Electrically Conductive and Highly Stretchable Piezoresistive Polymer Nanocomposites via Oxidative Chemical Vapor Deposition

Abstract

Electrically conductive polymer nanocomposites have been the subject of intense research due to their promising potential as piezoresistive biomedical sensors, leveraging their flexibility and biocompatibility. Although intrinsically conductive polymers such as polypyrrole (PPy) and polyaniline have emerged as lucrative candidates, they are extremely limited in their processability by conventional solution-based approaches. In this work, ultrathin nanostructured coatings of doped PPy are realized on polyurethane films of different architectures via oxidative chemical vapor deposition to develop stretchable and flexible resistance-based strain sensors. Holding the substrates perpendicular to the reactant flows facilitates diffusive transport and ensures excellent conformality of the interfacial integrated PPy coatings throughout the 3D porous electrospun fiber mats in a single step. This allows the mechanically robust (stretchability > 400%, with fatigue resistance up to 1000 cycles) nanocomposites to elicit a reversible change of electrical resistance when subjected to consecutive cycles of stretching and releasing. The repeatable performance of the strain sensor is linear due to dimensional changes of the conductive network in the low-strain regime (ε ≤ 50%), while the evolution of nano-cracks leads to an exponential increase, which is observed in the high-strain regime, recording a gauge factor as high as 46 at 202% elongational strain. The stretchable conductive polymer nanocomposites also show biocompatibility toward human dermal fibroblasts, thus providing a promising path for use as piezoresistive strain sensors and finding applications in biomedical applications such as wearable, skin-mountable flexible electronics.

Flexible Piezoresistive Sensors Based on PPy Granule-Anchored Multilayer Fibrous Membranes with a Wide Operating Range and High Sensitivity

“…The peak at 795 cm –1 is due to the characteristic absorption peak of α–α-linked pyrroles. , When comparing PPF and PPFP, it can be observed that PPFP initially undergoes less mass degradation at 100 °C. This is because the chloride dopants and volatile small molecules derived from the short-chain PPy oligomers evaporate during the heating process . As the temperature rises, the carbonyl groups in PPF begin to break down, leading to a rapid deterioration in the quality of the PPF fibrous membrane.…”

Recent Progress and Challenges of Implantable Biodegradable Biosensors

“…Silicon nanowires (SiNWs) and conductive polymers are frequently employed as piezoresistive materials. These sensors are known for their precision in static force measurements and compatibility with microfabrication techniques, making them ideal for integrating into wearable and implantable devices [202,203]. Both sensing mechanisms have been effectively applied in the design of bioelectronic devices to measure forces that are relatively small, yet critical for understanding physiological conditions.…”

Research on the Solid–Liquid Composite Casting Process of Incoloy825/P110 Steel Composite Pipe

“…Composite materials are formed by combining two or more materials with different chemical or physical properties to create a new material with distinct physical or chemical characteristics. With the advancement of modern technology, composite materials have been widely applied in various important and innovative industries both domestically and internationally, such as bio-composite materials [1], aerospace, maritime transportation, mechanical structural materials [2], and civil engineering [3][4][5]. Recent studies have shown that composite materials are widely used in automotive, underwater, and structural applications.…”