Muscles, artificial composites

Chemically active plastics such as the polyelectrolytes have been used to make artificial muscle materials. This is an unusual type of mechanical power device that creates motion by the lengthening and shortening of fibers made from a chemically active plastic by changing the composition of the surrounding liquid medium, either directly or by the use of electrolytic chemical action. Obviously this form of mechanical power generation is no competitor to thermal energy sources, but it is potentially valuable in detector equipment that would be sensitive to the changing... 

The presence of polymer, solvent, and ionic components in conducting polymers reminds one of the composition of the materials chosen by nature to produce muscles, neurons, and skin in living creatures. We will describe here some devices ready for commercial applications, such as artificial muscles, smart windows, or smart membranes other industrial products such as polymeric batteries or smart mirrors and processes and devices under development, such as biocompatible nervous system interfaces, smart membranes, and electron-ion transducers, all of them based on the electrochemical behavior of electrodes that are three dimensional at the molecular level. During the discussion we will emphasize the analogies between these electrochemical systems and analogous biological systems. Our aim is to introduce an electrochemistry for conducting polymers, and by extension, for any electrodic process where the structure of the electrode is taken into account. 

A new composite PVA hydrogel for an artificial muscle has been prepared by a freezing and thawing method [71]. The gel contained PAA and PAAm.HCl (poly-allylamine hydrochloride). The electrocontractile behavior of the composite gel in various solutions was studied. A large stroke and better controllability have been detected in a 10 mM NaOH/7 mM Ba(OH)2 system. 

In addition to their potential use as structural composites, these macroscopic assemblies of nanocarbons have shown promise as mechanical sensors [83], artificial muscles [84], capacitors [85], electrical wires [59], battery elements [85], dye-sensitized solar cells [86], transparent conductors [87], etc. What stands out is not only the wide range of properties of these type of materials but also the possibility of engineering them to produce such diverse structures, ranging from transparent films to woven fibers. This versatility derives from their hierarchical structure consisting of multiple nano building blocks that are assembled from bottom to top. 

FIGURE 8.8 Composite of a nonionic polyurethane core of an artificial muscle. 

A minor measure of civilization s progress is that television androids now look more realistic their limbs flex like a human s. Artificial joints and muscles are becoming more realistic as new lightweight soft technologies replace the steels of the industrial age and even the plastics of the twentieth century. Some new materials flex when an electrical impulse is passed through, and others expand more than 100 times when the temperature is raised by 1°C. The nonmetals and metalloids play an important role in these new materials, especially in gels, composite materials, ceramics, polymers, artificial muscle, and luminescent materials. 

Composite Organic Materials Could Yield Stronger Artificial Muscles, MD DI, Nov. 2002. 

Kim KJ, Shahinpoor M (2002) A novel method of manufacturing three-dimensional ionic polymer-metal composites (IPMCs) bomimetic sensors, actuators and artificial muscles. Polymer 43 797... 

Finkelmann H, Shahinpoor M (2002) Electrically controllable liquid crystal elastomer-graphite composite artificial muscles. Proc SPIE 4695 459... 

Shahinpoor M, Kim KJ (2004) Ionic polymer-metal composites ID. modeling and simulation as biomimetic sensors, actuators, transducers and artificial muscles (review paper). Smart Mater Struct Int J 13(6) 1362-1388. doi 10.1088/0964-1726/13/6/009... 

Shahinpoor M (2003) Ionic polymer-conductor composites as biomimetric sensors, robotic actuators and artificial muscles—a review. Electrochim Acta 48(14-16) 2343-2353... 

Shahinpoor M, Bar-CohenY, Xue T, Harrison IS, Smith 1 (1999) Ionic polymer-metal composites as biomimetic sensors and actuators-artificial muscles. In Khan IM, Harrison JS (eds) Field responsive polymers. ACS Symp Series, Washington DC. doi 10.1021/bk-1999-0726.ch003... 

The Artificial Muscle Project draws people from a variety of disciplines. Indeed, the field of electroactivity is extremely interdisciplinary. Case in point for my first patent in this area, the examiner from the USPTO called me. Evidently, they had several meetings trying to decide which patent classification code it came under—chemistry or electrical engineering So they resolved the matter by putting the question to me. We chatted and I agreed that it was on the fence between the two areas, but since my background was stronger in chemistry, the main classification was placed in class 523/113, synthetic resins, subclass composition suitable for use as tissue or body member replacement, restorative, or implant. 

S. Kara, T. Zama, W. Takashima, and K. Kaneto, Pol) pyrrole-metal coil composite actuators as artificial muscle fibers, Synth. Met., 146 (1), 47-55 (2004). 

Palmre V, Pugal D, Kim KJ, Leang KK, Asaka K, Aabloo A (2014) Nanothom electrodes for ionic polymer-metal composite artificial muscles. Sci Rep 4 6176... 

Conventional manufacturing and production processes do not generally lend themselves to mimicking complex architectures found in nature. Layered manufacturing methodology is a very effective way of exploring 2D layered mechanisms, common in the natural world. Artificial muscles and smart soft composite prototypes can be produced cheaply and efficiently (Weiss et al., 1997 Ahn et al., 2012), yetpose limitations in the realization of more complex 3D mechanisms that utilize fiber orientation. 

The unique properties of high strength, robustness, good conductivity and pronounced electroactivity make these fibers potentially useful in many electronic textile applications. PANi-SWNTs composite fibers are currently being considered for application in artificial muscles, sensors, batteries and capacitors. 

Throughout the chapters of this book we considered several types of electroactive materials in a view of using them as biomimetic artificial muscles. In particular, ionic polymer-metal composites, conjugated polymers, and dielectric elastomers were considered. 

Shahinpoor, M., Bar-Cohen, Y., Simpson, J. O. and Smith, J. (1998). Ionic polymer-metal composites (ipmcs) as biomimetic sensors, actuators and artificial muscles - a review. Smart Materials and Structures 7, 6, p. R15. 

Shahinpoor, M. and Kim, K. J. (2000). The effect of surface-electrode resistance on the performance of ionic polymer-metal composite (IPMC) artificial muscles, Smart Materials and Structures 9, pp. 543-551. 

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