The emergence of wearable devices has spurred demand for strain sensors that are flexible, stretchable, and sensitive. Traditional strain sensors often lack stretchability due to the brittle nature ...of their materials. Conductive polymer composites (CPCs) are well-suited for this application due to their excellent flexibility, stretchability, and sensitivity, making them the material of choice for strain sensors. Resistive strain sensors, a common type of CPCs-based sensor, are favored for their cost-effectiveness, straightforward manufacturing process, and ease of signal collection. This review explores the sensing mechanisms of various resistive strain sensors, including percolation, crack propagation, contact resistance change and tunneling effect. It examines the impact of different fabrication processes and structural designs on sensor performance parameters including sensitivity, stretchability, linearity, and repeatability. Additionally, the advantages and challenges of integrating discrete sensors into high-density strain sensor arrays are discussed. Finally, we introduce the wide-ranging applications of CPCs-based strain sensors in multiple fields.
Display omitted
•Conductive polymer composites for resistive flexible strain sensors are introduced.•Four main sensing mechanisms for CPC-based resistive strain sensors are concluded.•Manufacturing and application of CPC-based strain sensors are discussed.•Challenges of making high-density strain sensor arrays are explained.
The Ni-rich LiNi
Co
Mn
O
(NCM
) cathode has attracted great interest owing to its low cost, high capacity, and energy density. Nevertheless, rapid capacity fading is a critical problem because of ...direct contact of NCM
with electrolytes and hence restrains its wide applications. To prevent the direct contact, the surface inert layer coating becomes a feasible strategy to tackle this problem. However, to achieve a homogeneous surface coating is very challenging. Considering the bonding effect between NCM
, polyvinylpyrrolidone (PVP), and polyaniline (PANI), in this work, we use PVP as an inductive agent to controllably coat a uniform conductive PANI layer on NCM
(NCM
@PANI-PVP). The coated PANI layer not only serves as a rapid channel for electron conduction, but also prohibits direct contact of the electrode with the electrolyte to effectively hinder side reaction. NCM
@PANI-PVP thus exhibits excellent cyclability (88.7% after 100 cycles at 200 mA g
) and great rate performance (152 mA h g
at 1000 mA g
). In situ X-ray diffraction and in situ Raman are performed to investigate the charge-discharge mechanism and the cyclability of NCM
@PANI-PVP upon electrochemical reaction. This surfactant-modulated surface uniform coating strategy offers a new modification approach to stabilize Ni-rich cathode materials for lithium-ion batteries.
Electrically conductive hydrogels (ECHs), combining electrical properties of metals or semiconductors with the unique features of hydrogels, are ideal frameworks to design and construct flexible ...supercapacitors and batteries. This review summarized the material design and synthetic approach of ECHs, demonstrating the advances of percolation theory in ECH materials, followed by presenting their effective application in flexible energy storage systems, and discussed the challenges and opportunities in this field.
Display omitted
To power wearable electronic devices, various flexible energy storage systems have been designed to work in consecutive bending, stretching and even twisting conditions. Supercapacitors and batteries have been considered to be the most promising energy/power sources for wearable electronics; however, they need to be electrochemically sustainable and mechanically robust. Electrically conductive hydrogels (ECHs), combining the electrical properties of conductive materials with the unique features of hydrogels, are ideal frameworks to design and construct flexible supercapacitors and batteries. ECHs are intrinsically flexible to sustain large mechanical deformation; they can hold a large amount of electrolyte solution in a 3D nanostructured conducting network, providing an extremely high surface area for the required electrochemical reactions. To date, nanostructured three-dimensional ECHs have exhibited high performance when applied as active electrode materials for supercapacitors and lithium-ion batteries. Future research may attempt to develop functional ECHs with controllable size, composition, morphology, and interface. This review summarizes the material design and synthetic approach of ECHs, demonstrating the advances of percolation theory in ECH materials, and subsequently presents their effective application in flexible energy storage systems and discusses the challenges and opportunities in this field.
