Acoustically driven microswimmer with real-time controllable motion direction

Abstract

The development of modern biomedicine needs a kind of microrobot with controllable motion direction, which relies on the driving mode of non-destructive and non-invasive biocompatibility. Acoustic drive technology is a very attractive method for driving microrobots, but most of the existing microrobots driven by acoustic wave have a single direction of motion, which is still difficult to meet the needs of biomedicine fields. In this paper, we present an microswimmer with asymmetric double tails, which is driven by the oscillation of the flexible sharp tails actuated with the acoustic wave. One or two flexible sharp tails can be selectively induced to dominate the driving force by adjusting the frequency of the acoustic wave, which makes it possible to control motion direction only changing the frequency of the acoustic wave generated by one piezoelectric transducer. The flexible microswimmer is made of polyethylene glycol diacrylate using UV photopolymerization technology with a specially designed in situ fabricated chip. The experimental results show that the microswimmer have good directional response and speed control, which is of great significance for the application research of microswimmer in biomedicine, targeted delivery and other fields.