Soft Actuator Materials for Electrically Driven Haptic Interfaces

Abstract

Haptics involves human touch sensing and tactile feedback and plays a crucial role in physical interactions of humans with their environment. There is an ever‐increasing interest in development of haptic technologies, due to their role in various applications such as robotics, virtual and augmented reality, healthcare, and smart electronics. Electrically driven actuation mechanisms for soft materials like dielectric elastomer actuators (DEAs), electrohydraulic soft actuators (ESAs), ionic polymer−metal composites (IPMCs), and liquid crystal elastomers (LCEs) hold the potential for the development of the next generation of haptic feedback devices due to a variety of advantages such as light weight and compact design, untethered activation and control, large actuation strains, and distributed and localized actuation. Herein, a detailed look is taken at the advancement in material designs for these electrically driven soft actuators. A detailed analysis of the different strategies for improving the electromechanical performance of existing material systems is presented. Approaches adopted to synthesize novel material systems are explained. Advancements in compliant electrode materials for the electrically driven soft actuators are also described. The conclusion reflects on the main challenges in the field and provides perspectives on recent advancements expected to have a significant impact.

A Review of Recent Advances in Electrically Driven Polymer‐Based Flexible Actuators: Smart Materials, Structures, and Their Applications

“…Amongst electrically driven soft actuators, EAP are suitable to apply for haptic feedback devices compared to ETA owing to their facile fabrication, fast response, high output force, and simplistic design. [ 170 ] As shown in Figure a, a haptic device was fabricated using conductive hydrogel, silver nanowires, and conductive polymers with acrylic elastomer as the dielectric layer. [ 171 ] This haptic device showed a maximum force of 43 mN while frequency of 20 Hz was applied and the maximum height of 155 µm with a transformation time of less than a second while electric field of 21.4 V µm −1 was applied.…”

Sustainable Macromolecular Materials in Flexible Electronics

“…Studies have now gone beyond rigid mechatronic structures with the concept of soft actuators. [53] While sensors are electronic components that perform the sensing process, actuators are active circuit elements yielding motion, electrical, [54] thermal, [55] optical, [56] and chemical [57] effects, and mechanical outputs. Electrical activation can be stimulated spontaneously or created by external magnetic/electric fields.…”

Dynamic Robotic Fibers: Liquid Crystal Elastomers for Programmable and Reversible Shape-Changing Behaviors

“…Advances in material science and soft robotics are laying the foundation for rich, high-defnition tactile feedback in the feld of haptic technology [3,22]. However, current approaches hold drawbacks.…”