Enabling High‐Performance Artificial Muscles via a High Strength Fiber Reinforcement Strategy

Abstract

Coiled‐polymer‐fiber‐based artificial muscles can provide large contractile actuation stroke. However, it is a challenge to achieve high actuation load and high actuation stroke for artificial muscle simultaneously. Herein, a powerful coiled‐polymer‐fiber‐based artificial muscle with a “rigid‐and‐flexible” structure is fabricated by cotwisting rigid heterocyclic aramid (HA) fibers with flexible silver‐plated nylon (SPN) fibers. The artificial muscle based on coiled HA@SPN fibers can lift a load over 108 MPa with a fast response time of 0.6 s, which is 309 times heavier than the load that human muscle can lift, and generate a work density per temperature of 41.3 J (kg °C)−1. The coiled HA@SPN fiber muscle exhibits high actuation stability of over 30 000 cycles. The coiled HA@SPN fiber muscle can provide a contractile actuation stroke of up to 8.2% and generate an average gravimetric mechanical energy density of 702 J kg−1, which is 18.1 times that of human skeletal muscle (≈38.8 J kg−1). An average contractile power density of 1168 W kg−1 is obtained for coiled HA@SPN fiber muscle, which is 23.4 times that of human skeletal muscle (≈50 W kg−1).

Fully Biosourced, Vulcanization-Free, and Thermal-Responsive Natural Rubber Material

“…As proof of the concept, a 0.4 g NR/KC band with an initial length of 6 cm is stretched to 40 cm by hanging a 100 g weight (Figure c and Movie S1). The weight can be easily lifted under the hot air blowing, demonstrating the thermal-responsive retraction behavior of NR/KC with a power density of 637J/kg, which is 50 times higher than that of mammalian muscle and also performs well in other studies of artificial muscles in Figure d. − Similarly, in Figures S5 and S6, the muscle-mimicking retraction function of NR/KC after adding nigrosin can also be triggered by electricity or infrared laser based on the joule heating effect or photothermal effect, respectively (Movies S2 and S3). These demonstrations show the scalability and great potential of NR/KC in thermal-responsive applications.…”

Construction of Spring-Shaped UHMWPE Fiber-Based Soft Actuators with Stable/Fast Actuating Response and Large Actuating Stroke

“…Soft actuators can reversibly shrink, extend, blend, or rotate in response to various external stimuli, including thermal, humidity, electrochemical, and photo, as well as solvent absorption or permeation when compared to the traditional electric motor, which has received great interest among researchers in the fields of artificial intelligence, intelligent control, visual intelligence, and soft robots. − Among them, polymer fiber-based soft actuators possess lightweight, higher energy conversion efficiency and power density, and low cost, displaying promising applications. ,− …”

Multi‐Stimuli, Large‐Stroke Hybrid Carbon Fiber‐Based Artificial Muscles

“…Twisted and coiled yarn artificial muscles generate large strokes and powerful mechanical work, which show great potential applications in soft robotics, prosthetics, and biomedical engineering. [1][2][3][4][5][6][7][8] Carbon nanotube (CNT) is one of the most DOI: 10.1002/mame.202300252 promising materials for making yarnbased artificial muscles since they are lightweight and highly electrically and thermally conductive. Infiltrated with a volume-expansive guest, the output actuation performance of CNT-based artificial muscles can be dramatically improved.…”