Stretchable and Healable Conductive Elastomer Based on PEDOT:PSS/Natural Rubber for Self-Powered Temperature and Strain Sensing

Abstract

Self-powered elastic Conductors based on thermoelectric materials with the ability to harvest energy from the living environment are considered as important for electronic devices under off-grid, maintenance-free, or unfeasible battery replacement circumstances. Poly(3,4-ethylenedioxythiophene)-poly-(styrenesulfonate) (PEDOT:PSS) is perhaps the most well-known organic conductor. However, the application of PEDOT:PSS in flexible devices is limited by its brittleness and various unrecoverable properties under strain. Various polymer blends based on water-soluble polymers and PEDOT:PSS have been prepared. Nevertheless, they fail to illustrate good balance between electrical conductivity and mechanical performance due to various issues, including the phase morphology with PEDOT:PSS as the dispersed phase; thus, the formation of a conductive network between PEDOT:PSS is prohibited. In this study, PEDOT:PSS is incorporated into natural rubber (NR), with NR as the dispersed phase. For 10 wt % PEDOT:PSS−NR composite films doped with dimethyl sulfoxide (DMSO), the conductivity was up to 87 S/cm and the elongation at break was maintained at 490%. More importantly, self-powered temperature-and tensile strain-sensing abilities were also realized. Furthermore, it is also demonstrated that most of the unrecoverable strain and conductivity under cyclic tensile strain could be healed by water and phosphate-buffered saline (PBS) post-treatment. This work provides interesting insights for preparing healed and stretchable self-powered electronic sensors.

Stretchable Thermoelectrics: Strategies, Performances, and Applications

“…On account of considering to enhance both stretchability and thermoelectric performance, Yang et al proposed a composite film incorporating PEDOT:PSS treated by EG and DMSO with natural rubber (NR), then treated by water and phosphatebuffered saline to realize strain and conductivity recovery (Figure 3a). [43] The composite film with 10 wt% PEDOT:PSS possessed electrical conductivity of 4.1 S cm −1 and 31 µV K −1 Seebeck coefficient (Figure 3b). The composite film exhibited brilliant strain sensing performance at even 100% tensile strain (Figure 3c) and presented wrinkles under the free state due to the interlacing of rubber particles.…”

“…d) Surface SEM images of 10 wt% composite films under various tensile strains. e) Morphology deformation of the composite films under tensile strain.Reproduced with permission [43]. Copyright 2021, American Chemical Society.…”

Recent progress in flexible tactile sensor systems: from design to application

“…For example, Qiu et al [88] reported a dual-mode sensor based on interlocked piezoresistive and piezoelectric films, realizing the complementary performance of the two sensing mechanisms, and thus improving the sensitivity and broadening the sensing range [Figure 5A]. Hwang et al [89] reported a transparent sensor combining piezoresistive and capacitive transduction mechanisms, which can distinguish touch and pressure, as shown in Figure 5B. Besides the direct combination of two sensing mechanisms in a single device design, a single sensor can respond to a variety of stimuli by selecting specific functional materials.…”

“…(B) Schematic diagram and current versus time of the transparent dual-mode sensor, which can distinguish touch and pressure. Reproduced with permission from Ref [89]. .…”

Enhanced thermoelectric performance of graphene based nanocomposite coated self-powered wearable e-textiles for energy harvesting from human body heat

“… 34 Such polymer based composites are generally fabricated using in situ , chemical oxidation, vapor phase polymerization, and chemical exfoliation, 35–37 whereas the filler are widely mixed with different organic solvents, reducing agents, dispersing agents and stabilizers. 38 The features of the intrinsic conductive polymers are not only limited to their potential electrical and thermal properties but due to their light weight, flexibility and higher stability against water, and air makes them highly suitable for super capacitors, batteries, solar cells, and other energy storage and harvesting devices. 39 Furthermore, chemical functionalization and in situ solution processed polymer composite are commonly used including screen printing, ink jet printing dispenser printing; spray printing, and spin coating, 40,41 as an efficient, cost-effective method to fabricate TE devices on mass scale.…”