Embedded Conductive Fiber for Pumpless Liquid-Gas Phase Transition Soft Actuation

Area of Science:

• Robotics
• Materials Science
• Actuation Technologies

Background:

• Soft pneumatic actuators offer dexterous deformation but are limited by bulky, noisy pneumatic systems.
• Existing soft actuator designs often require complex external power sources and control mechanisms.
• The need for compact, efficient, and versatile soft actuation solutions is critical for advanced robotics.

Purpose of the Study:

• To introduce a novel pumpless pneumatic actuator design based on liquid-gas phase transition.
• To demonstrate the capability of electroconductive fiber-reinforced phase transition actuators (E-FPTAs) for high actuation strain and programmable motion.
• To explore the application of E-FPTAs in soft grippers and robotic gloves.

Main Methods:

• Embedding conductive fibers into an elastomer matrix to create flexible heating circuits and morphing elements.
• Utilizing liquid-gas phase transition for actuation, eliminating the need for external pumps.
• Mechanically programming fiber patterns to achieve diverse motion types (extending, contracting, twisting, bending, helical).

Main Results:

• E-FPTAs achieved a high actuation strain of 120% with low power input (12 W), comparable to pump-driven actuators.
• Programmable fiber patterns enabled versatile motion control.
• Successful integration into an octopus-inspired soft gripper for multimode grasping and a pumpless robotic glove with eight independent finger joints.

Conclusions:

• E-FPTAs offer a promising pumpless actuation solution, combining the large deformation of soft pneumatic actuators with the concise structure of electroactive polymer actuators.
• This design provides a significant advancement for developing compact, efficient, and versatile soft robotic systems.
• The technology opens new design insights for next-generation soft actuations in various applications.