On the design of large degree-of-freedom digital mechatronic devices based on bistable dielectric elastomer actuators

Abstract

Abstract-Binary actuation has been proposed to reduce complexity in robotic and mechatronic systems. However, a relatively large number of binary actuators are required to achieve the accuracy necessary for practical applications. Conventional actuators are not practical for such large degree-of-freedom (DoF) devices. Here, a dielectric elastomer (DE) actuator is developed for these applications. It is shown that DE actuators have high energy densities, light weight, low cost, and large displacements. Hence they could potentially make large DoF binary systems practical. DE actuators proposed here consist of thin electrically sensitive elastomer films that are mounted in a flexible frame that incorporates a passive bistable element. The frame prestrains the film and provides a restoring force that allows the actuator to operate bidirectionally. A simple experimental prototype 6-DoF binary manipulator demonstrates the concept.Index Terms-Binary actuation, bistable mechanism design, hyperredundant manipulator, polymer actuators.

Nonlinear electroelasticity: material properties, continuum theory and applications

“…Here, we mention just a small selection of subsequent works involving different geometries. In adopting silicone elastomers as materials for actuators, the effects of pre-strain, hardener concentration and dielectric filler were investigated by Zhang et al [62] for both planar and spring-roll actuators, while a variable geometry hexagonal frame design for pre-straining dielectric actuators with several degrees of freedom was used by Wingert et al [63]. Kofod et al [64] investigated the formation of complex out-of-plane electroelastic structures for use as claws in robotic gripping technology.…”

Materials and Textile Architecture Analyses for Mechanical Counter-Pressure Space Suits using Active Materials

“…For this reason, DEAs hold significant promise as artificial muscles or other robotic actuators [40][41][42] . Because DEAs produce expansion strains that are orders of magnitude larger than those of other active materials, as an individual element they could provide significant shape change ability to a compression garment when integrated circumferentially.…”

On the Kinematics of Solar Mirrors Using Massively Parallel Binary Actuation

“…The equations can be manipulated into the matrix form:  y Ad (8) where y is a vector of beam displacements at the actuator locations and d is a vector of ones and zeros defining which actuators are extended (1) and which actuators are contracted (0). Equations (2) and (3) can be used to determine the beam deflection and slope at any point.…”

“…In the past, conventional elements, such as pneumatic pistons and solenoids, have been used to drive bi-stable mechanisms. Recent studies have shown the potential of using simple, lightweight, low-cost dielectric elastomer actuators (DEA) to activate bi-stable mechanisms [8,9]. Researchers have studied the use of these binary actuators in serial robotic manipulators [10][11][12][13][14].…”