PSS Composite Films Research Articles

Highly Stable Flexible Organic Electrochemical Transistors with Natural Rubber Latex Additives.

Organic electrochemical transistors (OECTs) have attracted considerable interest in the context of wearable and implantable biosensors due to their remarkable signal amplification combined with seamless integration into biological systems. These properties underlie OECTs' potential utility across a range of bioelectronic applications. One of the main challenges to their practical applications is the mechanical limitation of PEDOT:PSS, the most typical conductive polymer used as a channel layer, when the OECTs are applied to implantable and stretchable bioelectronics. In this work, we address this critical issue by employing natural rubber latex (NRL) as an additive in PEDOT:PSS to improve flexibility and stretchability of the OECT channels. Although the inclusion of NRL leads to a decrease in transconductance, mainly due to a reduced carrier mobility from 0.3 to 0.1 cm2/V·s, the OECTs maintain satisfactory transconductance, exceeding 5 mS. Furthermore, it is demonstrated that the OECTs exhibit excellent mechanical stability while maintaining their performance even after 100 repetitive bending cycles. This work, therefore, suggests that the NRL/PEDOT:PSS composite film can be deployed for wearable/implantable applications, where high mechanical stability is needed. This finding opens up new avenues for practical use of OECTs in more robust and versatile wearable and implantable biosensors.

Spin coated ultrathin PEDOT:PSS/SWCNT film with high electronic conductivity

Conductive Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been extensively used as non-metallic electrodes. However, the relatively low electrical conductivity of pristine PEDOT:PSS film restricts its further application. Although doping high content conductive filler or increasing the film thickness are effective for enhancing the electrical property, the transparency is sacrificed, which limits the application of PEDOT:PSS films. In this study, preparing PEDOT:PSS composite film with highly conductive and transparent property was the primary purpose. To achieve this goal, single-walled carbon nanotubes (SWCNTs) and dimethyl sulfoxide (DMSO) was chosen to composite with PEDOT:PSS. The spin-coated SWCNT/PEDOT:PSS composite film exhibited excellent electrical conductivity and transparency. The electrical conductivity of composite film with desired transmittance property (78%) reached the highest value (1060.96 S cm−1) at the SWCNTs content was 6 wt%. Under the modification process applied in this work, the non-conductive PSS was partially removed by incorporated DMSO and SWCNTs. Then, the molecular chains of PEDOT stretched and adsorbed onto the surface of SWCNTs, forming a highly efficient three-dimensional conductive structure, which contributed to the enhancement of electrical conductivity and transparency. Additionally, the spin-coating process allowed for the reduction of film thickness, ensuring better transparency. This research contributed to expanding the further applications of PEDOT:PSS films in high-performance transparent film electrodes.

Enhanced thermal conductivity in vertically grown ZnO Nanorods/ Poly(3,4-ethylenedioxithiophene): Poly(4-styrenesulfonate) composite thin films

Herein, we have investigated the thermal properties of compact and vertically grown ZnO nanorods (NRs)/poly(3,4-ethylenedioxithiophene):poly(4-styrenesulfonate) (PEDOT:PSS) composite film. The ZnO NR arrays with length 885 ± 5 nm have been grown using the sol–gel method. Furthermore, composite films of compact-ZnO and ZnO NR with PEDOT:PSS have also been grown. The temperature-dependent thermal conductivity for both the composite films has been investigated in the temperature range of 273–353 K. The thermal conductivity of compact-ZnO/PEDOT:PSS is found to be in between 1.43–1.49 W/mK. The thermal conductivity is found to be enhanced significantly in the case of ZnO NR/PEDOT:PSS composite film.

Electrochromic Devices Based on 2D MoO3-x/PEDOT:PSS Composite Film with Boosted Ion Transport.

Electrochromic materials allow for optical modulation and have attracted much attention due to their bright future in applications such as smart windows and energy-saving displays. Two-dimensional (2D) molybdenum oxide nanoflakes with combined advantages of high active specific surface area and natural layered structure should be highly potential candidates for electrochromic devices. However, the efficient top-down preparation of 2D MoO3 nanoflakes is still a huge challenge and the sluggish ionic kinetics hinder its electrochromic performance. Herein, we demonstrated a feasible thiourea-assisted exfoliation procedure, which can not only increase the yield but also reduce the thickness of 2D MoO3-x nanoflakes down to a few nanometers. Furthermore, electrophoretic-deposited MoO3-x nanoflakes were combined with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)-conjugated polymer to simultaneously enhance the ionic kinetics and electronic conductivity, with a diffusion coefficient of 3.09 × 10-10 cm2 s-1 and a charge transport resistance of 33.7 Ω. The prepared 2D MoO3-x/PEDOT:PSS composite films exhibit improved electrochromic performance, including fast switching speed (7 s for bleaching, 5 s for coloring), enhanced coloration efficiency (87.1 cm2 C-1), and large transmittance modulation (ΔT = 65%). This study shows outstanding potential for 2D MoO3-x nanoflakes in electrochromic applications and opens new avenues for optimizing the ion transport in inorganic-organic composites, which will be possibly inspired for other electrochemical devices.

