Bending Curve Modeling of Ionic Polymer Metal Composites in Soft Actuator Applications

Abstract

Ionic Polymer Metal Composites (IPMC) may be used to replace the electro-mechanical actuators in a vast variety of application areas rangingfrom biomedical devices to soft actuators and sensor systems in modern humanoid robotics. The excellent characteristics shown by IPMCs are highly influenced by their interrelated mechanical, electrical and chemical properties. However, this makes it complicated and difficult to understand the physics and predict their behavior. In order to utilize the full potentials towards advanced engineering, there is an increasing need to investigate their actuation mechanism and derive means of predicting the behavior. The object of this paper is to characterize and model the bending motion of the strip-type IPMC actuators using the theory on large deflections of beams. After deriving a mathematical model approximately accounting for mechanical, electrical, and chemical properties and geometric parameters of the actuator, the model has been experimentally verified for an actuator with the dimensions 25mm x2.6mm x 0.44 mm. Theoretical and experimental results are presented to demonstrate that the model is effective enough to predict the displacement output of the strip type-IPMC actuator all along the edge ofthe actuator as afunction ofthe applied voltage.

Development and modeling of a new ionogel based actuator

“…(5) The resulting strain distribution varies linearly along the thickness of the actuator with respect to the distance from the neutral axis (Alici et al, 2006;Samaranayake et al, 2007), as shown in Figure 10.…”

Dynamic Modeling of Ionic Polymer Metal Composite Using Equivalent Passive Electric Network Components

“…Their inherent light weight, flexibility, repeatability and the tip force have been the major concerns to replace the electro-mechanical actuators in a vast variety of afore mentioned application areas. Many studies have been carried out to develop cost effective fabrication techniques, improve electro-chemo-mechanical characteristics, derive finite element and other modeling techniques, etc [2]. However very little attentions have been paid on the control of IPMCs.…”

“…It is neutralized with the necessary amount of counter-ions such as H+, Li+, Na+, K+ etc, balancing the charge of anions covalently fixed to the backbone membrane. When a thin strip of an IPMC membrane in the hydrated state is stimulated by the application of a step voltage, the composite bends towards the anode [2]. The magnitude and speed of these deflections depend on the nature of the counter-ions, the structure of the electrodes, the level of hydration (solvent saturation), etc [3,4,5,6,7].…”

“…The objective of this paper is to extend the work on large deflection bending curve model to derive the shape vs. applied voltage by the same authors in [2] to introduce an input output model for IPMC control. The concept of deriving an equivalent electric network model with standard components is adopted here.…”