The rapid development of portable/wearable electronics proposes new demands for energy storage devices, which are flexibility, smart functions and long-time outdoor operation. Supercapacitors (SCs) show great potential in portable/wearable applications, and the recently developed flexible, smart and self-sustainable supercapacitors greatly meet the above demands. In these supercapacitors, conductive polymers (CPs) are widely applied due to their high flexibility, conductivity, pseudo-capacitance, smart characteristics and moderate preparation conditions. Herein, we'd like to introduce the CP-based flexible, smart and self-sustainable supercapacitors for portable/wearable electronics. This review first summarizes the flexible SCs based on CPs and their composites with carbon materials and metal compounds. The smart supercapacitors, i.e., electrochromic, electrochemical actuated, stretchable, self-healing and stimuli-sensitive ones, are then presented. The self-sustainable SCs which integrate SC units with energy-harvesting units in one compact configuration are also introduced. The last section highlights some current challenges and future perspectives of this thriving field.

Designing flexible, smart and self-sustainable supercapacitors for portable/wearable electronics: from conductive polymers

Multifunctional RGO/Ti3C2Tx MXene fabrics for electrochemical energy storage, electromagnetic interference shielding, electrothermal and human motion detection

Multifunctional wearable strain/pressure sensor based on conductive carbon nanotubes/silk nonwoven fabric with high durability and low detection limit

Preparation of smart and reversible wettability cellulose fabrics for oil/water separation using a facile and economical method.

Accurate and real‐time detection of human body temperature changes is crucial to understand thermal homeostasis, to access complex health conditions, and to further build a smart healthcare system. Recent years have seen temperature sensors open up many potential applications in electronic skin, artificial intelligence, and next‐generation smart robots. Currently, traditional mercury and infrared thermometers are extensively used for human body temperature detection. However, they still suffer from rigid appearance, slow response, insufficient sensitivity, low accuracy, and potential harm risk to the users. Therefore, it is highly desired to develop more breathable, deformable, and economically available functional materials to construct the flexible high performance temperature sensors. Alternatively, fiber materials have attracted more attention owing to their soft, flexible, deformable, and porous features. This review summarizes a comprehensive research advancement in the field of flexible temperature sensors constructed with fiber materials. Temperature sensing mechanisms, functional constructing materials, performance characterizations, practical applications, and fiber‐based temperature sensors with different structural designs are systematically introduced at great length. Research outlook and prospects will be presented to inspire the potential readers.

Flexible Temperature Sensors Constructed with Fiber Materials

An effective surface modification of polyester fabrics for improving the interfacial deposition of polypyrrole layer

Multi-walled carbon nanotubes functionalized silk fabrics for mechanical sensors and heating materials

Ramie fabric has excellent air permeability and moisture absorption, but the scratchiness caused by hairiness has seriously limited the development of ramie in the apparel field. In this paper, we studied a novel surface micro-dissolution method, which can swell cellulose macromolecules on the surface zone of ramie fabric and eliminate hairiness to decrease scratchiness. Surface micro-dissolution was conducted in the presence of sodium hydroxide/urea (NaOH/urea) aqueous system as an effective cellulose solvent at low temperature. Scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry were used to investigate the morphology and structure of treated ramie fabrics. Hairiness configuration, breaking strength, whiteness, and moisture sorption of the fabrics were also studied. The results indicated that surface micro-dissolution could effectively eliminate hairiness, and the fabric's tension decreased only slightly. In addition, whiteness and moisture sorption was also maintained.

Surface micro-dissolution of ramie fabrics with NaOH/urea to eliminate hairiness

Incorporation of PANI with polyethylene terephthalate (PET) fibers has creates many flexible conductive, electrothermal and energy-storage textiles. The most common method of depositing PANI to PET fibers is in-situ polymerization. However, it usually needs long reaction time and strict conditions, which is unbeneficial to large-scale commercialized process. Herein, a facile and high-efficiency surface micro-dissolution method was proposed to prepare PANI-coated PET fabrics, which is performed at moderate temperature (70 °C) and only needs 15 min of treatment time. Already-made PANI powders were directly used as raw materials, and the phenol/N-methyl pyrrolidone (phenol/NMP) solution worked as the surface micro-dissolution agent. The resulting fabrics show electroconductive (620 Ω/□), electrothermal (from 22.3–30.3 ℃ within 1 min) and energy storage (438.51 m F cm−2) performances. The preparation is easy to perform and of very high efficiency, making it suitable for industrial production of PANI-coated PET fabrics.

Zhou Jing

Papers

An effective surface modification of polyester fabrics for improving the interfacial deposition of polypyrrole layer

Multi-walled carbon nanotubes functionalized silk fabrics for mechanical sensors and heating materials

Surface micro-dissolution of ramie fabrics with NaOH/urea to eliminate hairiness

Creation of polyaniline-coated polyester fabrics with conductive, electrothermal and energy-storage properties via micro-dissolution method

Ultrasound assisted surface micro-dissolution to embed nano TiO2 on cotton fabrics in ZnCl2 aqueous solution.