Conductivity Of Composite Films Research Articles

Controlled Distributed Ti3 C2 Tx Hollow Microspheres on Thermally Conductive Polyimide Composite Films for Excellent Electromagnetic Interference Shielding.

Flexible multifunctional polymer-based electromagnetic interference (EMI) shielding composite films have important applications in the fields of 5G communication technology, wearable electronic devices, and artificial intelligence. Based on the design of a porous/multilayered structure and using polyimide (PI) as the matrix and polymethyl methacrylate (PMMA) microspheres as the template, flexible (Fe3 O4 /PI)-Ti3 C2 Tx -(Fe3 O4 /PI) composite films with controllable pore sizes and distribution of Ti3 C2 Tx hollow microspheres are successfully prepared by sacrificial template method. Owing to the porous/multilayered structure, when the pore size of the Ti3 C2 Tx hollow microspheres is 10µm and the mass ratio of PMMA/Ti3 C2 Tx is 2:1, the (Fe3 O4 /PI)-Ti3 C2 Tx -(Fe3 O4 /PI) composite film has the most excellent EMI shielding performance, with EMI shielding effectiveness (EMI SE) of 85dB. It is further verified by finite element simulation that the composite film has an excellent shielding effect on electromagnetic waves. In addition, the composite film has good thermal conductivity (thermal conductivity coefficient of 3.49W (m·K)-1 ) and mechanical properties (tensile strength of 65.3MPa). This flexible (Fe3 O4 /PI)-Ti3 C2 Tx -(Fe3 O4 /PI) composite film with excellent EMI shielding performance, thermal conductivity, and mechanical properties has demonstrated great potential for applications in EMI shielding protection for high-power, portable, and wearable flexible electronic devices.

Electrical conductivity and corrosion resistance of Mo/Ti/Mn-based composite conversion films on AZ91D magnesium alloy

In this reported study, conductive composite conversion films on an AZ91D magnesium alloy were prepared by adding Ga3+ to a deposition solution that contained molybdenum, titanium and manganese ions. The Ga3+ significantly improved the conductivity and corrosion resistance of the resulting films. The electrical contact resistance (ECR) of the Molybdenum/Titanium/Manganese (MTM) film decreased from 0.436 Ω/in2 to 0.106 Ω/in2 at 200 psi when Ga3+ was added to form the Molybdenum-Titanium-Manganese-Gallium (MTMG) film. In addition, the polarization resistance of the Ga3+ amended film increased from 633.1 Ω·cm2 to 1930.835 Ω·cm2, MTMG showed obvious passivation behavior. The Ga3+ doping appeared to increase the carrier concentration and narrow the band gap of the semiconductor film. The N-type semiconductor carrier concentration increased from 2.11 × 1019 cm−3 to 7.052 × 1019 cm−3 in the MTMG film vs the MTM film. The P-type semiconductor carrier concentration in the MTMG film increased from 2.727 × 1018 cm−3 to 3.480 × 1019 cm−3 compared to the MTM film. The MTM band gap decreased from 2.916 eV to 2.714 eV in the MTMG film, which was attributed to the cross-doping of Ga3+ with transition metals in the MTMG material. The MTMG film had a three-layer structure, which preferentially formed a thin film on the β-phase and subsequently grew layer by layer.

Independent Heating Performances in the Sub-Zero Environment of MWCNT/PDMS Composite with Low Electron-Tunneling Energy

The structural stability of various structures (railroads, bridges, buildings, etc.) is lowered due to freezing because of the decreasing outside temperature in winter. To prevent damage from freezing, a technology for de-icing has been developed using an electric-heating composite. For this purpose, a highly electrically conductive composite film with multi-wall carbon nanotubes (MWCNTs) uniformly dispersed in a polydimethylsiloxane (PDMS) matrix through a three-roll process was fabricated by shearing the MWCNT/PDMS paste, through a two-roll process. The electrical conductivity and the activation energy of the composite were 326.5 S/m and 8.0 meV at 5.82 Vol% of MWCNTs, respectively. The dependence of the electric-heating performance (heating rate and temperature change) on the applied voltage and environmental temperature (from -20 °C to 20 °C) was evaluated. The heating rate and effective-heat-transfer characteristics were observed to decrease as the applied voltage increased, while they showed the opposite tendency when the environmental temperature was at sub-zero temperatures. Nevertheless, the overall heating performance (heating rate and temperature change) was maintained with little significant difference in the considered external-temperature range. The unique heating behaviors can result from the low activation energy and the negative-temperature (T) coefficient of resistance (R) (NTCR, dR/dT < 0) of the MWCNT/PDMS composite.

