TY - GEN
T1 - On structural models for ionic polymer metal composites (SPIE Best Student Paper Finalist)
AU - Boldini, Alain
AU - Bardella, Lorenzo
AU - Porfiri, Maurizio
N1 - Funding Information:
This research was supported by the National Science Foundation under Grant No. OISE-1545857.
Publisher Copyright:
© 2020 SPIE.
PY - 2020
Y1 - 2020
N2 - Ionic polymer metal composites (IPMCs) are a class of soft electroactive polymers. IPMCs comprise a soft ionic polymer core, on which two stiff metal electrodes are plated. These active materials exhibit large bend-ing upon the application of a small driving voltage across their electrodes, in air or in aqueous environments. In a recent work, we presented compelling theoretical and numerical evidence suggesting that ionic polymer membranes exhibit complex multiaxial deformations neglected by reduced-order structural models. Where most beam theories (including Euler-Bernoulli, Timoshenko, and most higher-order shear deformation models) would suggest vanishing through-The-Thickness deformation, we discover the onset of localized deformation that rever-berates into axial stretching. Building upon this effort, here we investigate the role of the electrodes and shear on multiaxial deformations of IPMCs. We establish a novel structural theory for IPMCs, based on the Euler-Bernoulli kinematics enriched with the through-The-Thickness deformation in the ionic polymer, computed from a Saint-Venant-like problem for uniform bending. While considering boundary conditions that elicit non-uniform bending, we compare the results of this model against classical Euler-Bernoulli beam theory without enrichment and finite element simulations, encapsulating the nonlinear response of the material. We demonstrate that our theory can predict the macroscopic displacement of the IPMC, along with the localized deformation in the ionic polymer at the interface with the electrodes, which are not captured by the classical Euler-Bernoulli beam theory. This work paves the way to the development of more sophisticated structural theories for IPMCs and analogous active materials, affording an accurate description of deformations at a limited computational cost.
AB - Ionic polymer metal composites (IPMCs) are a class of soft electroactive polymers. IPMCs comprise a soft ionic polymer core, on which two stiff metal electrodes are plated. These active materials exhibit large bend-ing upon the application of a small driving voltage across their electrodes, in air or in aqueous environments. In a recent work, we presented compelling theoretical and numerical evidence suggesting that ionic polymer membranes exhibit complex multiaxial deformations neglected by reduced-order structural models. Where most beam theories (including Euler-Bernoulli, Timoshenko, and most higher-order shear deformation models) would suggest vanishing through-The-Thickness deformation, we discover the onset of localized deformation that rever-berates into axial stretching. Building upon this effort, here we investigate the role of the electrodes and shear on multiaxial deformations of IPMCs. We establish a novel structural theory for IPMCs, based on the Euler-Bernoulli kinematics enriched with the through-The-Thickness deformation in the ionic polymer, computed from a Saint-Venant-like problem for uniform bending. While considering boundary conditions that elicit non-uniform bending, we compare the results of this model against classical Euler-Bernoulli beam theory without enrichment and finite element simulations, encapsulating the nonlinear response of the material. We demonstrate that our theory can predict the macroscopic displacement of the IPMC, along with the localized deformation in the ionic polymer at the interface with the electrodes, which are not captured by the classical Euler-Bernoulli beam theory. This work paves the way to the development of more sophisticated structural theories for IPMCs and analogous active materials, affording an accurate description of deformations at a limited computational cost.
KW - beam theories
KW - electrochemistry
KW - non-uniform bending
KW - reduced-order modeling
KW - through-The-Thickness deformation
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U2 - 10.1117/12.2558302
DO - 10.1117/12.2558302
M3 - Conference contribution
AN - SCOPUS:85085584576
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Electroactive Polymer Actuators and Devices (EAPAD) XXII
A2 - Bar-Cohen, Yoseph
A2 - Anderson, Iain A.
A2 - Shea, Herbert R.
PB - SPIE
T2 - Electroactive Polymer Actuators and Devices (EAPAD) XXII 2020
Y2 - 27 April 2020 through 8 May 2020
ER -