven microrobot. This paper proposes a swimming microrobot driven by an external alternating magnet field using two pairs of Helmholtz coils. The microrobot with a fish like shape consists of a buoyant robot body, a permanent magnet, and a fin. Especially, the fin is directly linked to the permanent magnet and is swung by the alternating magnet field. The external alternating magnetic field generates the propulsion and steering force of the microrobot. In this paper, firstly, we design and fabricate the EMA coil system and the tadpole type microrobot. Secondly, we propose the locomotive mechanism of the microrobot using EMA. Thirdly, we set up the control system for the EMA driven microrobot. Finally, through various experiments, we demonstrate and evaluate the performance of the swimming microrobot.