Conductive MoO3–PEDOT:PSS Composite Layer in MoO3/Au/MoO3–PEDOT:PSS Multilayer Electrode in ITO-Free Organic Solar Cells

The solution-processed and conductive MoO3–PEDOT:PSS (Mo–PPSS) composite layer in a MoO3/Au/MoO3–PEDOT:PSS (MoAu/Mo–PPSS) multilayer electrode in ITO-free organic solar cells (OSCs) was optimized in terms of electrical conductivity, interfacial contact quality, work function, and process wettability of the conductive composite thin film. The surface composition of the PEDOT:PSS film onto different electrodes was observed by using X-Ray Photoelectron Spectroscopy. The PEDOT:PSS-MoO3 composite protects the dissolution of individual MoO3 with PEDOT:PSS, which was confirmed by Auger Electron Spectroscopy. The UV-Visible spectroscopy showed that the photoactive layer of P3HT:PCBM absorbs in the wavelength range of 300–650 nm with the maximum absorption at 515 nm (2.40 eV). The device performance of 3.97% based on an MoAu/Mo–PPSS conductive composite electrode exhibited comparable enhancement and only 6% enhancement compared to an ITO-based electrode (3.91%). The enhancement of device efficiency was mainly due to relatively higher conductivity, a low work function of the conductive metal oxide-metal-metal oxide/polymer composite, and an enhancement of interfacial contact quality between the hole transport layer (HTL) and the mixed organic polymeric photoactive layer. These results indicate that the solution-processable Mo–PPSS conductive composite layer of the MoO3/Au multilayer electrode can replace the ITO-based electrode in the bulk of heterojunction organic photovoltaics (OPVs).

Phenylalanine-Assisted Conductivity Enhancement in PEDOT:PSS Films.

Biological materials such as amino acids are attractive due to their smaller environmental footprint, ease of functionalization, and potential for creating biocompatible surfaces for devices. Here, we report the facile assembly and characterization of highly conductive films of composites of phenylalanine, one of the essential amino acids, and PEDOT:PSS, a commonly used conducting polymer. We have observed that introducing aromatic amino acid phenylalanine into PEDOT:PSS to form composite films can improve the conductivity of the films by up to a factor of 230 compared to the conductivity of pristine PEDOT:PSS film. In addition, the conductivity of the composite films can be tuned by varying the amount of phenylalanine in PEDOT:PSS. Using DC and AC measurement techniques, we have determined that the conduction in the highly conductive composite films thus created is due to improvement in the electron transport efficiency compared to the charge transport in pure PEDOT:PSS films. Using SEM and AFM, we demonstrate that this could be due to the phase separation of PSS chains from PEDOT:PSS globules which can create efficient charge transport pathways. Fabricating composites of bioderived amino acids with conducting polymers using facile techniques such as the one we report here opens up opportunities for the development of low-cost biocompatible and biodegradable electronic materials with desired electronic properties.

Ultrathin Wood‐Derived Conductive Carbon Composite Film for Electromagnetic Shielding and Electric Heating Management

AbstractRecently, wood‐based composites have absorbed widespread concern in the field of electromagnetic interference (EMI) shielding due to their sustainability and inherent layered porous structure. The channel structure of wood is often used to load highly conductive materials to improve the EMI shielding performance of wood‐based composites. However, there is little research on how to use pure wood to prepare ultrathin EMI shielding materials. Herein, ultrathin veneer is obtained by cutting wood in parallel to the annual rings. Then, carbonized wood film (CWF) is prepared by a simple two‐step compressing and carbonization. The specific EMI shielding effectiveness (SSE/t) of CWF‐1200 with an ultrathin thickness (140 µm) and high electrical conductivity (58 S cm−1) can reach 9861.41 dB cm2 g−1, which is much higher than other reported wood‐based materials. In addition, the zeolitie imidazolate framework‐8 (ZIF‐8) nanocrystals are grown in situ on the surface of the CWF to obtain CWF/ZIF‐8. CWF/ZIF‐8 exhibits an EMI shielding effectiveness (SE) of up to 46 dB and an ultrahigh SSE/t value of 11 330.04 dB cm2 g−1 in X band. In addition, the ultrathin CWF also shows an excellent Joule heating effect. Therefore, the development of ultrathin wood‐based film provides a research basis for wood biomass to replace traditional non‐renewable and expensive electromagnetic (EM) shielding materials.

