Jinxiong Zhou's blog

A cantilever beam with elastic hinge pulled antagonistically by two dielectric elastomer (DE) membranes in tension forms a foldable actuator if one DE membrane is subject to a voltage and releases part of tension. Simply placing parallel rigid bars on the prestressed DE membranes results in enhanced actuators working in pure shear state. We report design, analysis, fabrication and experiment of soft mobile robots that are moved by such foldable DE actuators.

Combining
soft active hydrogels with hard passive polymers gives rise to all-polymer
composites. The hydrogel is sensitive to external stimuli while the passive
polymer is inert. Utilizing the different behaviors of two materials subject to
environmental variation, for example temperature, results in self-folding soft
machines. We report our efforts to model the programmable deformation of
self-folding structures with temperature-sensitive hydrogels. The self-folding
structures are realized either by constructing a bilayer structure or by
incorporating hydrogels as hinges. The methodology and the results may aid the

When an electric voltage is applied across the thickness of a thin layer of an dielectric elastomer, the layer reduces its thickness and expands its area. This electrically induced deformation can be rapid and large, and is potentially useful as soft actuators in diverse technologies. Recent experimental and theoretical studies have shown that, when the voltage exceeds some critical value, the homogenous deformation of the layer becomes unstable, and the layer deforms into a mixture of thin and thick regions.

A subdomain collocation method based on Voronoi diagrams and reproducing kernel approximation is presented. The unkonwn field variables are approximated via reproducing kernel approximation. The body integration arising from the numerical evaluation of Galerkin weak form is converted into much cheaper contour integration along the boundary of each Voronoi cell. The Voronoi cells also provide an natural structure to perform h-adaptivity.