Conductive polymer (CP) research has exploded in popularity over the years, with applications ranging from nanoelectronics to material science. CPs are, for all sorts of purposes, Nobel Prize‐winning ...compounds, as their inventors received the Nobel Prize in Chemistry in 2000. Conducting polymers have sparked a lot of interest in academic and industrial sectors because they combine the electrical characteristics of semiconductors and metals with the typical benefits of ordinary polymers, such as ease of preparation and low cost production. Conducting polymers have also received a lot of attention because of their unique characteristics, which include customizable electrical properties, excellent optical and mechanical capabilities, ease of synthesis and manufacturing, and superior environmental durability to traditional inorganic materials. In this study, the molecular structures and behaviors of the most common forms of CPs, namely, polyacetylene, polyaniline, polypyrrole, and polythiophene and derivatives of polythiophene are discussed. The transport phenomenon that allow to understand the conduction process, are also described in this review. An in‐depth investigation of conducting polymer‐based binary, ternary, and quaternary composites with carbon‐based materials, metal oxides, transition metals, and inorganic particles is utilized to analyze their applications as supercapacitors and batteries. There are also explanations of recent advancements in their applications in the areas of energy storage systems including batteries and supercapacitors. The development of their applications in the energy storage devices such as supercapacitors, lithium, and other ‐ions batteries, as well as their current issues and future prospect to advance energy storage systems are broadly discussed. This review is intended to contribute to a better understanding of this conducting polymer and, as a result, to the development of new research areas.
Display omitted
•A flexible supercapacitor with self-healing ability is fabricated.•Both electrode and electrolyte contain the same healable and tough hydrogel matrix.•The integrated all-hydrogel ...design enable the supercapacitor with great mechanical and electrochemical stability.•The supercapacitor can maintain stable energy output even after being subjected to various deformations.•The supercapacitor can heal itself within a short time after being broken.
Supercapacitors with multiple functions, such as high capacitance, high flexibility and self-healing properties, are capturing more and more attention in portable and wearable electronics. Herein, an all-hydrogel supercapacitor with multiple functions was fabricated, by sandwiching the polyaniline (PANI)-polyvinyl alcohol (PVA) hydrogel electrodes with a PVA-based hydrogel electrolyte which both contain the same healable and tough hydrogel matrix. The special efficient assembly between of PANI and PVA enables the hydrogel electrodes with superior electric conductivity of 136 S m−1 and large specific capacitance of 351 F g−1, as well as the great robustness and self-healing ability. The all-hydrogel supercapacitor exhibited a tensile strength of 2.21 MPa, a breaking elongation of 633%, a capacitance of 78.5 F g−1, and an energy density of 7.8 Wh kg−1. Due to its great toughness and flexibility, the supercapacitor could maintain stable energy output even after being subjected to various deformations (e. g., stretching, compressing, bending and even pinning). In addition, the severed supercapacitor could heal itself within 4 h at 70 °C, and the healed supercapacitor could restore good electrochemical properties with a healing efficiency of 49.8%. These highlighted properties enable this supercapacitor as a promising smart storage device for wearable application.
Ammonia (NH3) is one of the most abundant inorganic pollutants present in air. Efficient and rapid detection of ammonia is important to maintain the quality of air in both indoor as well as outdoor ...environment. Among various sensing principles, resistive sensing is a very popular option for the accurate detection of ammonia levels. Further, out of all the materials for sensing applications, polyaniline (PANI) is reported as a highly recommendable option for the construction of such sensing system. Specifically, the utility of PANI modifed by a facile electrospinning method has been demonstrated in the fabrication of efficient sensing systems for gaseous ammonia. This review was organized to offer insight into the potential utility of electrospinning approaches in the construction of PANI-based chemoresistive sensors for gaseous ammonia. The reliability of diverse electrospun PANI-based sensing systems for ammonia was assessed based on a comprehensive evaluation of their performance with respect to key sensing parameters (e.g., sensitivity, selectivity, response time, and limit of detection).
•The electrospinning can generate high quality polymers for versatile sensing applications.•PANI is one of the most suitable polymers for sensing gaseous ammonia.•Combination of electrospinning and PANI can fabricate high performance ammonia sensors.•PANI and its composite structures were developed through electrospinning for sensing NH3.•The PANI/TiO2 composite can show extremely low detectivity against NH3 such as 50 ppt.
Display omitted
•A flexible solid electrolyte sheet was obtained as a free-standing thin film (75 μm).•The electrolyte exhibited a high ionic conductance and good mechanical properties.•The solid ...lithium-ion cell with a solid electrolyte showed good cycling performance.
All-solid-state lithium batteries (ASSLBs) with solid electrolytes are promising battery systems capable of improving the safety and energy density of current lithium-ion batteries. Reducing the thickness of the solid electrolyte while preventing the short circuit between the anode and cathode is imperative to increase the energy density of ASSLBs. Sulfide-based solid electrolytes have high ionic conductivities; however, they are brittle, difficult to be processed into a thin film, and challenging to form stable interfaces with electrodes of large volume change. In this study, flexible thin-solid electrolyte sheets with Li+-ion conductive polymer network were prepared and characterized for ASSLB applications. They exhibited higher ionic conductance and superior mechanical properties than those of pristine Li6PS5X (argyrodite) pellets. The all-solid-state lithium-ion cell (graphite/LiNi0.7Co0.15Mn0.15O2) with a solid electrolyte sheet delivered a high discharge capacity of 182.5 mAh g−1 and showed good cycling stability at 0.33 C and 25 ℃, demonstrating that flexible and thin sheets are promising solid electrolytes for ASSLBs operating at room temperature.
