Dillip Kumar Biswal

Dynamic Modeling and Effect of Dehydration on Segmented IPMC Actuators Following Variable Parameter Pseudo-Rigid Body Modeling Technique

An ionic polymer-metal composite actuator has been analyzed following the variable parameters pseudo-rigid body modeling (VPPRBM) technique in order to assess the effect of dehydration on bending resistance and bending response. An experiment is conducted with a single patch IPMC actuator and the dehydration factor is obtained following the Cobb-Douglas production method. An energy-based dynamic model of the patches has been derived after developing the forward kinematics incorporating loss due to dehydration. Simulation has been performed for two segmented IPMC patches to demonstrate the change in bending resistance, bending response, and end-tip positioning for various input voltages.

Investigation and evaluation of effect of dehydration on vibration characteristics of silver-electroded ionic polymer–metal composite actuator

Theoretical and experimental investigation of dehydration loss of ionic polymer–metal composite actuator is important to evaluate the stability, accuracy, and effectiveness of actuation. An ionic polymer–metal composite actuator of silver electrode has been analyzed to demonstrate the effect of dehydration on vibration characteristics during actuation. Experiment is conducted in cantilever configuration under direct current potential, and the bending and vibration characteristics are measured by Laser Vibrometer. As dehydration occurs during the actuation process, these experimental data are used to establish empirical model for loss-factor in terms of input voltage and time using Cobb–Douglas production method. A correlation is also developed for tip deflection with applied voltage. For theoretical investigation, multimode approximation has been taken into consideration and extended Hamilton’s principle is applied for developing the governing equation of motion of the actuator. Few modes are taken into consideration, and the equations are solved numerically to obtain the transient and steady-state responses of the actuator. Theoretical steady-state results are compared and validated with the experimental results. Both theoretical and experimental results show the gradual reduction of tip displacement due to dehydration.

Electro-mechanical and thermal characteristics of silver-electroded ionic polymer–metal composite actuator

The proposed work is in line with the evaluation of electro-mechanical and thermal characteristics of silver-electroded ionic polymer–metal composite (IPMC). IPMCs are fabricated first using Nafion-117 as base polymer and non-precious metal silver as surface electrode by chemical decomposition method. Several testings are performed on fabricated IPMC to evaluate its thermo-mechanical and micro-structural properties. The characteristics of the electrode layer and deposited particles on IPMC surface are studied using scanning electron microscope. The bending experiment of the actuator is conducted by applying direct current potential and the tip displacement measured. Thermo-gravimetric analysis and differential scanning calorimetry test are carried out, and thermal stability of the actuator is investigated. The crystal structure of IPMC is investigated by X-ray diffraction analysis. Micro-tensile test of the specimen is carried out to ascertain the stress–strain relationship and comparison is made with the base polymer, Nafion. The experimental investigations, characterization, and performance of the IPMC demonstrate its effectiveness to be used as actuator and artificial muscle materials.

Fabrication and Thermo-Mechanical Analysis of Pure Silver-Electrode Ionic Polymer-Metal Composite (IPMC) Actuator

Till to date, fabrication of Ionic Polymer-Metal Composites (IPMC) are carried out successfully using noble metal such as platinum/gold as the surface electrode. In this work we have proposed cost effective fabrication method for IPMC actuator using non-precious metal electrode of silver (Ag). Chemical decomposition method is followed using Nafion as the ion exchange membrane to fabricate pure Ag-electrode IPMC. Microscopic and morphological analyses reveal that, silver particles penetrate well through the surface of Nafion membrane. The bending deformation measurement and analysis of the thermo-mechanical properties of the fabricated IPMC is carried out. The experiment results and performance of the IPMC actuator confirm that the fabrication of pure Ag-IPMC is feasible and can be used as artificial muscle material.

Evaluation of dehydration loss and investigation of its effect on bending response of segmented IPMC actuators

Efforts were made to estimate and analyze the effect of dehydration on the bending response of segmented ionic polymer–metal composite (IPMC) actuators. An experiment was conducted with an IPMC actuator to study the variation of bending characteristics with input voltage. Based on the experimental data, the Cobb–Douglas production method was used to obtain the dehydration factor in terms of input voltage and time. The motion of the patches was restricted to planar in two dimensions. A single-patch IPMC actuator was then modeled following the Euler–Bernoulli approach incorporating loss due to dehydration. A forward kinematics model for the segmented actuators was formulated after constituting the homogeneous coordinate transformation matrix, assuming it is a serial link multi-degree of freedom manipulator. An energy-based dynamic model of the patches was derived using the Lagrange principle. Simulations were performed for single and two segmented IPMC patches to demonstrate the bending response for various input voltages. The results demonstrate the gradual reduction of bending response of an actuator owing to moisture loss.

Evaluation of Electromechanical, Damping and Dynamic Mechanical Properties of Silver Electrode IPMC Actuator

Polymeric artificial muscle technologies are being developed that can produce similar strains and higher stresses like natural muscles using electro-static forces, electro-striation, ion interaction, and molecular conformational changes. Of specific interest, Ionic Polymer Metal Composite (IPMC), a class of polymer labeled as electroactive polymer (EAP) is being considered in application both as sensor and actuator. The proposed work is in line with the characterization of inexpensive IPMC of non-precious metal silver as the surface-electrode. At first, IPMCs are fabricated following chemical decomposition method. Several experiments are conducted for evaluation of surface resistance, damping properties, solvent loss, dynamic mechanical properties, tip displacement, and tip force to investigate the performance of the IPMC actuator. The experimental results suggest that the low cost Ag-IPMC is suitable for application as an active actuator.