Electrothermally‐Driven Elongating‐Contracting Film Actuators Based on Two‐Way Shape Memory Carbon Nanotube/Ethylene‐Vinyl Acetate Composites

Abstract

Electrothermally‐driven shape‐memory composites (EDSMCs) are promising candidates in the field of actuators; however, they are still unable to deliver both substantial stretching strain and precise strain control, which limits their potential applications. A carbon nanotube (CNT) EDSMC composite made from ethylene‐vinyl acetate (EVA) is fabricated in this study using a novel hot‐pressing and xylene‐aided ultrasonic adsorption two‐step procedure to overcome this problem. Because of the outstanding electrical response of the CNT/EVA EDSMC, even at 50% tensile strain, it can accomplish electrothermally‐driven melting‐induced contraction (an extraordinary working limit for shape memory polymers‐based actuators). A large reversible strain and precise strain control can be integrated simultaneously with crystallization‐induced elongation at different cooling time. In addition, programmable actuation behaviors are made possible by the CNT/EVA EDSMC, which can generate predictable and diverse strain changes. Furthermore, the lightweight CNT/EVA EDSMC demonstrates good load capacity and can lift an object to 1000 times its weight. The CNT/EVA EDSMC shows durable performance under repeated elongation and contraction cycles tests over 100 times, without significant reduction of the strain precision, and had broad prospects for both engineering devices and robotics.

Review of Thermoresponsive Electroactive and Magnetoactive Shape Memory Polymer Nanocomposites

“…Other works have also exploited the weight-lifting and 2W-SM and multiple shape capabilities of SMCs. Xu et al used a poly­(ethylene- co -vinyl acetate) filled with CNTs that was activated with a voltage . Instead of using the SMC as the grip, they mounted it in a setup that permitted the opening and closing of a mechanical grip due to the elongation and contraction of the SMC during its 2W-SM effect.…”

“…Xu et al used a poly(ethylene- co -vinyl acetate) filled with CNTs that was activated with a voltage. 170 Instead of using the SMC as the grip, they mounted it in a setup that permitted the opening and closing of a mechanical grip due to the elongation and contraction of the SMC during its 2W-SM effect. Furthermore, Hu et al built a device with a magnetoresistive triple SMC that was capable of displaying text in Braille and self-refresh in order to potentially apply it as a Braille e-book.…”

Multi‐Stimuli Dually‐Responsive Intelligent Woven Structures with Local Programmability for Biomimetic Applications

“…[30] Despite its effectivity, the high voltage, indeed, limits the application of electrothermal SRMs due to humans' safety. [31] Herein, we proposed a novel strategy for fabricating an electrothermally responsive fabric featuring shape-memory and color-changing dual-response to be employed in biomimetic applications. To fulfill this purpose, the weft yarns of the fabric consisted of polyethylene terephthalate (PET) and thermochromic microcapsules (TMC) through a twin-screw extruder.…”

“…[ 30 ] Despite its effectivity, the high voltage, indeed, limits the application of electrothermal SRMs due to humans’ safety. [ 31 ]…”

Semicrystalline polymer networks with a swelling-enhanced water-triggered two-way shape-memory effect for programmable deformation and smart actuation

“…The stress-free 2W-SME can be triggered by external stimuli such as heat, [20][21][22] light, 23,24 electrical field, [25][26][27] and magnetic field. 28 Among external stimuli, thermal stimulation is the most widely used in many fields.…”