Unipolar stroke, electroosmotic pump carbon nanotube yarn muscles

Abstract

Success in making artificial muscles that are faster and more powerful and that provide larger strokes would expand their applications. Electrochemical carbon nanotube yarn muscles are of special interest because of their relatively high energy conversion efficiencies. However, they are bipolar, meaning that they do not monotonically expand or contract over the available potential range. This limits muscle stroke and work capacity. Here, we describe unipolar stroke carbon nanotube yarn muscles in which muscle stroke changes between extreme potentials are additive and muscle stroke substantially increases with increasing potential scan rate. The normal decrease in stroke with increasing scan rate is overwhelmed by a notable increase in effective ion size. Enhanced muscle strokes, contractile work-per-cycle, contractile power densities, and energy conversion efficiencies are obtained for unipolar muscles.

Fast Sheath-driven Electrothermal Artificial Muscles with High Power Densities

“…S1&S2. Hybrid yarn muscles were made using a previous described method 19,20,33 . A CNT yarn fully in ltrated with PDMS, which is called a hybrid yarn, is noted as PDMS@CNT, a sheath driven muscle with PDMS-in ltrated CNT as sheath and PI polymer as core is expressed as PI_PDMS@CNT.…”

“…Arti cial muscles that convert external energy to mechanical energy are of great interest because of their potential applications in devices like exoskeletons, prostheses, and bionic robots. Many functional materials have been used as arti cial muscles, such as shape memory polymers (SMPs) 1,2 , shape memory alloys (SMAs) 3 , dielectric elastomers (DEs) [4][5][6][7][8] , polymer bers [9][10][11] , ionic polymer metal composites (IPMCs) 12,13 , graphene based bers [14][15][16] , and carbon nanotubes (CNTs) [17][18][19][20][21] . CNT yarns are especially promising candidates due to their high strokes, electrical conductivity, thermal conductivity, and mechanical strength 22,23 .…”

Review on Improvement, Modeling, and Application of Ionic Polymer Metal Composite Artificial Muscle

“…Artificial muscles include not only new intelligent shape memory materials that mimic the actual animal muscle structure through biotechnology, but also actuators powered by electricity, magnetic energy, or chemical energy [1][2][3]. Compared with traditional motor driving, artificial muscles have many advantages, such as versatility, a high power-to-weight ratio, and a high stressto-weight ratio, without the need for complicated connection devices [4][5][6][7]. Over the past 30 years, artificial muscle has shown great potential in applications such as bionic robots, robotic prostheses, exoskeletons, medical robots, and soft robots [8][9][10].…”

Smart Shape Memory Polyurethane with Photochromism and Mechanochromism Properties

“…Shape memory polymer (SMP) is an intelligent material that can adjust its state parameters (such as shape, position, and strain) under external stimulation, to return to the preset state and is widely used in aerospace, biomedicine, soft actuators, and other fields. [1][2][3][4][5][6][7][8][9] There are several types of SMP materials, and they can be divided into thermally, electrically, photo, magnetically, and chemically actuated SMPs. [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] At present, most SMPs are thermally actuated, and they are heated to a shape memory transition temperature T trans (T trans is the shape memory transition temperature, which is the glass transition temperature or melting transition temperature).…”