Application-Oriented Low-Voltage Soft Actuators: Scenario-Based Requirements, Design Strategies, and Evaluation Metrics

Soft actuators with compliant, muscle-like deformation are used in wearable devices and soft robots that operate close to the human body. Typical current soft actuators still rely on kilovolt-level driving voltages, which force the use of large step-up power supplies and thick insulation and raise electric-shock risks, so compact on-body and portable systems are hard to realize. This conflict motivates soft actuators that reach useful deformation and force at operating voltages below or equal 1 kV, with Dielectric Elastomer Actuator (DEA), Hydraulically Amplified Self-Healing/Low-Voltage Electrostatic Actuator (HASEL/HALVE), and Ionic Polymer–Metal Composite (IPMC) as representative examples. For these three families, the working principles are discussed together with low-voltage design choices, and their influence on achievable strain, response speed, and system size is compared. Power-supply miniaturization, electrically safe encapsulation around high electric fields, and efficient use of electrical energy in the complete device emerge as the central constraints when such actuators are built into wearable, medical-rehabilitation, and service-robotic hardware.