Self-contained soft electrofluidic actuators

Abstract

Soft robotics revolutionized human-robot interactions, yet there exist persistent challenges for developing high-performance soft actuators that are powerful, rapid, controllable, safe, and portable. Here, we introduce a class of self-contained soft electrofluidic actuators (SEFAs), which can directly convert electrical energy into the mechanical energy of the actuators through electrically responsive fluids that drive the outside elastomer deformation. The use of special dielectric liquid enhances fluid flow capabilities, improving the actuation performance of the SEFAs. SEFAs are easily manufactured by using widely available materials and common fabrication techniques, and display excellent comprehensive performances in portability, controllability, rapid response, versatility, safety, and actuation. An artificial muscle stretching a joint and a soft bionic ray swimming in a tank demonstrate their effective performance. Hence, SEFAs offer a platform for developing soft actuators with potential applications in wearable assistant devices and soft robots.

Fast Large‐Stroke Sheath‐Driven Electrothermal Artificial Muscles with High Power Densities

“…Artificial muscles that convert external energy to mechanical energy are of great interest because of their potential applications in devices like exoskeletons, prostheses, and bionic robots. Many functional materials have been used as artificial muscles, such as shape memory polymers, [1,2] shape memory alloys, [3] dielectric elastomers, [4][5][6][7][8] polymer fibers, [9][10][11] ionic polymer metal composites, [12,13] graphene-based fibers, [14][15][16] and carbon nanotubes (CNTs). [17][18][19][20][21] CNT yarns are especially promising candidates due to their high strokes, electrical conductivity, thermal conductivity, and mechanical strength.…”

Bioinspired Self-Resettable Hydrogel Actuators Powered by a Chemical Fuel

“…Inspired by the movements of soft living tissues, hydrogel-based soft actuators that can mimic biological functions have been an active area of research and discussion. − The mechanical actuation of hydrogels is usually achieved by volume change through absorbing and releasing water in and out of their networks in response to external stimuli. Along this line, diverse elegant hydrogel actuators have been created under the control of environmental parameters like pH, − temperature, − light, − electric field, − ions, − and magnetic field. − However, so far, the vast majority of the reported examples are switched between different thermodynamic equilibrium states by sequentially turning on/off the external stimuli, , showing limited autonomous capability. ,, In stark contrast, the actuation of soft living tissues is highly autonomous, which is usually realized by nonequilibrium chemical reaction networks (CRNs) powered by high-energy biomolecules, such as adenosine triphosphate (ATP). For example, muscles contract by consuming the energy released by the conversion of ATP into adenosine diphosphate (ADP) and spontaneously relax to the original state once ATP is used (Figure a). , Thus, access to autonomous hydrogel actuators powered by chemical fuels, analogous to living tissues, would be extremely advantageous for lifelike soft robotics yet remains a formidable task.…”

Flexible Electronics and Devices as Human–Machine Interfaces for Medical Robotics

“…[488] Likewise, dielectric elastomer actuators (DEAs) at human scale can only generate relatively low force (below 100 mN) but require a high working voltage (around 1000 kV) to operate. [63] In order to amplify the force output, a lot of studies have focused on the structural design of EAPs, like parallel connections [489] and hydraulic amplification. [62,490] For example, a muscle-mimetic soft EAP transducer is shown in Figure 12G.…”