Soft Bio-Microrobots: Toward Biomedical Applications

Soft bio-microrobots have the potential to execute complex tasks in unexpected and harsh environments of the human body due to their dexterity and flexibility. The architectural designs of soft bio-microrobots either replicate the motion of natural creatures or capitalize on their motility. Based on this design principle, biologically inspired microrobots that imitate the movements and functions of biological systems, such as starfish, bacteria, and sperm cells, as well as biohybrid microrobots that combine motile micro-organisms or cells with functional components have been developed. Herein, an overview of the design principles, energy sources, and biomedical applications of existing soft bio-microrobots is presented. It is shown that the incorporation of externally responsive material enables biologically inspired microrobots to change their shapes and imitate the motion of living organisms under external stimuli, and it is interpreted how biohybrid microrobots are guided through the tactic behavior of microorganisms or cells. Finally, perspectives on key challenges that soft bio-microrobots must overcome to achieve in vivo biomedical applications are given.