Additive Blending Effects on PEDOT:PSS Composite Films for Wearable Organic Electrochemical Transistors.

Organic electrochemical transistors (OECTs) employing conductive polymers (CPs) have gained remarkable prominence and have undergone extensive advancements in wearable and implantable bioelectronic applications in recent years. Among the diverse arrays of CPs, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is a common choice for the active-layer channel in p-type OECTs, showing a remarkably high transconductance for the high amplification of signals in biosensing applications. This investigation focuses on the novel engineering of PEDOT:PSS composite materials by seamlessly integrating several additives, namely, dimethyl sulfoxide (DMSO), (3-glycidyloxypropyl)trimethoxysilane (GOPS), and a nonionic fluorosurfactant (NIFS), to fine-tune their electrical conductivity, self-healing capability, and stretchability. To elucidate the intricate influences of the DMSO, GOPS, and NIFS additives on the formation of PEDOT:PSS composite films, theoretical calculations were performed, encompassing the solubility parameters and surface energies of the constituent components of the NIFS, PEDOT, PSS, and PSS-GOPS polymers. Furthermore, we conducted a comprehensive array of material analyses, which reveal the intricacies of the phase separation phenomenon and its interaction with the materials' characteristics. Our research identified the optimal composition for the PEDOT:PSS composite films, characterized by outstanding self-healing and stretchable capabilities. This composition has proven to be highly effective for constructing an active-layer channel in the form of OECT-based biosensors fabricated onto polydimethylsiloxane substrates for detecting dopamine. Overall, these findings represent significant progress in the application of PEDOT:PSS composite films in wearable bioelectronics and pave the way for the development of state-of-the-art biosensing technologies.

MXene-based wearable thermoelectric respiration sensor

Respiration rate (RR) holds a pivotal status as a vital sign, with its deviation serving as a significant marker for grave clinical occurrences. Contemporary methods for RR detection involve the utilization of complex and costly apparatus, potentially disrupting the innate breathing process. An imperative arises for the development of wearable respiratory sensors that exhibit attributes of cost-effectiveness and efficiency. This study introduces a pioneering investigation featuring an MXene/CNT/PEDOT:PSS composite film, which leverages the thermoelectric effect for sensing RR. After integrating with heart rate monitoring, real-time human health surveillance becomes achievable. Additionally, a notable enhancement in tensile strength by a factor of 2.4 is observed, along with an improved electromagnetic shielding efficiency of 59 dB, representing a 1.5-fold increase, as well as a commendable self-heating capability. The construction of the brick-mortar-structured MXene-based film shows promising potential for respiration sensing, offering additional healthcare functions such as electromagnetic shielding and self-heating. This innovation expands the application scope of MXene within the sensor field, contributing to the advancement of healthcare technologies.

Fabrication of Highly Conductive Porous Fe3O4@RGO/PEDOT:PSS Composite Films via Acid Post-Treatment and Their Applications as Electrochemical Supercapacitor and Thermoelectric Material.

As a remarkable multifunctional material, ferroferric oxide (Fe3O4) exhibits considerable potential for applications in many fields, such as energy storage and conversion technologies. However, the poor electronic and ionic conductivities of classical Fe3O4 restricts its application. To address this challenge, Fe3O4 nanoparticles are combined with graphene oxide (GO) via a typical hydrothermal method, followed by a conductive wrapping using poly(3,4-ethylenedioxythiophene):poly(styrene sulfonic sulfonate) (PEDOT:PSS) for the fabrication of composite films. Upon acid treatment, a highly conductive porous Fe3O4@RGO/PEDOT:PSS hybrid is successfully constructed, and each component exerts its action that effectively facilitates the electron transfer and subsequent performance improvement. Specifically, the Fe3O4@RGO/PEDOT:PSS porous film achieves a high specific capacitance of 244.7 F g-1 at a current of 1 A g-1. Furthermore, due to the facial fabrication of the highly conductive networks, the free-standing film exhibits potential advantages in flexible thermoelectric (TE) materials. Notably, such a hybrid film shows a high electric conductivity (σ) of 507.56 S cm-1, a three times greater value than the Fe3O4@RGO component, and achieves an optimized Seebeck coefficient (S) of 13.29 μV K-1 at room temperature. This work provides a novel route for the synthesis of Fe3O4@RGO/PEDOT:PSS multifunctional films that possess promising applications in energy storage and conversion.