Photoactive and conductive biohybrid films by polymerization of pyrrole through voids in photosystem I multilayer films.

The combination of conducting polymers with electro- and photoactive proteins into thin films holds promise for advanced energy conversion materials and devices. The emerging field of protein electronics requires conductive soft materials in a composite with electrically insulating proteins. The electropolymerization of pyrrole through voids in a drop-casted photosystem I (PSI) multilayer film enables the straightforward fabrication of photoactive and conductive biohybrid films. The rate of polypyrrole (PPy) growth is reduced by the presence of the PSI film but is insensitive to its thickness, suggesting that rapid diffusion of pyrrole through the voids within the PSI film enables initiation at vacant areas on the gold surface. The base thickness of the composite tends to increase with time, as PPy chains propagate through and beyond the PSI film, coalescing to exhibit a tubule-like morphology as observed by scanning electron microscopy. Increasing amounts of PPy greatly increase the capacitance of the composite films in a manner almost identical to that of pure PPy films grown from unmodified gold, consistent with a high polymer/aqueous interfacial area and a conductive composite film. While PPy is not photoactive here, all composite films, including those with large amounts of PPy, exhibit photocurrents when irradiated by white light in the presence of redox mediator species. Optimization of the Py electropolymerization time is necessary, as increasing amounts of PPy lead to decreased photocurrent density due to a combination of light absorbance by the polymer and reduced accessibility of redox species to active PSI sites.

Nickel nanoparticle decorated silicon carbide as a thermal filler in thermal conductive aramid nanofiber-based composite films for heat dissipation applications.

Aramid nanofibers (ANFs) have shown potential applications in the fields of nanocomposite reinforcement, battery separators, thermal insulation and flexible electronics. However, the inherent low thermal conductivity limits the application of ANFs, currently, to ensure long lifetime in electronics. In this work, new nickel (Ni) nanoparticles were employed to decorate the silicon carbide (SiC) filler by a rapid and non-polluting method, in which nickel acetate tetrahydrate (Ni(CH3COO)2·4H2O) and SiC were mixed and heated under an inert atmosphere. The composites as thermal fillers were applied to prepare an aramid nanofiber (ANF)-based composite film. Our results showed that the decoration of SiC by an appropriate amount of Ni nanoparticles played an important role in improving the thermal conductivity, hydrophobicity, thermal stability, and puncture resistance of the ANF composite film. After adjusting the balling time at 10 h, the optimized content of 10 mol% Ni nanoparticles improved the thermal conductivity to 0.502 W m-1 K-1, 298.4% higher than that of the original ANF film. Moreover, increasing the content of thermal fillers to 30 wt% realized a high thermal conductivity of 0.937 W m-1 K-1, which is 643.7% higher than that of the pristine ANF film. Moreover, the compatibility between thermal fillers and ANFs and thermal stability were improved for the ANF-composite films. The effective heat transfer function of our composite films was further confirmed using a LED lamp and thermoelectric device. In addition, the obtained composite films show certain mechanical properties and better hydrophobicity; these results exhibit their great potential applications in electronic devices.

Structural modeling and calculation of thermal conductivity of polyimide composite materials

Issues of direct modeling effective thermal conductivity of two-component thermally conductive polyimide composite films based on polyimide thermosetting varnishes and thermally conductive powder fillers are considered.&#x0D; 3D-structural modeling of elementary cubic cells of polyimide composites has been performed.&#x0D; Calculations of average heat fluxes and effective thermal conductivity of variants of polyimide composite films with the introduction of highly thermally conductive highly dispersed and ultradispersed powder fillers into the polyimide matrix were carried out, including those from SiO2, SiC, Al2O3, AlN, taking into account boundary and initial conditions using COMSOL MULTIPHYSICS software.&#x0D; Specific recommendations are proposed for direct modeling of the thermal conductivity of environments with a complex structure and for carrying out with sufficient reliability numerical calculations of the effective thermal conductivity of polyimide composite films in order to increase their thermal conductivity from 0,12 W/(m•K) up to 1-4 W/(m•K) by changing concentration and thermal conductivity of mixtures of filler particles of micron and ultramicron sizes.

