Analysis, experiment, and correlation of a petal-shaped actuator based on dielectric elastomer minimum-energy structures

Abstract

Releasing a bimaterial system, which consists of a pre-stretched dielectric elastomer membrane attached on a flexible frame, transforms a planar structure into a 3D structure through buckling. The buckled structure can deform further upon applying of a voltage, giving rise to the so-called dielectric elastomer minimum-energy structures (DEMES). Simple and easy-to-use theory and model would simplify the tedious trial-and-error designing process. We describe an extended model accounting for nonlinear rubber elasticity, pre-stretch, and the concentrated transverse load of a bending beam DEMES actuator. We design and fabricate a petal-shaped actuator with three petals. Elevation of a 1-g mass upward 7 mm is demonstrated upon application of 7000 V. Good correlation is achieved between model prediction and experimental measurement.

Designing Soft Mobile Machines Enabled by Dielectric Elastomer Minimum Energy Structures

“…Among these, the dielectric elastomer minimum energy structures (DEMES) actuators have attributed great attention due to their ease of fabrication, simplicity in working principles, and wonderful extensible property [ 22 , 23 ]. DEMES thus have been developed for single or multiple-segment grippers, petal-like actuators, oscillators, and mechanical translational mechanisms [ 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. Meanwhile, the Euler-Lagrange energy method was used to study the nonlinear dynamic behavior of DEMES, and the results show that DEMES systems possess harmonic resonances and superharmonic and subharmonic resonances [ 29 ].…”

Design method of DEMES rotary joint

“…Compared with the popular materials for soft actuators such as shape memory alloy actuators (SMA), shape memory polymer actuators (SMP), and ionic polymer metal composites actuators (IPMC), dielectric elastomers (DE) have a faster response [1], larger strain deformation [2], higher energy densities [3] and simpler fabrication [4]. So dielectric elastomers have been widely used for soft actuators and soft sensors [27][28][29][30][31][32][33][34][35][36][37][38]. The dielectric elastomer minimum energy structure (DEMES) [9,10] is a kind of soft actuator that can transform planar area expansion of the DE film into complex three-dimensional (3D) shapes determined by a configuration that minimizes the elastic energy of the DE film and the bending energy of the primary frame (see figure 1).…”

A method to increase the dynamic deformation of a dielectric elastomer minimum energy structures rotary joint without increase of the voltage amplitude

“…Moreover, DEMES can transform the linear strain of a DE film to an angular deformation of a frame, and a large angular deformation can be realized by only a small linear strain. It has therefore attracted much attention to its theory and applications (Buchberger et al, 2013;Gisby et al, 2012;Liu et al, 2016;O'Brien et al, 2009;Rhode-Barbarigos et al, 2014;Rosset et al, 2014;Shintake et al, 2015aShintake et al, , 2015bZhao et al, 2015aZhao et al, , 2015bZhao et al, , 2015cZhao et al, , 2016aZhao et al, , 2016b.…”