Fabrication and sensing development of electroactive polymers

Abstract

Ionic polymer-metal composites (IPMCs) are one of the most interesting types of “smart materials". The “smart” denomination for these materials comes from the active deformation response of them to an electric field. Ionic polymers in any of their different forms are the basic concept in the field of smart actuating and energy harvesting function.

IPMCs have attracted lots of interest for a wide range of applications, from aerospace to medicine. These materials have been extensively used as actuators for many years but in order to improve their efficiency and applicability, a simultaneous sensing response should also be implemented in their function. The recent development of IPMCs as sensors-actuators has started up a whole new research field on self-sensing techniques and devices.

In this work, we present a new and improved self-sensing method for IPMC, which exhibits a series of advantages in comparison to other commonly employed methods. Two of the most usual self-sensing methods that have been used until now are mechanical-to-electrical transduction and surface resistance detection. Both of them have several drawbacks related to the cross-talk noise and the needs of especial modifications on the sample. With our technique, the IPMCs can work simultaneously as an actuator and a sensor without any interruption or interference between both operations. Additionally, our self-sensing technique does not require any extra sample modification of the IPMC to measure external disturbance on normal bending.

In addition, we have carried out a systematic study to reveal the mechanisms behind this novel self-sensing method. We have also performed simulation in order to optimize the system and find out which parameters improve the effective sensor signal. Concerning the miniaturizing part, we have also investigated the minimum size required for the self-sensing operation of this improved technique.