High sensitivity tactile sensors with ultrabroad linear range based on gradient hybrid structure for gesture recognition and precise grasping

Tactile sensors simultaneously with high sensitivity and ultrabroad linear range are crucial for skin-like dexterous manipulation of robots and prosthetics, which is not realized in previous research. Therefore, achieving linearity and high sensitivity simultaneously over a wide pressure range remains a major challenge. To solve this issue, a gradient pore/pyramid hybrid structured (GPPHS) conductive composite film is designed and fabricated with gradient compression characteristic and high structural compression properties, which show improved the sensitivity and extended the linear range. The GPPHS based tactile sensor reveals a high sensitivity of 40.12 kPa−1 over an ultrawide linearity range up to 1000 kPa, which is first largest linear range so far reported. Further, a gesture recognition smart glove, prosthetic hand tactile sensing system and a flexible sensing array based on GPPHS based tactile sensor are developed, and demonstrate unique gesture tracking characteristics, precise grasping ability and multi-touch sensing capacity.

Mechanically Enhanced Nanocrystalline Cellulose/Reduced Graphene Oxide/Polyethylene Glycol Electrically Conductive Composite Film.

Traditional conductive materials do not meet the increasing requirements of electronic products because of such materials' high rigidity, poor flexibility, and slow biodegradation after disposal. Preparing flexible conductive materials with excellent mechanical properties is an active area of research. The key to flexible conductive materials lies in the combination of the polymer matrix and conductive components. This combination can be achieved by making a film of renewable nano-microcrystalline cellulose (NCC) and reduced graphene oxide (rGO) with excellent electrical conductivity-by simple filtration and introducing polyethylene glycol (PEG) to enhance the functionality of the composite film. Graphene imparted conductivity to the composite film, which reached 5.67 S·m-1. A reinforced NCC/rGO/PEG-4 composite film with a thickness of only 21 μm exhibited a tensile strength of 30.56 MPa, which was 83% higher than that of the sample without PEG (16.71 MPa), and toughness of 727.18 kJ·m-3, which was about 132% higher than that of the control sample (NCC/rGO, 313.86 kJ·m-3). This ultra-thin conductive composite film-which can be prepared simply, consists of environmentally sustainable and biodegradable raw materials, and exhibits excellent mechanical properties-has substantial potential for applications in e.g., flexible electronic wearable devices, electrodes, and capacitors.

Multifunctional Thermally Conductive Composite Films Based on Fungal Tree‐like Heterostructured Silver Nanowires@Boron Nitride Nanosheets and Aramid Nanofibers

AbstractThermal conduction for electronic equipment has grown in importance in light of the burgeoning of 5G communication. It is imperatively desired to design highly thermally conductive fillers and polymer composite films with prominent Joule heating characteristics and extensive mechanical properties. In this work, “solvothermal &amp; in situ growth” method is carried out to prepare “Fungal tree”‐like hetero‐structured silver nanowires@boron nitride nanosheet (AgNWs@BNNS) thermally conductive fillers. The thermally conductive AgNWs@BNNS/ANF composite films are obtained by the method of “suction filtration self‐assembly and hot‐pressing”. When the mass fraction of AgNWs@BNNS is 50 wt%, AgNWs@BNNS/ANF composite film presents the optimal thermal conductivity coefficient of 9.44 W/(m ⋅ K) and excellent tensile strength of 136.6 MPa, good temperature‐voltage response characteristics, superior electrical stability and reliability, which promise a wide application potential in 5G electronic devices.

Multifunctional Thermally Conductive Composite Films Based on Fungal Tree-like Heterostructured Silver Nanowires@Boron Nitride Nanosheets and Aramid Nanofibers.

Thermal conduction for electronic equipment has grown in importance in light of the burgeoning of 5G communication. It is imperatively desired to design highly thermally conductive fillers and polymer composite films with prominent Joule heating characteristics and extensive mechanical properties. In this work, "solvothermal & in situ growth" method is carried out to prepare "Fungal tree"-like hetero-structured silver nanowires@boron nitride nanosheet (AgNWs@BNNS) thermally conductive fillers. The thermally conductive AgNWs@BNNS/ANF composite films are obtained by the method of "suction filtration self-assembly and hot-pressing". When the mass fraction of AgNWs@BNNS is 50 wt%, AgNWs@BNNS/ANF composite film presents the optimal thermal conductivity coefficient of 9.44 W/(m ⋅ K) and excellent tensile strength of 136.6 MPa, good temperature-voltage response characteristics, superior electrical stability and reliability, which promise a wide application potential in 5G electronic devices.

