Design and Fabrication of a Low-Cost Silicone and Water-Based Soft Actuator with a High Load-to-Weight Ratio

Traditional actuators, such as motors as well as hydraulic or pneumatic artificial muscles, demonstrate excessive noise, a heavy weight, and a large size, which limit their practical application in many areas. Therefore, for many decades, scientists have worked to develop new types of silent, small, and light actuators. In this article, a novel soft actuator (actuator₃) with a high load-to-weight ratio from silicone and a low-boiling liquid (ethanol: actuator_3E or water: actuator_3W) is presented and is compared with two actuators (actuator₁ and actuator₂) fabricated according to a method described in the literature. Compared with actuator₁ and actuator₂, actuator₃ shows a larger volume expansion, output force, and load-to-weight ratio when heated. Owing to the weaker stability and repeatability of actuator_3E, many different kinds of applications based on actuator_3W are proposed, such as robotic hands and underwater rolling robots with color variations. The experimental results demonstrate that the method proposed in this article may be a viable alternative for fabricating low-cost soft actuators with high load-to-weight ratios that can be useful for future applications of soft robots.