Miniaturized Swimming Soft Robot with Complex Movement Actuated and Controlled by Remote Light Signals

TLDR

Powering and communicating micro robots becomes increasingly difficult as robot size shrinks, because wired connections and electronic components are limited by size and energy storage constraints. The study aims to design a micro soft swimming robot powered and controlled by remote light, eliminating the need for onboard electronics and batteries. A polymer film containing azobenzene chromophores acts as a light‑responsive motor, with UV and visible light serving as power and signal lines that periodically drive the robot’s flagellum and gripper to propel and manipulate the robot in liquid. The light‑driven design enables complex motion and control of micro robots, demonstrating the feasibility of creating even smaller robots with broad potential applications in micro‑machine and robotics.

Abstract

Abstract Powering and communication with micro robots to enable complex functions is a long-standing challenge as the size of robots continues to shrink. Physical connection of wires or components needed for wireless communication are complex and limited by the size of electronic and energy storage devices, making miniaturization of robots difficult. To explore an alternative solution, we designed and fabricated a micro soft swimming robot with both powering and controlling functions provided by remote light, which does not carry any electronic devices and batteries. In this approach, a polymer film containing azobenzene chromophore which is sensitive to ultra-violet (UV) light works as “motor” and the UV light and visible light work as “power and signal lines”. Periodically flashing UV light and white light drives the robot flagellum periodically to swing to eventually push forward the robot in the glass tube filled with liquid. The gripper on robot head can be opened or closed by lights to grab and carry the load. This kind of remotely light-driven approach realizes complex driving and controlling of micro robotic structures, making it possible to design and fabricate even smaller robots. It will have great potential among applications in the micro machine and robot fields.