Acoustic-assisted 3D printing based on acoustofluidic microparticles patterning for conductive polymer composites fabrication

Multifunctional composites have been widely utilized in soft robots, electronics, batteries, and biomedicine. Meanwhile, several fabrication processes have been proposed to fabricate these functional composites with desired mechanical, electrical, magnetic, and thermal properties. However, patterning functional micro/nanomaterials such as particles, dots, wires, and fibers into complex designs with high spatial resolutions in a matrix remains a technical challenge. Herein, we present an acoustic-assisted 3D printing method enabled by standing surface acoustic waves (SSAWs). The proposed SSAWs-assisted patterning method produces diverse patterning forms of micro/nanomaterials and has almost no special requirements on micro/nanomaterials properties, indicating its great versatility and compatibility. Functional materials are assembled into desired stripe-like, net-like, and dot-like patterns. Multilayer composites with different patterns in each layer are even fabricated through a layer-by-layer printing process. To further demonstrate the potential of this 3D printing method, conductive polymer composite films with programmed electrical anisotropies are printed, yielding a maximum electrical conductivity of 827 S/m. The proposed acoustic-assisted patterning method makes the 3D printing of complex functional composites with customized properties possible, pushing the wide application of functional composites forward.

Studies of the Application of Electrically Conductive Composite Copper Films to Cotton Fabrics

This paper presents a technology for applying copper and silver films to cotton fabrics by combining photochemical and chemical methods for the reduction of the compounds of these metals. The resulting metal-containing films have inherent electrical conductivity of metals. All the main processes described in the work were carried out by means of the compounds being sorbed by the surface of the fabric when they were wetted in appropriate solutions. The aim of the work was to study the application of electrically conductive composite copper films on cotton fabrics. The tasks to achieve this aim were to perform scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction analysis to confirm that as a result of the experiment, CuCl with a semiconductor ability was formed on the surface of the sample. The driving force behind the photochemical reduction of copper and silver halides on cotton surfaces is that, as a result of the photooxidation of cellulose molecules in the fabric, copper monochloride is first formed on the cotton surface. Subsequently, the process of obtaining silver particles based on semiconductor silver chloride obtained as a result of the transformation of copper monochloride was carried out. The physicochemical and photochemical processes leading to the formation of monovalent copper chloride, which provides sufficient adhesion to the substrate, are considered. It is shown that in this case, the oxidation of monovalent copper also occurs with the formation of soluble salts that are easily removed by washing. Since the proposed technology does not require special equipment, and the chemical reagents used are not scarce, it can be used to apply bactericidal silver films to various household items and medical applications in ordinary laundries or at home. This article examines an affordable and simple technology for producing metal films on a cotton surface due to the presence of disadvantages (time duration, high temperature, scarce reagents, special installations, etc.) of a number of well-known methods in the production of chemical coatings.

Self-assembly strategy based on multiple hydrogen bonds for super tough, self-healing polyurethane elastomers

Focusing on the self-assembly strategy of polymer chain structure, designing and synthesizing intelligent, tough and healable polymer materials is an effective way to meet the high-end applications of materials. Inspired by spider silk, we designed a preparation scheme for a repairable polyurethane-polyurea elastomer (IPAD-6.4) with an unprecedented mechanical toughness of 625.10 MJ/m3 and elongation at break of 3756.56%. After repeated cyclic stretching, the elastic body can recover 92.85% of the dissipated energy in only 2 h. These results are achieved by the hierarchical hydrogen bonds formed by different groups and the reasonable covalent cross-linking network. Additionally, the elastomer shows excellent healing ability (repair efficiency ∼102.77%). A flexible conductive composite film is prepared by simple physical assembly. The sensor can not only accurately detect the bending motion of human joints, but also has excellent antibacterial properties, which gives the material application potential in medical and engineering fields.

A high ionic conductive PDOL/LAGP composite solid electrolyte film for Interfacial Stable solid-state lithium batteries

High ionic conductivity for solid electrolyte and stable electrode/electrolyte interface have always been the main requirements for solid-state lithium batteries. Herein, a high ionic conductive composite solid electrolyte (CSE) film was prepared by combining 1.3-dioxolanes (DOL) capable of in-situ polymerization with high ionic conductive Li1.5Al0.5Ge1.5(PO4)3 (LAGP)ceramic fillers. The CSE film also shows high interface compatibility and stability with lithium metal. The optimized poly-DOL (PDOL)-30% LAGP CSE exhibits a desirable dense and uniform structure, which endows the CSE with a high ion conductivity of 4.63 × 10−4 S cm−1, a high ion migration number up to 0.73 and a wide electrochemical stability window of 5.1 V. The assembled high-voltage NCM622/PDOL-30%LAGP CSE/Li solid-state cell exhibits good rate and cycle performances with a capacity of 125 mAh/g at 2 C and a capacity retention of 76% at 0.5C after 400 cycles with an average Coulomb efficiency of 99.7%. The PDOL-30%LAGP CSE also possesses a high inhibition ability of lithium dendrites owing to the dense and uniform structure and the stable electrolyte/lithium electrode interface including Li–Ge, LiF and CF3 components. The Li/CSE/Li cell maintains a relatively stable voltage up to 650 h at a current density of 0.1 mA/cm2. This high ionic conductive composite solid electrolyte film shows a good application prospect in high-voltage solid-state lithium batteries.

