Flexible Wearable Electronic Fabrics with Dual Functions of Efficient EMI Shielding and Electric Heating for Triboelectric Nanogenerators

Abstract

Traditional conductive fabrics are prepared by the synthesis of conductive polymers and the coating modification of metals or carbon black conductive materials. However, the conductive fabrics cause a significant decline in performance after washing or mechanical wear, which limits their application. Moreover, the single function of the traditional conductive fabric is also the reason that limits its wide application. In order to prepare a wearable, stable, high-performance, washable, multifunctional conductive fabric, we have carried out related research. In this work, polydopamine was used as a bonding layer, an adsorption reduction layer, and a protective layer to improve the bonding between silver nanoparticles and carbon nanotubes (CNTs) on the polyester fabric surface so as to prepare a multifunctional conductive fabric with a high-stability "sandwich" structure, in which a Ag-NPS@CNT structure acting as an intermediate conductive layer formed on the inner layer PDA@CNT by electroless silver plating and the outermost layer PDA@ CNT coated on the surface of the intermediate conductive layer by the impregnation-drying method. The sheet resistance of an E-Fabric can reach 2.11 Ω/□ due to the uniform and dense conductive path formed by the special structure Ag-NPs@CNT. At a low voltage of 1.5 V, the E-Fabric can reach 117 °C in 50 s and remain stable. The electrical conductivity and current heating properties of the E-Fabric remain good even after multiple washing or bending tests. Due to its stable and outstanding electrical conductivity, the E-Fabric has an electromagnetic shielding efficiency (SE T ) of 35.3 dB in the X-band (8.2−12.4 GHz). In addition, E-Fabricbased spin-coated poly(methyl methacrylate) or polydimethylsiloxane electrodes exhibit excellent performance in nanogenerators. Through the low-frequency friction of the human body, transient voltages up to 4 V can be generated from a 2 cm × 2 cm electrode sample. The output power of a single generator can reach about 12 nW/cm 2 . Therefore, an E-Fabric is considered to have great potential in the fields of electric heating, electromagnetic shielding, and smart wearable devices.

Carbon Nanofibrous Aerogels Derived from Electrospun Polyimide for Multifunctional Piezoresistive Sensors

“…Flexible wearable electronic devices are widely used in various fields, which puts forward the demand of multifunctional integration. In order to meet the practical application needs of people in cold areas such as aviation, aerospace, and alpine regions for multifunctional wearable electronic devices, thermal conversion ability has become an essential feature. , In addition to excellent sensing and EMI shielding performance, the high electrical conductivity also endows PI-CNA aerogels with excellent Joule heating performance, which could be applied as wearable heaters for soldiers and pregnant women (Figure a). To investigate the electrothermal performance, a test device was designed using the PI-CNA aerogel.…”

Fabrics Modified with Ag Nanowire/Cellulose Nanofibril Composites for High Conductivity, Electromagnetic Interference Shielding, Ultraviolet Protection, and Thermal Insulation

“…Textile products with a wide range of applications have recently attracted considerable attention along with the development of corresponding technological innovation and growing consumer demands because of their flexibility, machinability, and wearable properties. , Recently, modified fabrics have been reported to show encouraging properties such as EMI shielding, UV protection, thermal insulation, antibacterial, water transport, and other wearable effects and applications. − However, the stability and durability of the modifications remain challenging, particularly in special working environments like underwater, high temperature, light, and fatigue environments. − …”

Carbonized Syndiotactic Polystyrene/Carbon Nanotube/MXene Hybrid Aerogels with Egg-Box Structure: A Platform for Electromagnetic Interference Shielding and Solar Thermal Energy Management

“…Electromagnetic interference (EMI) shielding materials, including carbon aerogels, , metallic materials, composite foams, , polymeric composites, − and cementitious composites, are booming. These materials possess high electrical conductivity, which plays a critical role to achieve high EMI shielding effectiveness (SE). − Moreover, the topological structure can significantly affect the materials’ EMI SE, for example, the gradient and/or sandwich structures were demonstrated to enhance the effectiveness by facilitating multiple reflections between parallel reflective planes. ,,, …”