Flexible free-standing BixSey@C/PEDOT:PSS thermoelectric composite film with high-performance electromagnetic interference shielding

Due to the component advantages and structural features, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) based inorganic–organic composite films shows huge application potential in various fields. However, there are few reports on the bi-functions of thermoelectric (TE) and electromagnetic interference (EMI) shielding for the PEDOT:PSS-based functional films. Herein, metal–organic frameworks (MOFs)-derived BixSey@C sheets with average size about ∼ 7.32 μm are obtained via the solvothermal reaction and selenization pyrolysis treatment, and then flexible free-standing BixSey@C/PEDOT: PSS (BSCP) composite films are obtained by a feasible vacuum filtration combined with cold pressing treatment, using different contents of BixSey@C content as inorganic component. Micrometer BixSey@C sheets are uniformly dispersed in the PEDOT:PSS matrix constructing bi-functional composite films with unique layered structure. When the MOFs-derived BixSey@C content is 70%, BSCP-70 composite film gets a power factor of 11.23 μW m−1 K−2 at 340 K. Meanwhile, the BSCP-70 composite film reaches the highest average total EMI shielding effectiveness (SET) value of 45.0 dB at only 41.9 μm thickness at X-band. Based on multi-physical properties of MOF-derived BixSey@C and PEDOT:PSS, flexible BixSey@C/PEDOT:PSS composite films display good application potentiality in the flexible TE devices and EMI shielding protection.

Ultrasensitive mechanical/thermal response of a P(VDF-TrFE) sensor with a tailored network interconnection interface

Ferroelectric polymers have great potential applications in mechanical/thermal sensing, but their sensitivity and detection limit are still not outstanding. We propose interface engineering to improve the charge collection in a ferroelectric poly(vinylidene fluoride-co-trifluoroethylene) copolymer (P(VDF-TrFE)) thin film via cross-linking with poly(3,4-ethylenedioxythiophene) doped with polystyrenesulfonate (PEDOT:PSS) layer. The as-fabricated P(VDF-TrFE)/PEDOT:PSS composite film exhibits an ultrasensitive and linear mechanical/thermal response, showing sensitivities of 2.2 V kPa−1 in the pressure range of 0.025–100 kPa and 6.4 V K−1 in the temperature change range of 0.05–10 K. A corresponding piezoelectric coefficient of −86 pC N−1 and a pyroelectric coefficient of 95 μC m−2 K−1 are achieved because more charge is collected by the network interconnection interface between PEDOT:PSS and P(VDF-TrFE), related to the increase in the dielectric properties. Our work shines a light on a device-level technique route for boosting the sensitivity of ferroelectric polymer sensors through electrode interface engineering.

SnS/PEDOT:PSS composite films with enhanced surface conductivities induced by solution post-treatment and their application in flexible thermoelectric

SnS/PEDOT:PSS composite films with enhanced surface conductivities induced by solution post-treatment and their application in flexible thermoelectric

Highly Electrical Conductive PEDOT:PSS/SWCNT Flexible Thermoelectric Films Fabricated by a High-Velocity Non-solvent Turbulent Secondary Doping Approach.

