Strong dielectric-elastomer grippers with tension arch flexures

Abstract

Soft grippers based on dielectric elastomer actuator (DEA) are usually too flimsy to perform the task of pick and place on a heavier object given their low payload capacity. This work developed a new design of DEA unimorph consists of a flexible frame holding at a DEA on the discrete support by a stiffer spine-like flexure of 380µm thick Polyvinyl chloride (PVC) sheet. It finds an equilibrium of curling up when the DEA's pre-stretch is partially released; it can electrically unfolds upon a voltage application. This dielectric elastomer unimorph of 3 grams produced a maximum voltage induced bending of close to 90 • and a maximum voltage-induced blocked force of up to 168mN. Given their higher stiffness and large actuation, these 3-D shaped and strengthened DEA unimorphs can make stronger grippers for passive grasping and active pinching.

Soft dielectric actuator produced by multi‐material fused filament fabrication 3D printing

“…This work O'Brien et al 22 Araromi et al 34 Heng et al 35 Zhou et al As a drawback, attributable to the low electrical conductivity of the electrode material, the response time of the actuators was rather high. Enhancing the electrical conductivity of the electrode material would reduce the response time of these actuators.…”

Dielectric Elastomer Actuator for Soft Robotics Applications and Challenges

“…Although the gripping force is not sufficient, this design could be recognized as a milestone for developing DE grippers. Multi-segment DEMES with an arch-structured flexible frame was developed to achieve a higher grasping capability, as shown in Figure 7d [88]. The pre-stretched DE with the arch-structured frame can generate a higher bending moment than with a flat frame, due to the increased distance between the pre-stretched DE and neutral axis [89].…”

Versatile Ultrasoft Electromagnetic Actuators with Integrated Strain‐Sensing Cellulose Nanofibril Foams

“…Soft robots can be integrated into flexible and deformable systems, thereby enabling the performance of a variety of tasks in a lifelike, adapting, and interacting manner. [5] Actuation is one of the most challenging aspects of soft robotics, and a variety of approaches have been explored, including pressure-driven actuation, [6,7] thermal actuation, [8,9] humiditydriven actuation, [10][11][12][13] dielectric elastomer actuation, [14][15][16] and electromagnetic actuation. [17][18][19][20][21][22][23][24][25][26][27][28] Pressure-driven actuators can generate large forces and deformations but have slow response and require relatively high-pressure equipment to function.…”

“…[10][11][12][13] In contrast, dielectric elastomer actuators offer fast response, high force, and a large stroke length, but require high voltages in the kV range to operate, which constitute a serious health hazard. [14][15][16] Electromagnetic actuators are promising for soft robotic applications due to their fast response, low driving voltage, and ease of control. However, most soft electromagnetic actuators require large external magnets [19][20][21][22][23] or strong external magnetic fields [24] to operate.…”