A lumped parameter model for strip-shaped dielectric elastomer membrane transducers with arbitrary aspect ratio

Abstract

Dielectric elastomer (DE) membrane transducers allow to achieve large strain, low energy consumption, low-noise, and highly compact mechatronic devices. To optimize the design of membrane DEs via numerically efficient software tools, as well as to develop accurate control and self-sensing algorithms, a lumped parameter model is required. In the case of rectangular DE strips clamped at both ends and subject to a uniaxial in-plane load, the resulting necking and inhomogeneous deformation turn out to be challenging to be described via standard lumped models, thus making it necessary to rely on numerically involved finite element (FE) tools. In this paper, we present a novel modeling framework that permits to accurately describe clamped DE membranes with generic aspect ratio in a control-oriented fashion. The model is grounded on an anisotropic free-energy function, which maps the inhomogeneities due to clamping within the constitutive membrane behavior. In this way, a lumped description of the DE can be obtained in terms of average stress and stretch quantities. After presenting the model, an extensive validation is performed by means of comparative studies with FE simulations as well as experimental results. It is observed how the proposed model permits to accurately describe the electro-mechanical response of clamped DE membranes for a wide range of aspect ratios, including nearly-uniaxial, nearly-pure shear, as well as intermediate configurations.

High-frequency voltage-driven vibrations in dielectric elastomer membranes

“…The non-equilibrium stress can be formulated resorting to established visco-elastic models, which make use of a set of additional equations for the internal states dynamics [29]. In the results presented in this work (see Sect.…”

Nanoscale Nickel-Based Thin Films as Highly Conductive Electrodes for Dielectric Elastomer Applications with Extremely High Stretchability up to 200%

“…A length to width ratio of 5/1, with the pulling direction being perpendicular (see Figure 3) to the long side, allows us to interpret the uniaxial tensile test as a pure shear tensile test. 47,48 The colors match the ones of the following result graphs. The pure shear tensile test is carried out with electrodes prestretched under normal conditions, that is, 37.5% biaxially and 57.5% PSC, and with electrodes of the increased level of prestretch (57.5% biaxial and 83% PSC).…”

“…At least four single specimens of each type of electrode, that is, Ni, Ni + C, or C + Ni, are tested in a pure shear uniaxial tensile test. A length to width ratio of 5/1, with the pulling direction being perpendicular (see Figure ) to the long side, allows us to interpret the uniaxial tensile test as a pure shear tensile test. , The pure shear tensile test is carried out with electrodes prestretched under normal conditions, that is, 37.5% biaxially and 57.5% PSC, and with electrodes of the increased level of prestretch (57.5% biaxial and 83% PSC). Every strain level is kept constant for 25 s, while the corresponding resistance is averaged and subsequently plotted versus strain.…”

Design, Manufacturing, and Characterization of Thin, Core-Free, Rolled Dielectric Elastomer Actuators

“…To further investigate the performance and compare the CORDEA to the hollow RDEA, the acquired displacement and force data are normalized. The engineering strain ε 1 , based on the initial roll length L roll,0 and the measured roll length L roll (t), as well as the engineering stress δ 1 (t), based on the measured force and the initial cross-sectional area of the film, are given as follows [32]:…”