Artificial muscle with reversible and controllable deformation based on stiffness-variable carbon nanotube spring-like nanocomposite yarn

Abstract

An artificial muscle based on a stiffness-variable CNT spring-like nanocomposite yarn shows controllable and reversible deformation, and potential application.

Strong and Robust Electrochemical Artificial Muscles by Ionic‐Liquid‐in‐Nanofiber‐Sheathed Carbon Nanotube Yarns

“…The inset shows SEM image of 4 parallel integrated yarn muscles. d) Comparison of the generated isometric stress with mammalian skeletal muscles, [ 33 ] electrochemical muscles (Bucky gel (≈0.1 MPa), [ 37 ] SWNT sheet (≈0.75 MPa), [ 38 ] and CNT‐rGO (4 MPa) [ 39 ] )solvent‐driven yarn muscles (MWCNTs yarn muscles(≈1.5 MPa), [ 10 ] Wool yarn (≈2.6 MPa), [ 11 ] Flax yarn (≈8.5 MPa), [ 11 ] Catton yarn (≈9 MPa) [ 11 ] ) and heat‐driven yarn muscles (Polyamide‐6 yarn (≈0.9 MPa), [ 42 ] CNT yarn spring (≈6.8 MPa), [ 43 ] Nylon yarn (≈25 MPa), [ 44 ] UHMWPE yarn muscles [ 40 ] ). e) The isometric force of the parallel integrated yarns under different static tensile tensions, when a 0 to 4 V square wave voltage at 0.1 Hz was applied.…”

Recent advances in functional fiber electronics

“…Many natural plants can sense external environmental stimuli to autonomously fulfill different functional missions such as seed dispersal and nutrient intake. CNT-based fiber actuators can be designed to response to different stimuli, for example, electric, 25,104 solvents/vapors, 1 moisture. 26,105 Popular mechanisms to explain the actuation are molecular order (eg, LC elastomers, shape memory polymers, and dielectric elastomers) and volume change due to the mass transport, thermal volume expansion, or phase transitions.…”

“…17 Specifically, CNT fibers comprising of aligned CNT bundles have been attracting great attention owing to their advantageous properties of good electrical conductivity, superior mechanical flexibility, light weight together with satisfactory chemical stability. 12,13,18 Besides, they can be easily tailored with desired properties via engineering their microstructures or incorporating functional material into the fibers, which present broad applications in the field of supercapacitors, [19][20][21] batteries, 22,23 actuators, 2,[24][25][26][27][28] strain sensors, 29,30 etc. To date, flexible fibers with novel functions, such as high stretchability 22,31,32 and self-healing ability, 7 are also highly desirable to withstand the various deformations of bending, twisting, stretching plus the damages during daily usages, thus, satisfying the requirements of practical needs.…”

Molecular Springs: Integration of Complex Dynamic Architectures into Functional Devices

“…A reversible contraction–extension motion can be triggered by a voltage input (Figure c,d) in which the actuations were modulated by the synergy of the chirality of the ribbon helix and the helical fibers (that is, contraction for the same chirality and extension for the reverse chirality). This strategy has provided an effective protocol for the design and fabrication of electromechanical spring‐like actuators with CNTs as active materials towards potential applications like stretchable conductors and artificial muscle, and others.…”