Highly thermally conductive, electrically insulated and flexible cellulose nanofiber-based composite films achieved via stereocomplex crystallites cross-linked graphene nanoplatelets

Synchronously achieving high thermal conductivity, electrical insulation and excellent mechanical properties in one flexible thermal management material is still a great challenge. In this work, a stereocomplex (SC) crystallites cross-linking method was developed to prepare the graphene nanoplatelets (GNPs) filled cellulose nanofibers (CNFs) composite films. The SC crystallites formed between adjacent GNPs exhibit the physical crosslinking effect, which not only prevents the transmission of electron while maintaining the heat diffusion ability in plane but also intensifies the interaction between GNPs to form the integrated GNP network in the whole composite films, endowing the composite films with excellent strength and toughness. As a consequence, the composite films with nacre-like structure exhibit high in-plane thermal conductivity (9.36 W m−1K−1) and high electrical insulation (3.1 × 109 Ω m) with extremely high stability during the repeated bending and heating/cooling measurements. Furthermore, the composite film containing 5 wt% filler exhibits an excellent tensile strength of 111.8 ± 6.1 MPa and high toughness of 24.5 ± 2.0 MJ m−3, which are 51.1% and 75.0% higher than those of the pure CNFs film, respectively. This work provides a valuable strategy for the fabrication of the CNFs-based composite films with promising properties that have great potential as the next-generation thermal management materials.

Tiny NaOH Assisted Facile Preparation of Silk Nanofibers and Their Nanotube-Compositing Strong, Flexible, and Conductive Films.

Natural silk nanofibers (SNFs) can not only be used as good building blocks for two- or three-dimensional biomaterials but also provide a clue for understanding the theory of structure-function relationships. Nevertheless, it is still difficult to directly extract SNFs from natural silk fibers due to their high crystallinity and recalcitrant complex structures. In the present study, a dilute alkali-assisted separation of high-yield SNFs is proposed. The degummed silk was first treated with a tiny amount of alkali at a mild temperature, followed by high-pressure homogenization. Under the optimized conditions (2% sodium hydroxide, 0 °C, 48 h), SNFs with diameters of 8-42 nm and lengths of 0.9 ± 0.3 μm were prepared with yields higher than 75%, which retained the natural structures at the nanoscale and some inherent properties of silk fibers. Interestingly, SNFs can be used as a stabilizing matrix to assist carbon nanotubes (CNTs) to disperse, aiming to form a uniform and stable CNT/SNF dispersion. Thereafter, a strong and flexible conductive composite film was fabricated with good mechanical properties. The composite film showed good piezoelectric properties and electric thermal response, which has promising application prospects for SNFs, such as in optical devices, nanoelectronics, and biosensors.

Weak Molecular Interactions in Organic Composite Dry Film Lead to Degradable, Robust Wireless Electrophysiological Signal Sensing

AbstractLong‐term and highly sensitive electrophysiological signal detection is the primary issue for wearable health monitoring. The critical issues of pre‐gelled wet electrodes as conventional approaches are limited conductivity and low adhesivity owing to the dependence of moisture concentration. Along this line, this paper presents a biocompatible, mechanically robust, water degradable, and intrinsically conductive organic composite dry film electrode based on poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), hydroxyethyl cellulose, and dopamine. The effects on PEDOT:PSS structure transition are studied systematically according to the combination of each component with various analytical methods including morphological, chemical, electrical, and mechanical characterization. The proposed film exhibits high conductivity (292 S m–1) and robust mechano‐electrical stability (only 8% of resistance change under 110 of fully flat‐bended cycles) owing to the weak but synergetic interactions between the components. Furthermore, low noise, clear signal, and long‐term stability for a wireless electrocardiogram and electromyogram signal sensing is achieved using the proposed dry electrode.