Materials based on poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) can be potentially employed as flexible thermoelectric generators (TEGs) to capture waste heat and generate electrical energy. Among various methods, secondary doping is an effective way to modulate its thermoelectric (TE) performance. Different from conventional measures such as dropping, soaking, and steam fumigation, strong shear is integrated with the doping process and termed high-velocity non-solvent turbulent secondary doping (HNTD). We systematically investigate the transformation of PEDOT:PSS during this procedure and the formation mechanism of its highly conductive pathway. It is illustrated that PEDOT:PSS experiences PSS swelling, the phase separation of PEDOT from PSS, the removal of isolated PSS, and the evolution of PEDOT to a linear conformation. These evolutions contribute to the substantial elevation of electrical conductivity (σ). Furthermore, by employing continuous single-walled carbon nanotube (SWCNT) networks as structural units, highly conductive flexible PEDOT:PSS/SWCNT TE thin films could be prepared without sacrificing the Seebeck coefficient (S). Additionally, the effect of HNTD and direct addition method on TE properties of composite films is also compared. Finally, the PEDOT:PSS composite film with 40 wt % SWCNTs by the HNTD method exhibits the maximized power factor (PF) of 501.31 ± 19.23 μW m-1 K-2 with σ of 4717.8 ± 41.51 S cm-1 and S of 32.6 ± 0.13 μV K-1 at room temperature. It is worth mentioning that the σ value 4717.8 ± 41.51 S cm-1 is the highest among the composites based on commercial carbon fillers and organic semiconductors. Finally, a 6-leg TEGs prototype is assembled and illustrates an output power of 4.416 μW under a temperature difference (ΔT) of 58 K. It is thought that such a strategy may provide some guidelines for manufacturing PEDOT:PSS-based functional materials.

Flexible Te/PEDOT:PSS thin films with high thermoelectric power factor and their application as flexible temperature sensors.

Flexible, lightweight, and low-cost thermoelectric thin films are promising for self-powered wearable electronics and sensors. In this work, we report on flexible Te nanostructures/PEDOT:PSS composite thin films with high power factor and their application as flexible temperature sensors. Te nanostructures with high crystallinity and high aspect ratios were synthesized through an environmentally friendly method without using highly toxic chemicals. Individual Te nanostructures achieve a thermoelectric figure of merit (ZT) of 0.13 at 300 K, indicating good potential as inorganic fillers for nanostructures/polymer hybrid materials. Based on the synthesized Te nanostructures, flexible p-type Te/PEDOT:PSS thin films were fabricated through a simple dilution and vacuum filtration method. The power factor of the as-prepared composite thin film outperforms that of either a Te or DMSO-treated PEDOT:PSS thin film, and importantly, it can be further enhanced to 149 μW m-1 K-2 by hot pressing, which is nearly threefold enhancement compared to the values reported for the vacuum-filtered flexible Te/PEDOT:PSS thin films in the literature. The hot-pressed composite thin film shows high flexibility with the electrical conductivity remaining almost unchanged after 1000 bending cycles under a bending radius of 5 mm. Flexible temperature sensors were fabricated based on the hot-pressed Te/PEDOT:PSS thin film, which exhibited high sensitivity in detecting temperature stimuli. The developed temperature sensors were applied onto a two-finger flexible mechanical claw for identifying hot/cold objects in robotic grasping. This work demonstrates an effective approach to enhance the thermoelectric power factor of flexible Te nanostructures/polymer composites and their promising application in flexible thermal sensing.

Ginkgo Leaf Inspired Fabrication of Micro/Nanostructures and Demonstration of Flexible Enzyme-Free Glucose Sensors.

Flexible enzyme-free glucose sensors have attracted widespread attention due to their importance and potential applications in clinical diagnosis, flexible wearable devices, and implanted devices in vivo. At present, there are still major problems in fabricating flexible enzyme-free glucose sensors with low detection limits, high stability, and high sensitivity at low cost, hindering their practical application. Here, we report a facile strategy for the fabrication of flexible non-enzymatic glucose sensors using ginkgo leaf as a template. NiO film and PEDOT:PSS composite film were deposited on the surface of the ginkgo leaf induced micro-nano hierarchical structure as a sensitive layer and a conductive layer, respectively. The as-prepared, flexible, enzyme-free glucose sensor exhibited excellent electrochemical performance toward glucose oxidation with a sensitivity of 0.7413 mA·mM−1/cm−2, an operating voltage of 0.55 V, a detection limit of 0.329 μM, and good anti-interference. Due to the simple fabrication process and performance reliability, the novel flexible enzyme-free glucose sensor is an attractive candidate for next generation wearable and implantable non-enzymatic glucose diagnostic devices.

