Dear Colleagues,
We would like to to draw your attention to the Symposium on **Soft Materials and Structures** to take place at the upcoming 49th Meeting of the Society of Engineering Sciences (SES) at GeorgiaTech, Atlanta, GA (October 10-12, 2011). More information can be found in the meeting's website: http://ses2012.org/
Choon Chiang Foo, Shengqiang Cai, Soo Jin Adrian Koh, Siegfried Bauer, Zhigang Suo.
Model of dissipative dielectric elastomers.
Journal of Applied Physics 111, 034102 (2012).
Abstract
The dielectric constant of elastomeric dielectric material is an
essential physical parameter, whose value may affect the
electromechanical deformation of a dielectric elastomer actuator. Since
the dielectric constant is influenced by several external factors as
reported before, and no certain value has been confirmed to our
knowledge, in the present paper, on the basis of systematical comparison
of recent past literature, we conducted extensive works on the
measurement of dielectric properties of VHB films, involving five
influencing factors: prestretch (both equal and unequal biaxial),
electrical frequency, electrode material, stress relaxation time and
temperature. Experimental results directly show that the dielectric
What is the reason behind the nonlinearity in the stress-strain curve of elastomers(Molecular Level)
For a dielectric elastomer membrane we show giant voltage-triggered expansion of area by 1692%, far beyond the largest values reported in the literature.
Abstract:A hydrostatically coupled dielectric elastomer (HCDE) actuator consists of two membranes of a dielectric elastomer, clamped with rigid circular rings. Confined between the membranes is a fixed volume of a fluid, which couples the movements of the two membranes when a voltage or a force is applied. This paper presents a computational model of the actuator, assuming that the membranes are neo-Hookean, capable of large and axisymmetric deformation. The voltage-induced deformation is described by the model of ideal dielectric elastomer. The forc
Dielectric elastomer (DE) is a kind of electroactive polymer material,
capable of large deformation up to 380%. However, under conservative
operating conditions, DE is susceptible to instability with a small
deformation due to various modes of failure, including electrical
breakdown, electromechanical instability (EMI), loss of tension and
rupture by stretch. This paper proposes a free energy model in the
thermodynamic system of DE involving thermoelastic strain energy,
electric energy and purely thermal contribution energy to obtain the
stability conditions of all failure modes. The numerical results
indicate that the increase in temperature can markedly contribute to
improving the entropy production, the actuation stress and the critical
