Low-Voltage Soft Actuators for Interactive Human-Machine Interfaces

Soft electrical actuators driven by low voltages are promising for interactive human-machine interfaces (iHMI) applications including executing orders to complete various tasks and communicating with humans. The attractive features of low-voltage soft electrical actuators include their good safety, low power consumption, small system size, and nonrigid or deformable characteristics. This review covers three typical classes of electrical actuators, namely, electrochemical, electrothermal, and other electrical (dielectric, electrostatic, ferroelectric, and plasticized gel) actuators according to their mechanism and working potential range. For each kind of actuators, the advantages, working principle, device configuration/design, materials selection, recent progress, and potential applications for iHMI are summarized, with the strategies for enhancing the actuation performance under low voltages being highlighted. Finally, the challenges for those soft actuators and possible solutions are discussed.