Highly Conductive, Flexible, and Robust Silver Nanowire-Embedded Carboxymethyl Cellulose/Poly(3,4-Ethylenedioxythiophene):Poly(Styrenesulfonate) Composite Films for Wearable Heaters and On-Skin Sensors

Highly conductive, flexible, and durable silver nanowire (AgNW)-embedded carboxymethyl cellulose (CMC)/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) (s-CMC/PEDOT:PSS) composite films were investigated for application in wearable heaters and on-skin sensors. The electrical conductivities of the CMC/PEDOT:PSS composites were optimized by controlling the PEDOT:PSS weight ratio in CMC, and the sheet resistance decreased significantly from 6828 (CMC:PEDOT:PSS = 1:5) to 83 Ω/sq (CMC:PEDOT:PSS = 1:17). Furthermore, AgNW networks were embedded onto the surface of the CMC/PEDOT:PSS films to further enhance their conductivity. The introduction of AgNW networks resulted in a significant decrease in the sheet resistance of the composites from 81 to 7 Ω/sq. In addition, the s-CMC/PEDOT:PSS composite film exhibited high mechanical stability in repeated bending tests. The uniformly distributed AgNWs inside the composites enhanced the electrical contact between the conducting PEDOT:PSS domains in the CMC matrix. Based on the highly conductive, flexible, and robust s-CMC/PEDOT:PSS composite films, high-performance wearable heating devices and on-skin sensors were fabricated. The wearable heater achieves a high temperature of 159.5 ℃ with uniform temperature distribution. Furthermore, on-skin sensors with s-CMC/PEDOT:PSS composites were conformably integrated on human skin which successfully detected various human motions, including finger bending, wrist bending, skin touch, ankle motions, and walking in real-time. The sensors exhibit high sensing performance with high sensitivity, conformability, superior mechanical robustness, and low power consumption. The high-performance s-CMC/PEDOT:PSS composite film could be a promising flexible and conductive composite material with new opportunities in next-generation electronics.Graphical Abstract

Stretchable and Conductive Cellulose/Conductive Polymer Composite Films for On-Skin Strain Sensors.

Conductive composite materials have attracted considerable interest of researchers for application in stretchable sensors for wearable health monitoring. In this study, highly stretchable and conductive composite films based on carboxymethyl cellulose (CMC)-poly (3,4-ethylenedioxythiopehe):poly (styrenesulfonate) (PEDOT:PSS) (CMC-PEDOT:PSS) were fabricated. The composite films achieved excellent electrical and mechanical properties by optimizing the lab-synthesized PEDOT:PSS, dimethyl sulfoxide, and glycerol content in the CMC matrix. The optimized composite film exhibited a small increase of only 1.25-fold in relative resistance under 100% strain. The CMC-PEDOT:PSS composite film exhibited outstanding mechanical properties under cyclic tape attachment/detachment, bending, and stretching/releasing tests. The small changes in the relative resistance of the films under mechanical deformation indicated excellent electrical contacts between the conductive PEDOT:PSS in the CMC matrix, and strong bonding strength between CMC and PEDOT:PSS. We fabricated highly stretchable and conformable on-skin sensors based on conductive and stretchable CMC-PEDOT:PSS composite films, which can sensitively monitor subtle bio-signals and human motions such as respiratory humidity, drinking water, speaking, skin touching, skin wrinkling, and finger bending. Because of the outstanding electrical properties of the films, the on-skin sensors can operate with a low power consumption of only a few microwatts. Our approach paves the way for the realization of low-power-consumption stretchable electronics using highly stretchable CMC-PEDOT:PSS composite films.

Highly stretchable and robust transparent conductive polymer composites for multifunctional healthcare monitoring

ABSTRACT Soft, stretchable, conductive thin films have propelled to the forefront of applications in stretchable sensors for on-skin health monitoring. Stretchable conductive films require high conformability, stretchability, and mechanical/chemical stability when integrated into the skin. Here, we present a highly stretchable, conductive, and transparent natural rubber/silver nanowire (AgNW)/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) composite film. Overcoating the PEDOT:PSS layer results in outstanding mechanical robustness and chemical stability by suppressing the mechanical and chemical degradation of the nanowire networks. Moreover, the introduction of the organic surface modifier enhances the bonding strength between the natural rubber substrate and AgNW at the interface. The highly conformable composite films are integrated into multifunctional on-skin sensors for monitoring various human motions and biological signals with low-power consumption. We believe that the highly stretchable, robust, and conformable natural rubber/AgNW/PEDOT:PSS composite film can offer new opportunities for next-generation wearable sensors for body motion and physiological monitoring.

