Japanese Scientists invented “elastic water”, paving the way for ecologically clean plastic materials
According to the Japan Science and Technology Agency (JST), Japanese Scientists invented “Elastic Water”.
Bo Li's blog
Dielectric strength: dependent or independent of stretch？
Dielectric elastomer can undergo giant deformation, but are susceptive to various failure modes. i.e electrical breakdown.
Some experimental papers (Kofod, Plante, Chen, see the attachment) reported the dielectric strength of VHB material (a kind of dielectric elastomer) under difference pre-stretch, equal bi-axially or unequal bi-axially. And the strength (maximum voltage can be applied before breakdown) has be greatly improved by these mechanical stretches.
So here comes the question: is the dielectric strength dependent or independent of stretch？
How is the entropy of polarization in dielectric material
In the study of thermoelastic actuation of dielectric elastomer, we can write the Helmholtz free-energy as a function of stretch ratio, nominal electric displacement and temperature (T).
The entropy (S) is the negative partial differential coefficient of W with respect of temperature (T). And we can see the change of S is due to three components: deformation, heat conduction and polarization. In an isothermal state, the deformation part has been fully investigated by Arruda and Boyce in 1993, but the polarization-induced entropy (Sp) has not been clearly stated.