Ionic Polymer Metal Composites (IPMCs) are electro-responsive materials for sensing and actuation, consisting of an ion-exchange polymeric membrane with ionized units, plated within noble metal electrodes. In this work, we investigate the sensing response of IPMCs that are subject to a through-the-thickness compression, by specializing the continuum model introduced by Cha and Porfiri,1 to this one-dimensional problem. This model modifies the classical Poisson-Nernst-Plank system governing the electrochemistry in the absence of mechanical effects, by accounting for finite deformations underlying the actuation and sensing processes. With the aim of accurately describing the IPMC dynamic compressive behavior, we introduce a spatial asymmetry in the properties of the membrane, which must be accounted for to trigger a sensing response. Then, we determine an analytical solution by applying the singular perturbation theory, and in particular the method of matched asymptotic expansions. This solution shows a good agreement with experimental findings reported in literature.
In this paper, we investigate the feasibility of energy harvesting from the mouse click motion using a piezoelectric
energy transducer. Specifically, we use a robotic finger to realize repeatable mouse click motion. The robotic
finger wears a glove with a pocket for including the piezoelectric material as an energy transducer. We propose
a model for the energy harvesting system through the inverse kinematic framework of parallel joints in the
finger and the electromechanical coupling equations of the piezoelectric material. Experiments are performed to
elucidate the effect of the load resistance and the mouse click motion on energy harvesting.
In this paper, we investigate the feasibility of energy harvesting from axisymmetric vibrations of annular ionic polymer metal composites (IPMCs). We consider an in-house fabricated IPMC that is clamped at its inner radius to a moving base and is free at its outer radius. We propose a physics-based model for energy harvesting from underwater vibrations, in which the IPMC is described as a thin annular plate undergoing axisymmetric vibrations with an added mass due to the encompassing fluid. Experiments are performed to elucidate the effect of the shunting resistance and the excitation frequency on energy harvesting.
In this paper, we propose a novel modeling framework to study quasi-static large deformations and electrochemistry of ionic polymer metal composites (IPMCs). The chemoelectromechanical constitutive behavior is obtained from a Helmholtz free energy density, which accounts for mechanical stretching, ion mixing, and electric polarization. The framework is specialized to plane bending of thin IPMCs through a structural model, where the bending moment of the IPMC is computed from a one-dimensional modified Poisson-Nernst-Planck system. For small static deformations, we establish a semianalytical solution based on the method of matched asymptotic expansions, which we ultimately use to elucidate the physics of IPMC sensing and actuation.
In this paper, we study the charge dynamics of ionic polymer metal composites (IPMCs) in response to an
imposed time-varying flexural deformation. IPMC chemoelectromechanical behavior is described through the
Poisson-Nernst-Planck framework, and the method of matched asymptotic expansions is utilized to establish a
closed-form solution for the electric potential and counterion concentration in the IPMC. This solution is, in
turn, leveraged to derive a mathematically tractable distributed circuit model of IPMC sensing.
In this paper, we analyze buckling of an ionic polymer metal composite (IPMC) shell subjected to uniaxial
compression. A new technique is developed to fabricate tubular IPMCs using hot molding and a chemical
reduction process. The short-circuit current and the mechanical deformation of the sample are recorded during
the compression test. Experimental findings demonstrate that IPMC buckling can be accurately sensed via the
short-circuit current, which is approximately zero during the loading phase, before exhibiting a sudden increase
at the onset of the elastic instability.
This study seeks to investigate the feasibility of energy harvesting from mechanical buckling of ionic polymer metal composites (IPMCs) induced by a steady ﬂuid ﬂow. In particular, we propose a harvesting device composed of a paddle wheel, a slider-crank mechanism, and two IPMCs clamped at both their ends. We test the system in a water tunnel to estimate the eﬀects of the ﬂow speed and the shunting resistance on power harvesting. The classical post-buckling theory of inextensible rods is utilized, in conjunction with a black-box model for IPMC sensing, to interpret experimental results.
In this paper, we analyze the charge dynamics of ionic polymer metal composites (IPMCs) in response to voltage inputs composed of a DC bias and a small AC voltage. IPMC chemoelectrical behavior is described through the Poisson-Nernst-Planck framework. The physics of charge build up and mass transfer at the electrodes are modeled through metal particle layers. Perturbation methods are used to establish an equivalent circuit model for the IPMC electrical response. The proposed approach is validated through comparison with finite element results.