Graphene: Hexagonal Boron Nitride Composite Films with Low-Resistance for Flexible Electronics

The structure and electric properties of hexagonal boron nitride (h-BN):graphene composite with additives of the conductive polymer PEDOT:PSS and ethylene glycol were examined. The graphene and h-BN flakes synthesized in plasma with nanometer sizes were used for experiments. It was found that the addition of more than 10−3 mass% of PEDOT:PSS to the graphene suspension or h-BN:graphene composite in combination with ethylene glycol leads to a strong decrease (4–5 orders of magnitude, in our case) in the resistance of the films created from these suspensions. This is caused by an increase in the conductivity of PEDOT:PSS due to the interaction with ethylene glycol and synergetic effect on the composite properties of h-BN:graphene films. The addition of PEDOT:PSS to the h-BN:graphene composite leads to the correction of the bonds between nanoparticles and a weak change in the resistance under the tensile strain caused by the sample bending. A more pronounced flexibility of the composite films with tree components is demonstrated. The self-organization effects for graphene flakes and polar h-BN flakes lead to the formation of micrometer sized plates in drops and uniform-in-size nanoparticles in inks. The ratio of the components in the composite was found for the observed strong hysteresis and a negative differential resistance. Generally, PEDOT:PSS and ethylene glycol composite films are promising for their application as electrodes or active elements for logic and signal processing.

High-Sensitivity Multiresponses Cellulose-Based Actuators with Configurable Amplitude

Actuators have many applications in artificial muscles, soft robots, and optical switches. Herein, we designed and fabricated a multifunctional actuator using cellulose composites that can be driven by humidity, natural sunlight, and electrothermal processes. Highly conductive and flexible cellulose, MXene, and PEDOT:PSS composite (CMPC) films were prepared with a facile blending-vacuum filtration method. Benefiting from the high conductivity, the CMPC film exhibited excellent performance in electromagnetic shielding, electrothermal processes, and humidity detection. Moreover, due to the hygroscopic properties of cellulose, CMPC film shows a negative coefficient of thermal expansion, in contrast to typical polymer films. By depositing a hydrophobic polytetrafluoroethylene (PTFE) film onto the CMPC film, a two-layer actuator was developed. Owing to the opposite thermal expansion properties of CMPC and PTFE, the as-obtained actuators exhibit a high sensitivity, and are made into bionic flowers, worms, robots, and smart curtains, showing fast responses to humidity, natural sunlight, and electrothermal processes. In fact, natural sunlight of 80 mW cm–2 or a power supply of as low as 3 V can drive the actuator to a bending curvature of 2.85 cm–1, corresponding to a bending angle of 360°. The bionic robot is configurable with movements and speeds that can be controlled by a microcontroller and have a wide application in biological bionic and soft robots.

A robust and flexible silver nanowire/silica sol/poly(3,4-ethylene dioxythiophene)/poly(styrene sulfonate) transparent conductive film for film heater

A robust, flexible and transparent silver nanowires(AgNWs)/silica sol/poly(3,4-ethylene dioxythiophene)/poly(styrene sulfonate) (PEDOT:PSS) composite film was fabricated for film heater via spray-coating AgNWs ink, silica sol and PEDOT:PSS onto the surface of polyethylene glycol terephthalate substrate in turn. Silica sol nanoparticles are absorbed around the AgNWs to improve the connection between AgNWs by capillary effect, and the PEDOT:PSS covers on the surface of AgNWs/silica sol layer to increase the network conductive paths and protect the AgNWs/silica sol layer. The AgNWs/silica sol/PEDOT:PSS composite film shows a sheet resistance of 12 Ω/sq, a transmittance of 87.5% at 550 nm and a Joule heating temperature of 99 °C at 15 V. The composite film with high mechanical stability, low surface roughness and corrosion resistance is promisingly used in window defrost and deicer system.

Foldable and highly flexible transparent conductive electrode based on PDMS/ Ag NWs/PEDOT: PSS

In this work, we can transfer poly (3,4-ethylenedioxythiophene): poly (styrenesulfonate) (PEDOT: PSS) from the glass substrate to the polydimethylsiloxane (PDMS) substrate by using HNO3 treatment, without losing the resistance and transmittance of the transparent conductive film, which overcome the hydrophobic characteristic of the PDMS substrate. The silver nanowires (Ag NWs) based flexible transparent electrode with PDMS as substrate is prepared. The PDMS/Ag NWs/PEDOT: PSS composite film shows a high transmittance of over 84.07% and low sheet resistance of 9.05 Ω/sq, and its quality factor can reach 218.2. Moreover, the transparent conductive film has an excellent folding performance. After 200 repeated folding experiments, the resistance change rate is only 7.8%. The heater prepared by using the composite film can reach a maximum heating temperature of 184.4 °C, and repeat the on-off operation several times under the condition of 55 °C, which proves the promising application of transparent conductive film in wearable devices for human bodies.