Hydraulically Amplified Self-Healing Electrostatic Actuator (HASEL)

HASEL 电液人工肌肉HASELAdvanced

A soft actuator that uses high-voltage electrostatics to squeeze a sealed liquid, mimicking muscle contraction.

HASEL was developed by Keplinger's group at the University of Colorado Boulder and published in Science in 2018. It's a flexible pouch filled with a liquid insulating medium, with electrodes attached to the outside; applying a high voltage pulls the electrodes together, squeezing the liquid into another part of the pouch, which bulges or contracts to produce a muscle-like motion. Because the insulating layer is a liquid, if it briefly breaks down electrically at one spot, the liquid flows back in and heals the gap — hence the name “self-healing.” It combines the fast response of electrostatic actuation with the large deformation typical of hydraulics, making it suited to soft robots and biomimetic mechanisms. Its weaknesses are the need for kilovolt-level voltage, and output force and reliability that still fall short of a robot joint motor, so it remains mostly in research and small-scale applications.

Also called: HASEL Actuator
Related: Artificial Muscle · Dielectric Elastomer Actuator (DEA) · Soft Robot · Pneumatic Artificial Muscle (McKibben Muscle) · Actuator
Sources: Acome et al., Hydraulically amplified self-healing electrostatic actuators with muscle-like performance, Science 2018