Progresses in Tensile, Torsional, and Multifunctional Soft Actuators

Abstract

Soft actuators have received intensive attention in the fields of soft robots, sensors, intelligent control, artificial intelligence, and visual intelligence. By combination of tensile and torsional deformations, different types of motions can be realized, such as bending, rolling, and jumping. Soft robotics need soft actuators, such as artificial muscles to lift or move objects to perform some work. Additionally, actuation integrated with functions of sensing, signal transmission, and control is also needed in the development of advanced intelligent systems, which further stimulates the requirement of multifunctional actuators. Here different types of soft actuators that can perform tensile and torsional actuations are summarized, including twisted fiber artificial muscles, shape memory polymers, hydrogels, liquid crystal polymers, electrochemical actuators with conducting polymers, and some natural materials. Examples are also included regarding the bending or rolling deformations of the actuators for lifting objects. Then, recent interesting reports about multifunctional soft actuators combined with sensing and signal transmission performances, are summarized. Last, a summary of different ways to realize tensile and torsional actuations, different materials, and designs for lifting or moving objects, as well as construction of multifunctional actuators with actuation and sensing functions is provided.

Electroactive macromolecular motors as model materials of ectotherm muscles

“…Otherwise the evolution of the experimental consumed energy with the material temperature follows, Fig. 9b, the theoretical description by eqn (9). In order to guarantee that the attained results only describe the temperature inuence experimental series were performed at increasing temperatures and then repeated at decreasing temperatures.…”

“…10). The energy consumed to perform any constant muscular displacement decreases at rising muscular temperatures following eqn (9), which describes both, oxidation (anodic current ow) and reduction (cathodic current ow) processes: expansion and contraction linear displacements.…”

“…The reaction-driven changes of the material volume have been used to produce electrochemical articial muscles working, as they do natural muscles, by cooperative actuation of the constitutive macromolecular motors. 2,[4][5][6][7][8][9][10] In this context, during the last years either, lms of conducting polymers, carbon nanotubes or graphenes and articial muscles made with those lms have been used as model materials and model devices in order to characterize the energetic changes during electrochemical reactions involving macromolecular machines under different temperatures. This thermal inuence has been exploited to initiate a quantitative description of the behavior of natural ectotherm muscles (coldblooded animals) from the parallel study and quantitative energetic descriptions attained by the physical chemical characterization of model materials and model devices.…”

Wearable Actuators: An Overview

“…These polymers can be electrochemically oxidized and reduced repeatedly. During the redox reaction, ions can move in or out from the CPs depending on the ion (called a dopant) and the reaction [112]. Typically, there are two different reactions.…”

Wearable Actuators: An Overview

“…These polymers can be electrochemically oxidized and reduced repeatedly. During the redox reaction, ions can move in or out from the CPs depending on the ion (called a dopant) and the reaction [114]. Typically, there are two different reactions.…”