Photo-Driven Sperm-Inspired Microrobots Serving in Liquid Environments

Bionic microrobots working in liquid environments have attracted attention in recent years, because they play an important role in the medical fields. So far, most bionic microrobots serving in liquid environments (swimming microrobots) are fabricated based on organic materials. Limited by the inherent property of organic materials, the performance and lifetime of the swimming microrobots are still deficient. Facing this challenge, inspired by sperms, swimming microrobots based on the inorganic phase transition driving material vanadium dioxide are developed. In liquid environments, the linear and rotary motion of these sperm-like micro-robots could be controlled by changing the laser modulation frequency. The highest linear speed attained is 56 μm s⁻¹, and the highest rotary speed attained is 14° s⁻¹. The microrobot is able to undergo more than 10⁵ cycles in a liquid environment without degradation of its performance. Considering its high performance and controllability, the swimming microrobot is expected to be helpful in medical applications such as precision drug delivery and minimally invasive surgery.