An Insect-Inspired Soft Robot Controlled by Soft Valves

Robots are becoming more and important and can support humans in all possible areas of life. Due to their inherent compliance, soft robots are ideal for human-machine interaction. In contrast to their material compliance, soft robots such as walkers are often still powered and controlled by rigid and bulky electronics. In this study, we show a walking compliant robot, which is 3D printed by FDM printers, controlled by soft, pneumatic logic gates, and powered only by a source of constant pressurized air. The robots form and gait are inspired by the stick insect (Carausius morosus). To mimic the walking gait in fast walking on horizontal planes and the interdependency of the legs, we developed bioinspired pneumatic actuators functioning as legs and implemented a novel pneumatic logic circuit. In this circuit, one pair of legs can only transition from stance to swing when the other pair of legs has touched the ground. Our results demonstrate how the field of soft robotics can advance with critical technology such as soft, pneumatic logic gates being printed on FDM printers. We envision that our system will continue to evolve with the incorporation of even more advanced control circuits, enabling the robot to operate at even higher speed. The lifting capacity has the potential to be further optimized and an on-board pressure supply system can be implemented, allowing for more efficient and effective performance. This will ultimately lead to a fully autonomous soft machine.