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.