Active polymers/gels

This chapter was adapted from in part, by permission, M. Otake, M. Inaba and H. Inoue, Kinematics of Gel Robots made of Electro-Active Polymer PAMPS Gel , Proceedings of IEEE International Conference on Robotics and Automation, pp.488-493, 2000 M. Otake, Y. Kagami, M. Inaba, and H. Inoue, Dynamics of Gel Robots made of Electro-Active Polymer Gel , Proceedings of IEEE International Conference on Robotics and Automation, pp. 1458-1462, 2001 M. Otake, Y. Nakamura, and H. Inoue, Pattern Formation Theory for Electroactive Polymer Gel Robots , Proceedings of IEEE International Conference on Robotics and Automation, pp.2782-2787, 2004. 

In this section, it was shown that a method to solve inverse kinematics of gel robots made of electro-active polymer gel. As a first step, a method was proposed to control the tip position of a manipulator entirely made of electro-active... 

Electro-active polymer gels as artificial muscles... 

From electro-active polymer gel to electro-active elastomer with large deformation... 

Dehydration or Chemical Stabilization. The removal of surface silanol (Si—OH) bonds from the pore network results in a chemically stable ultraporous soHd (step F, Fig. 1). Porous gel—siHca made in this manner by method 3 is optically transparent, having both interconnected porosity and sufficient strength to be used as unique optical components when impregnated with optically active polymers, such as fiuors, wavelength shifters, dyes, or nonlinear polymers (3,23). 

By coating the compliant electrodes with a thicker but softer layer of polymer gel, the gel can spread out along with the expanding fihn during actuation but bunches at points where the film compresses. If the polymers are imprinted with patterns of electrodes or shades of dots in a variety of shapes, these features can be raised or lowered to fabricate an active camouflage fabric which can change its reflectance for any defence systems and soldiers. 

All copolymers were prepared by solution polymerization, under adiabatic conditions, giving at least 99.9% conversions. The polymer gels were granulated and then dried at 90 °C to a residual water content of 10 to 12%. The active polymer content of each sample was calculated from the initial weight of the comonomers and the weight of the dried gel. Hydrolysis of the polymers was determined by conductometric titration to be less than 0.2% of the acrylamide charge. The molecular weight of the polymers was 8-10 million as determined by intrinsic viscosity measurements. 

Sounds and vibrations in electrical appliances or vehicles are in some cases unpleasant. If we can reduce these sounds and vibrations as we desire, we will have a more happy and comfortable life in the next century. Sections 4 and 5 discuss a new smart polymer gel for actively reducing sounds and vibrations. The smart gel can vary its elastic modulus in an electric field. 

The model of electric field-controlled artificial muscles has been described in 1972 [5], Fragala et al. fabricated an electrically activated artificial muscle system which uses a weakly acidic contractile polymer gel sensitive to pH changes. The pH changes are produced through electrodialysis of a solution. The response of the muscle as a function of pH, solution concentration, compartment size, certain cations, and gel fabrication has been studied. The relative change in length was about 10%, and the tensile force was 1 g/0.0025 cm2 under an applied electric field of 1.8 V and 10 mA/cm2. It took 10 min for the gel to shrink. 

Poly(oxyethylene)-Si02 ormosils have been prepared as an approach to the preparation of biologically active polymer-apatite composites. For this purpose, Yamamoto et al. [72] obtained these Class II hybrids from triethoxysilyl-terminated poly(oxyethylene) (PEG) and TEOS by using the in situ sol-gel process. After being subjected to the biomimetic process to form the bone-like apatite layer, it was found that a dense apatite layer could be prepared on the hybrid materials, indicating that the silanol groups provide effective sites for CHA nucleation and growth. 

It should be noted that the activation energies for motional processes in the same crosslinked polymer gel calculated from line widths in 13C NMR spectra are higher than those calculated from 1H NMR spectra under the magic angle conditions (residual line width). These findings indicate that 13C line widths (which are of the order of 10 Hz) are probably more affected by sample inhomogeneity and by relatively small residual chemical shift anisotropies 162). 

Phase transition in gels in response to biochemical reactions [27,28]. Polymer gels were synthesized in which an enzyme (urease) or a biologically active protein (lectin) was immobilized. The volume phase transitions were observed in such gels when biochemical reactions took place. Such mechano-biochemical gels will be used in devices such as, sensors, selective absorbers, and biochemically controlled drug release. 

The synthesis of optically active polymers is an important area in macromolecular science, as they have a wide variety of potential applications, including the preparation of CSPs [31-37]. Many of the optically active polymers with or without binding to silica gel were used as CSPs and commercialized [38]. These synthetic polymers are classified into three groups according to the methods of polymerization (1) addition polymers, including vinyl, aldehyde, isocyanide, and acetylene polymers, (2) condensation polymers consisting of polyamides and polyurethanes, and (3) cross-linked gels (template polymerization). The art of the chiral resolution on these polymer-based CSPs is described herein. 

Hirai T., Zheng J., Watanabe M., Electrically active polymer materials - application of non-ionic polymer gel and elastomers for artificial muscles in Tao X. (ed.) Smart Fibres, Fabrics and Clothing, Woodhead Publishing, Cambridge. 2001. 

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