Polypyrrole-Doped Conductive Supramolecular Elastomer with Stretchability, Rapid Self-Healing, and Adhesive Property for Flexible Electronic Sensors

Abstract

Although recent years have witnessed intense efforts and innovations in the design of flexible conductive materials for the development of next-generation electronic devices, it remains a great challenge to integrate multifunctionalities such as stretchability, self-healing, adhesiveness, and sensing capability into one conductive system for practical applications. In this work, for the first time, we have prepared a new electrically conductive elastomer composite that combines all these functionalities by triggering in situ polymerization of pyrrole in a supramolecular polymer matrix cross-linked by multiple hydrogen-bonding 2-ureido-4­[1H]-pyrimidinone (UPy) groups. The polypyrrole (PPy) particles were uniformly dispersed and imparted to the composite desirable conductive properties, while the reversible nature of the dynamic multiple hydrogen bonds in the polymer matrix allowed excellent stretchability, fast self-healing ability, and adhesiveness under ambient condition. The elastomer composite with the incorporation of 7.5 wt % PPy displayed a mechanical strength of 0.72 MPa with an elongation over 300%, where the rapid self-healing of the mechanical and electrical properties was achieved within 5 min. The elastic material also exhibited strong adhesiveness to a broad range of inorganic and organic substrates, and it was further fabricated as a strain sensor for the detection of both large and subtle human motions (i.e., finger bending, pulse beating). The novel PPy-doped conductive elastomer has demonstrated great potential as functional sensors for wearable electronics, which provides a facile and promising approach to the development of various flexible electronic materials with multifunctionalities by combining conductive components with supramolecular polymers.

Mechanically Strong and Highly Stiff Supramolecular Polymer Composites Repairable at Ambient Conditions

“…Even so, intrinsic healing materials, capable of healing under ambient conditions are generally soft and deformable and mostly in the form of hydrogels or elastomers that feature high polymer chain mobility/flexibility. 6,23,25,[33][34][35][36][37][38][39][40][41][42] Unfortunately, it is a formidable challenge to fabricate high-strength and stiff polymeric materials that could heal damages intrinsically under ambient conditions. This is because the diffusion of the polymer chains in rigid materials is hindered significantly, and the rigidity is not favorable for the intimate contact between fractured interfaces.…”

Wearable Devices Using Nanoparticle Chains as Universal Building Blocks with Simple Filtration‐Based Fabrication and Quantum Sensing

“…The presence of a series of tunneling junctions makes the device sensitive to small modulations in the surface potential. [ 15,21 ] This is further confirmed by having a reference electrode with the device (a three electrode set‐up) in aqueous medium and using it to act as a liquid gate. [ 21 ] The change in the gate voltage modulates the current in the device and even changes of 0.5 mV in gate potential can be detected (Figure S8, Supporting Information) with a sensitivity of 1.2 µA V −1 .…”

“…[ 10–13 ] At the same time the wearable device should be made from materials that can be safely handled by users without any health hazards. A variety of materials and strategies have been used to make devices that can accomplish such tasks, typically using a combination of materials such as CNT, [ 14 ] elastomers, [ 15 ] trace patterns of thin films of metals, [ 5 ] metallic [ 16,17 ] and semi conducting nanomaterials, [ 18 ] piezoelectric materials, [ 19 ] thermoelectric materials, [ 11 ] and so on. The fabrication of the devices typically involves multiple steps with deposition of a variety of materials which act as the sensing layers for different stimuli, interconnects and the electrodes.…”

Advances in Materials for Soft Stretchable Conductors and Their Behavior under Mechanical Deformation

“…Varying the PEIE concentration allows researchers to tune the mechanical characteristics as the PEIE additive will soften mechanical modulus and increase stretchability and adhesion force of the adapted PDMS elastomer [ 208 ]. Other chemical modifications involve polymerizing supramolecular elastomers with conductive polymers that display both self-healing and self-adhesive properties [ 209 ].…”