Transmission line circuit model of a PPy based trilayer mechanical sensor

Abstract

Many efforts have been devoted to modeling the diffusive impedance of conjugated polymer (CP) based actuators using their equivalent electrical circuits. Employing the same methodology, CP based mechanical sensors can also be treated by an equivalent transmission line circuit and their overall impedance can be modeled, correspondingly. Due to the large number of resources to study the electrical circuits, this technique is a practical tool. Therefore, in this study, an equivalent RC-circuit model including electrochemical parameters is determined to obtain a better perception of the sensing mechanism of these mechanical sensors. Conjugated polymers are capable of generating an output current or voltage upon an induced mechanical deformation or force. This observed behavior in polymer based mechanical sensors is considered as the reverse actuation process. Many outstanding properties of the conjugated polymer actuators including their light weight and biocompatibility are still retained by these sensors. Sensors with a trilayer configuration are capable of operating in air in response to a mechanically induced bending deformation. However, due to their nonlinear behavior and multivariable characteristics, it is required to propose a systematic approach in order to optimize their performance and gain the optimal values of their constituent decision variable. Therefore, the proposed mathematical model is used to define the output voltage of the PPy based mechanical sensor along with the sensitivity of the model to the applied frequency of the induced deformation. Applying a multiobjective optimization algorithm, the optimization problem was solved and the tracking ability of the proposed model was then verified.

Characterization and dynamic charge dependent modeling of conducting polymer trilayer bending

“…They proposed a symmetric configuration for trilayers with a resistor between CP layers to model the separator resistance [17]. To relate the current passing through the CP layers to the applied voltage, total impedance of the trilayer was obtained using the 2D transmission line model [19]. A diffusion element in series with a double layer capacitance represents each CP layer and a single resistor connects the two transmission lines.…”

Recent Advances on Polypyrrole Electroactuators

“…Designs of PPy electroactuators encompass a monolithic, bilayered, or trilayered structure [ 22 , 97 , 98 ]. Monolithic and bilayered implementations are primarily used in applications involving a supporting liquid electrolyte (either aqueous or organic), while trilayered ones are employed with an ionic gel electrolyte sandwiched between two PPy films for operation in air [ 23 , 99 , 100 , 101 ]. Due to longitudinal voltage attenuation along a semiconducting CP strip, a monolithic electroactuator’s tail usually generates smaller strain than its upper section [ 72 ], resulting in a notable strain gradient along the strip ( Figure 2 b).…”