This paper presents the results of a series of experiments designed to measure the suitability of selected dielectric elastomers as artificial muscle actuators. The paper aims to differentiate between three widely used dielectric elastomers, 3M VHB-4910, BJB Enterprises TC-5005 and NuSil Technology’s CF19-2186. The materials are compared in terms of their ease of manufacture, strain, electrical...

Dielectric elastomers represent today excellent materials for the realisation of electric field driven polymer actuators capable of high performances. A new kind of actuator made of dielectric elastomers, able to show in principle electrically activated linear contractions, is here theoretically described. The device consists of an elastomeric hollow cylinder, having two helical electrodes inte...

Dense rubbery networks are highly entangled polymer systems, with significant topological restrictions for the mobility of neighbouring chains and crosslinks preventing the reptation constraint release. In a mean field approach, entanglements are treated within the famous reptation approach, since they effectively confine each individual chain in a tube-like geometry. We apply the classical ide...

In liquid-crystalline elastomers, the nematic order parameter and the induced strain vary smoothly across the isotropic-nematic transition, without the expected first-order discontinuity. To investigate this smooth variation, we measure the strain as a function of temperature over a range of applied stress, for elastomers cross-linked in the nematic and isotropic phases, and analyze the results...

background and aims. several products have been marketed for disinfecting impression materials. the present study evaluated the effect of deconex, micro 10, alprocid and unisepta plus sprays on staphylococcus aureus and candida albicans transferred to alginate and polyvinylsiloxane impression materials. materials and methods. a total of 180 impressions of a maxillary model (90 alginate and 90 p...

We investigate the soft elastic modes of smectic elastomers, that is shape change without energy cost. We use a microscopic model for their nonlinear elasticity, similar to those used for nematic elastomers. We consider two different phases of smectic elastomer; the biaxial smectic A for a simple illustration, and smectic C phases which are of great practical significance. We show that only one...

Medical-grade silicone elastomers were subjected to accelerated aging in saline to verify the hydrolytic stability of the elastomer. Tensile strength, elongation at break, and the elastomer stress measured at 100% or 200% elongation did not change significantly for peroxide-cured sheeting aged in 37 degrees C or 100 degrees C saline for 45 h. Under similar condition, hydrosilylation cured sheet...

Patterning techniques that rely on high-resolution elastomeric elements such as stamps, molds, and conformable photomasks are operationally simple methods for nanofabrication that may find applications in areas such as molecular and organic electronics. The resolution of these "soft" lithographic procedures is often limited by the mechanical properties of the elastomers. We introduce here a che...

When liquid crystal elastomers are prepared without any alignment, disordered polydomain structures emerge as the materials are cooled into the nematic phase. These polydomain structures are often attributed to quenched disorder in the cross-linked polymer network. As an alternative explanation, we develop a theory for the dynamics of the isotropic-nematic transition in liquid crystal elastomer...

Within the past decade, researchers in the field of tissue engineering have recognized the need for newmaterials with soft and elastic properties. As a result, many groups have focused on the synthesis, characterization, and application of materials with a wide range of biodegradable and elastomeric properties.1 The combination of these polymers with Micro–Electro–Mechanical Systems (MEMS) tech...