
Spider‐Inspired Electrohydraulic Actuators for Fast, Soft‐Actuated Joints
Author(s) -
Kellaris Nicholas,
Rothemund Philipp,
Zeng Yi,
Mitchell Shane K.,
Smith Garrett M.,
Jayaram Kaushik,
Keplinger Christoph
Publication year - 2021
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.202100916
Subject(s) - actuator , mechanism (biology) , torque , displacement (psychology) , hydraulic cylinder , joint (building) , computer science , mechanical engineering , spider , biomimetics , artificial muscle , robot , hydraulic machinery , power (physics) , engineering , structural engineering , physics , artificial intelligence , psychology , quantum mechanics , astronomy , psychotherapist , thermodynamics
The impressive locomotion and manipulation capabilities of spiders have led to a host of bioinspired robotic designs aiming to reproduce their functionalities; however, current actuation mechanisms are deficient in either speed, force output, displacement, or efficiency. Here—using inspiration from the hydraulic mechanism used in spider legs—soft‐actuated joints are developed that use electrostatic forces to locally pressurize a hydraulic fluid, and cause flexion of a segmented structure. The result is a lightweight, low‐profile articulating mechanism capable of fast operation, high forces, and large displacement; these devices are termed spider‐inspired electrohydraulic soft‐actuated (SES) joints. SES joints with rotation angles up to 70°, blocked torques up to 70 mN m, and specific torques up to 21 N m kg −1 are demonstrated. SES joints demonstrate high speed operation, with measured roll‐off frequencies up to 24 Hz and specific power as high as 230 W kg −1 —similar to human muscle. The versatility of these devices is illustrated by combining SES joints to create a bidirectional joint, an artificial limb with independently addressable joints, and a compliant gripper. The lightweight, low‐profile design, and high performance of these devices, makes them well‐suited toward the development of articulating robotic systems that can rapidly maneuver.