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

Abstract

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.

A Non-Linear Dynamic Model of Ionic Polymer-Metal Composite (IPMC) Cantilever Actuator

“…The tip deflections data are taken for 30 seconds for each input voltage. It is observed that system exhibits a typical nonlinear behavior as various non-linear terms are present in the temporal equation of motion (10).…”

“…The observation reveals that with AC input, the actuator can operate for a longer time period than same DC input voltage. The relationship between dehydration of water molecules form IPMC strip (lossfactor) in terms of input voltage (V) and time period (t) as given by [10] and can be represented by Eq. (3) is shown in Figure 3.…”

“… is the fundamental frequency of the system. Substituting equation (8) and (9) in equation 7the resulting non-dimensional temporal equation of motion is obtained by applying the generalized Galerkin's method and can be expressed as: (10) The non-linear temporal equation 10 . Hence, it is observed that the temporal equation of motion (10) contains many nonlinear terms and it is very difficult to obtain the exact solution.…”

“…Nonlinearity in IPMC is caused due to loss of solvent (water) particles in open environment working condition [9]. An analytical model has been proposed to find out the effect of solvent (water) loss on the vibration characteristics of silver-electrode IPMC actuator [10,11]. Considering large bending deformation a nonlinear dynamic model of IPCNC actuators has been proposed using finite element method [12].…”

Investigation on the Mechanical and Electrical Behavior of a Tuning Fork-Shaped Ionic Polymer Metal Composite Actuator with a Continuous Water Supply Mechanism

“…Studies have shown the concentration, intrinsic properties, and moving directions of cations have a dominant effect on the behaviour of the IPMC actuator. Besides, the dynamic motion of IPMC could be a function of driving voltage amplitude, frequency, and device geometry, thereby adding the complication of its performance investigation [ 17 , 18 , 19 ].…”