The rapid improvement in the running speed, transmission efficiency, and power density of miniaturized devices means that multifunctional flexible composites with excellent thermal management capability and high electromagnetic interference (EMI) shielding performance are urgently required. Here, inspired by the fibrous pathways of the human nervous system, a “core–sheath” fibers structured strategy was proposed to prepare thermoplastic polyurethane/polydopamine/carbon nanotube (TPU/PDA/CNT) composites film with thermal management capability and EMI shielding performance. Firstly, TPU@PDA@CNT fibers with CNT shell were prepared by a facile polydopamine-assisted coating on electrospun TPU fibers. Subsequently, TPU/PDA/CNT composites with three-dimensional (3D) fibrous CNT “tracks” are obtained by a hot-pressing process, where CNTs distributed on adjacent fibers are compactly contacted. The fabricated TPU/PDA/CNT composites exhibit a high in-plane thermal conductivity (TC) of 9.6 W/(m·K) at low CNT loading of 7.6 wt.%. In addition, it also presents excellent mechanical properties and excellent EMI shielding effectiveness of 48.3 dB as well as multi-source driven thermal management capabilities. Hence, this study provides a simple yet scalable technique to prepare composites with advanced thermal management and EMI shielding performance to develop new-generation wireless communication technologies and portable intelligent electronic devices.

The strategy of incorporating polymers into MXene-based functional materials has been widely used to improve their mechanical properties, however with inevitable sacrifice of their electrical conductivity and electromagnetic interference (EMI) shielding performance. This study demonstrates a facile yet efficient layering structure design to prepare the highly robust and conductive double-layer Janus films comprised of independent aramid nanofiber (ANF) and Ti₃C₂T_x MXene/poly(3,4-ethylenedioxy- thiophene):poly(styrenesulfonate) (PEDOT:PSS) layers. The ANF layer serves to provide good mechanical stability, whilst the MXene/PEDOT:PSS layer ensures excellent electrical conductivity. Doping PEDOT:PSS into the MXene layer enhances the interfacial bonding strength between the MXene and ANF layers and improves the hydrophobicity and water/oxidation resistance of MXene layer. The resultant ANF/MXene-PEDOT:PSS Janus film with a conductive layer thickness of 4.4 μm was shown to display low sheet resistance (2.18 Ω/sq), good EMI shielding effectiveness (EMI SE of 48.1 dB), high mechanical strength (155.9 MPa), and overall toughness (19.4 MJ/m³). Moreover, the excellent electrical conductivity and light absorption capacity of the MXene-PEDOT:PSS conductive layer mean that these Janus films display multi-source driven heating functions, producing excellent Joule heating (382 °C at 4 V) and photothermal conversion (59.6 °C at 100 mW/m²) properties.

Flexible pressure sensors have attracted wide attention due to their applications to electronic skin, health monitoring, and human-machine interaction. However, the tradeoff between their high sensitivity and wide response range remains a challenge. Inspired by human skin, we select commercial silicon carbide sandpaper as a template to fabricate carbon nanotube (CNT)/polydimethylsiloxane (PDMS) composite film with a hierarchical structured surface (h-CNT/PDMS) through solution blending and blade coating and then assemble the h-CNT/PDMS composite film with interdigitated electrodes and polyurethane (PU) scotch tape to obtain an h-CNT/PDMS-based flexible pressure sensor. Based on in-situ optical images and finite element analysis, the significant compressive contact effect between the hierarchical structured surface of h-CNT/PDMS and the interdigitated electrode leads to enhanced pressure sensitivity and a wider response range (0.1661 ​kPa⁻¹, 0.4574 ​kPa⁻¹ and 0.0989 ​kPa⁻¹ in the pressure range of 0–18 ​kPa, 18–133 ​kPa and 133–300 ​kPa) compared with planar CNT/PDMS composite film (0.0066 ​kPa⁻¹ in the pressure range of 0–240 ​kPa). The prepared pressure sensor displays rapid response/recovery time, excellent stability, durability, and stable response to different loading modes (bending and torsion). In addition, our pressure sensor can be utilized to accurately monitor and discriminate various stimuli ranging from human motions to pressure magnitude and spatial distribution. This study supplies important guidance for the fabrication of flexible pressure sensors with superior sensing performance in next-generation wearable electronic devices.