Bio-Inspired Liquid Crystal Elastomer Suction Actuator for Intelligent Robotic Grasping

Abstract

Grasping operations constitute a fundamental mechanism for robotic interaction with the environment and task execution, playing a critical role in logistics, unmanned systems, and complex terrain exploration. Conventional rigid grasping devices are often bulky and exhibit limited adaptability and controllability in unstructured environments. Suction-based grippers offer improved environmental compliance but typically require extensive tubing and vacuum pumps, constraining their integration into lightweight and soft robotic platforms. Inspired by octopus suction cups, recent bioinspired designs have leveraged geometrical optimization and flexible materials to enhance adhesion, yet most still rely on external actuation or complex vacuum systems, failing to replicate the rapid, reversible adhesion achieved through muscular contraction. To address this challenge, we present a bioinspired suction actuator based on liquid crystal elastomer (LCE), exploiting their reversible anisotropic–isotropic phase transition under thermal stimuli to dynamically modulate the cavity volume and generate controllable negative pressure. The proposed design closely emulates octopus muscle mechanics while significantly simplifying structural complexity, achieving a combination of light weight, compliance, and programmability. Experiments demonstrate stable adhesion of 56 kPa on glass over 300 cycles, with rapid and reliable attachment/detachment under varying conditions, highlighting potential applications in climbing ro-bots, aerial grasping, and underwater exploration.