A recyclable PANI/PAAMPSA nanocomposite with repeatable, rapid, autonomous self-healing, and unprecedented electro-mechanical properties

Abstract

Wearable sensors, stretchable electronics, and many soft robotic materials must have a balance of conductivity, stretchability, and robustness. Intrinsically conductive polymers offer a critical step toward improving wearable sensor materials due to their tunable conductivity, soft/compliant nature, and ability to complex with other coactive molecules (i.e., polyacids, small molecules). The addition of synergistic nanofillers has been shown to enhance the conductivity, self-healing, and mechanical properties of the polymers for soft robotics and wearable applications. The development of a robust polymer nanocomposite material that offers ultra-stretchability, an autonomous self-healing ability, and enhanced electronic properties has long eluded researchers. Herein, we show an aqueous polyaniline [PANI]:poly(2-acrylamido-2-methylpropane sulfonic acid) [PAAMPSA]:phytic acid [PA] polymer complex synthesized with 0.5 wt % silver nanowires (AgNW) to form a polymer nanocomposite with high electronic sensitivity, unique mechanical properties (a maximum strain of 4693%) and repeatable/autonomous self-healing efficiencies of greater than 98%. This AgNW polymer complex has an engineering strain higher than any reported hydrogel or other polymer-based sensor materials, in which the interface between the polymer matrix and the AgNW is hypothesized to be integral for the formation of the active electrically conductive network and unprecedented mechanical properties. To illustrate the remarkable sensitivity, the material was employed as a biomedical sensor (pulse, voice recognition, motion), topographical sensor, and high-sensitivity strain gauge.