•Conductive polymer composites with adhesion were prepared by a simple method.•This conducting polymer composites have excellent stability.•For the first time, we combined conductive polymers with 3D ...printed electrodes.•The sensor was used to determine chlorogenic acid in coffee solution.
The technology of 3D printing has emerged as a potent tool for the preparation of 3D-printed electrode. Using commercial graphene/polylactic acid (PLA) composite filaments as printed materials, fused deposition modeling as 3D-printed technique, 3D printed electrodes (3DEs) were created in this work. Gold nanoparticles (AuNPs) and the composites of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) were used to modify the activated 3DEs for constructing a novel electrode (SACP@Au@3DE), and in this work chlorogenic acid (CGA) was regarded as a probe for testing the performance of SACP@Au@3DE. The surface physicochemical properties of the prepared 3DEs were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The electrochemical properties of the prepared 3DEs were investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods. The constructed SACP@Au@3DE can be used to determine CGA at concentrations ranging from 10 to 400 μM with a limit of detection (LOD) of 4.13 μM. Ultimately, the SACP@Au@3DE sensor was used for CGA detection in coffee powder sample to explore the potential for real sample analysis. This work opens the novel avenue of using conductive polymer modified 3D-printed electrode in the field of sensor.
In this work, an electrochemical enzyme-linked oligonucleotide array to achieve simple and rapid multidetection of aflatoxin B1 (AFB1) is presented. The assay is based on a competitive format and ...disposable screen-printed cells (SPCs). Firstly, the electrodeposition of poly(aniline-anthranilic acid) copolymer (PANI-PAA) on graphite screen-printed working electrodes was performed by means of cyclic voltammetry (CV). Aflatoxin B1 conjugated with bovine serum albumin (AFB1-BSA) was then immobilized by covalent binding on PANI-PAA copolymer. After performing the affinity reaction between AFB1 and the biotinylated DNA-aptamer (apt-BIO), the solution was dropped on the modified SPCs and the competition was carried out. The biotinylated complexes formed onto the sensor surface were coupled with a streptavidin-alkaline phosphatase conjugate. 1-naphthyl phosphate was used as enzymatic substrate; the electroactive product was detected by differential pulse voltammetry (DPV). The response of the enzyme-linked oligonucleotide assay was signal-off, according to the competitive format. A dose-response curve was obtained between 0.1 ng mL−1 and 10 ng mL−1 and a limit of detection of 0.086 ng mL−1 was achieved. Finally, preliminary experiments in maize flour samples spiked with AFB1 were also performed.
Display omitted
•Electrochemical disposable array for aflatoxin B1 multianalysis.•Aptamer-based array was able to detect aflatoxin B1 in useful environmental range.•Aflatoxin B1 multidetection in food samples was realized.•Aptamer-based array results a fast and cost-effective device for screening multianalysis on field.
As a common antioxidant and nutritional fortifier in food chemistry, rutin has positive therapeutic effects against novel coronaviruses. Here, Ce-doped poly(3,4-ethylenedioxythiophene) (Ce-PEDOT) ...nanocomposites derived through cerium-based metal-organic framework (Ce-MOF) as a sacrificial template have been synthesized and successfully applied to electrochemical sensors. Due to the outstanding electrical conductivity of PEDOT and the high catalytic activity of Ce, the nanocomposites were used for the detection of rutin. The Ce-PEDOT/GCE sensor detects rutin over a linear range of 0.02–9 μM with the limit of detection of 14.7 nM (S/N = 3). Satisfactory results were obtained in the determination of rutin in natural food samples (buckwheat tea and orange). Moreover, the redox mechanism and electrochemical reaction sites of rutin were investigated by the CV curves of scan rate and density functional theory. This work is the first to demonstrate the combined PEDOT and Ce-MOF-derived materials as an electrochemical sensor to detect rutin, thus opening a new window for the application of the material in detection.
Display omitted
•The Ce-doped PEDOT was synthesized by Ce-MOF derivatization.•The rutin sensor based on Ce-PEDOT was constructed for the first time.•The Ce-PEDOT exhibited excellent electrocatalytic activity towards rutin.•The sensor shows high sensitivity and wide linear range for rutin.•The sensor has shown excellent performance in the analysis of natural foods.
PDF
