Towards Understanding How to Design a Soft Artificial Muscle Actuator?

<br>In this manuscript we present a physics based model for sake of understanding<br>the actuation mechanism and the desired blocked force generated with respect<br>to the applied potential field at different geometries.<br>In the experimental work, we have found that the frequency and the am-<br>plitude plays a crucial role in actuation profile of ionic EAP. For estimating<br>the blocked force generated along the spatial domain of ionic EAP, we have<br>implemented Coulomb inverse square law as there is an electrostatic interaction<br>among one mobile ion and N of elementary electric charge which could be re-<br>pulsion or attraction on both surface area of ionic EAP based on the applied<br>potential field phase.<br>The ionic EAP is a tri-layer, assuming that the upper and lower layer which<br>are conductive layer a RC transmission line where we assume that R is constant<br>for sake of simplicity. The potential field at the clamping point is diffused along<br>the muscle, one dimensional diffusion model is implemented for estimating the<br>elementary electric charges diffused in the surface area of the upper layer. As<br>ionic EAP is working as mutual capacitor, we have assumed that the charges<br>of the stored mobile ions in the medium layer has the same initial value of the<br>elementary electric charges in the upper and conductive layer.<br>After estimating the spatial charge of the electrons and ions, the stress-<br>charge coupling is multiplied with the estimated value for having the value of<br>stress, force, strain, and curvature which is important for designing coupled<br>actuators.<br>Following, we have simulated forward and inverse approaches for estimating<br>the force and the desired potential field in each case for a coupled actuators.<br>The stress charge coupling can estimate the steady state final value of the<br>generated force, however, it doesnot capture the stress relaxation behavior or<br>saturation phenomena occurs during the low frequency. We believe that under-<br>standing the physics behind the actuation of ionic EAP artificial muscle could<br>lead us to design a desired artificial muscle for specific application and improving<br>their mechanical properties and response time as well.<br>1