Light-controlled 3D soft microrobots as small as the sizes of cell bodies

Light-powered micro-machines, also known as shape-memory robots, have been studied for their versatile ability to crawl, roll, jump, and slide, whereas liquid crystal polymer networks (LCNs) are extensively used. While these stimuli-responsive materials for soft microrobots claim to have achieved microscale size, they have only managed to realize the micro-thickness, rather than the entire size. This paper demonstrates a methodology for constructing light-activated 3D micro-robotics using two-photon polymerization. This approach enables the development of sophisticated architecture in tens of microscales of soft actuators, which could pave the way for the creation of cell-sized micro-robotic systems.