Sequential growth and monitoring of a polypyrrole actuator system

Abstract

Electroactive polymers (EAPs) have emerged as viable materials in sensing and actuating applications, but the capability to mimic the structure and function of natural muscle is increased due to their ability to permit additional, sequential synthesis steps between stages of actuation. Current work is improving upon the mechanical performance in terms of achievable stresses, strains, and strain rates, but issues still remain with actuator lifetime and adaptability. This work seeks to create a bioinspired polymer actuation system that can be monitored using state estimation and adjusted in vivo during operation. The novel, time-saving process of sequential growth was applied to polymer actuator systems for the initial growth, as well as additional growth steps after actuation cycles. Synthesis of conducting polymers on a helical metal electrode directs polymer shape change during actuation, assists in charge distribution along the polymer for actuation, and as is described in this work, constructs a constant working electrode/polymer connection during operation which allows sequential polymer growth based on a performance need. The polymer system is monitored by means of a reduced-order, state estimation model that works between growth and actuation cycles. In this case, actuator stress is improved between growth cycles. The ability for additional synthesis of the polymer actuator not only creates an actuator system that can be optimized based on demand, but creates a dynamic actuator system that more closely mimics natural muscle capability.

Synthesis and Characterization of the Conducting Polymer Micro-Helix Based on the Spirulina Template

“…The conducting polymers in helical micro/nanostructures have also been reported using both template- and non-template-based methods [21,44,45]. Among these methods, the templates are critical for the fabrication of highly-ordered helical microstructures of the conducting polymers [45,46,47,48]. Thus, it will be interesting and worthy to utilize Spirulina as a helical bio-templates which can be easily reproduced en masse and with low cost.…”