Multi-Layer Polyurethane-Fiber-Prepared Entangled Strain Sensor with Tunable Sensitivity and Working Range for Human Motion Detection.

The entanglement of fibers can form physical and topological structures, with the resulting bending and stretching strains causing localized changes in pressure. In this study, a multi-layer polyurethane-fiber-prepared (MPF) sensor was developed by coating the CNT/PU sensing layer on the outside of an elastic electrode through a wet-film method. The entangled topology of two MPFs was utilized to convert the stretching strain into localized pressure at the contact area, enabling the perception of stretching strain.

Large-Scale, Stretchable, Self-Protective, and Multifunctional Perovskite Luminescent Filament with Ultra-High Stability.

Lead halide perovskites possess great application potential in flexible displays and wearable optoelectronics owing to their prominent optoelectronic properties. However, the intrinsic instability upon moisture, heat, and ultraviolet (UV) light irradiation hinders their development and application. In this work, an ultra-stable CsPbX (X = Cl, Br, I) perovskite luminescent filament (PLF) with high stretchability (≈2400%) and luminescence performance (photoluminescence quantum yield (PLQY) of 24.

Photopolymerized multifunctional sodium alginate-based hydrogel for antibacterial and coagulation dressings.

Trauma caused by tissue damage in clinical applications has posed a serious threat to public safety. Dressings with a single function cannot meet the needs of wound healing, but multifunctional dressings are difficult to achieve and obtain. To address this issue, this research designed a facile one-pot photo-crosslinking method to prepare multifunctional sodium alginate-based hydrogel dressings for effective wound healing.

Construction Strategy for Flexible and Breathable SiO/Al/NFs/PET Composite Fabrics with Dual Shielding against Microwave and Infrared-Thermal Radiations for Wearable Protective Clothing.

Microwave and infrared-thermal radiation-compatible shielding fabrics represent an important direction in the development of wearable protective fabrics. Nevertheless, effectively and conveniently integrating compatible shielding functions into fabrics while maintaining breathability and moisture permeability remains a significant challenge. Here, we take hydrophilic PVA--PE nanofibrous film-coated PET fabric (NFs/PET) as a flexible substrate and deposit a dielectric/conductive (SiO/Al) bilayer film via magnetron sputtering.

Sculpting Mesoscopic Helical Chirality into Covalent Organic Framework Nanotubes from Entirely Achiral Building Blocks.

The diversification of chirality in covalent organic frameworks (COFs) holds immense promise for expanding their properties and functionality. Herein, we introduce an innovative approach for imparting helical chirality to COFs and fabricating a family of chiral COF nanotubes with mesoscopic helicity from entirely achiral building blocks for the first time. We present an effective 2,3-diaminopyridine-mediated supramolecular templating method, which facilitates the prefabrication of helical imine-linked polymer nanotubes using unprecedented achiral symmetric monomers.

N-Halamine-Based Polypropylene Melt-Blown Nonwoven Fabric with Superhydrophilicity and Antibacterial Properties for Face Masks.

Polypropylene melt-blown nonwoven fabric (PP MNF) masks can effectively block pathogens in the environment from entering the human body. However, the adhesion of surviving pathogens to masks poses a risk of human infection. Thus, embedding safe and efficient antibacterial materials is the key to solving pathogen infection.

Highly Conductive, Ultrastrong, and Flexible Wet-Spun PEDOT:PSS/Ionic Liquid Fibers for Wearable Electronics.

Conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) fibers with high electrical conductivity, flexibility, and robustness are urgently needed for constructing wearable fiber-based electronics. In this study, the highly conductive (4288 S/cm), ultrastrong (a high tensile strength of 956 MPa), and flexible (a low Young's modulus of 3.8 GPa) PEDOT:PSS/1-ethyl-3-methylimidazolium dicyanamide (EMIM:DCA) (P/ED) fiber was prepared by wet-spinning and a subsequent HSO-immersion-drawing process.

Silicon Distribution-Induced Actuation Film with Bidirectional Bending Deformation and Versatile Bionic Applications.

As an important branch of intelligent materials, the research and development of stimulus-responsive flexible intelligent actuation materials is of great significance to promote the industrialization of intelligent materials. In this study, the asymmetric PVA--PE/silicon nanoparticle (PPSN) composite films and PVA--PE/silicon sol (PPSS) composite film with different silicon distributions were prepared by a simple spraying method. The silicon nanoparticle layer in the PPSN composite film was similar to the sand-like water-absorbing layer, which can quickly absorb water and permeate it into the interior region, leading to the hygroscopic expansion behavior on one side of the nanofiber film.

Fiber based organic electrochemical transistor integrated with molecularly imprinted membrane for uric acid detection.

In this study, poly(3, 4-ethylenedioxythiophene) (PEDOT) nanocluster structure was synthesized on the reduced graphene oxide (rGO) modified cotton fibers. The organic electrochemical transistors based on the modified fiber have been assembled and their performance of different gate electrode transistors has been investigated. The transistor exhibits an excellent transconductance of up to 15.

Full-Textile Human Motion Detection Systems Integrated by Facile Weaving with Hierarchical Core-Shell Piezoresistive Yarns.

The tremendous progress of the wearable intelligent system has brought an urgent demand for flexible pressure sensors, especially for those possessing high sensing performances, simple manufacture technology, and efficient integration. In this work, hierarchical core-shell piezoresistive yarns (HCPYs), which contain internal silver-plated nylon electrodes and surface microporous structured carbon nanotubes (CNTs)/thermoplastic polyurethane (TPU) sensing layer, are designed and manufactured via facile wet-spinning accompanied by a water vapor coagulating bath. The obtained HCPY can either be inserted into traditional textiles to assemble a single-pressure sensor, or be woven into a textile-based flexible pressure sensors array with expected size and resolution, without compromising their comfort, breathability, and three-dimensional (3D) conformability.

Humidity-Driven Switch in the Transparency of a Nanofiber Film for a Smart Window.

Traditional smart windows use electrical signals to transform transparency. However, this electric transmission mode greatly limits their uses. Here, we have prepared a transparent PVA--PE/CA composite film, which can realize the reversible transformation of transparency under the stimulation of humidity.

Graphene Oxide/Nanofiber-Based Actuation Films with Moisture and Photothermal Stimulation Response for Remote Intelligent Control Applications.

The rapid development of intelligent technology and industry has induced higher requirements for multifunctional materials, especially intelligent materials with stimulus-responsive self-actuation behavior. In this study, a Cu@PVA-co-PE/GO composite actuation film, with an asymmetric sandwich structure, was prepared by attaching graphene oxide (GO) to the surface of a polyvinyl alcohol ethylene copolymer (PVA-co-PE) nanofiber composite film containing copper nanoparticles (Cu) through layer-on-layer adsorption. This unique structural design endowed the composite film with not only excellent structural stability but also different bending directions (in response to moisture and infrared light).

Fiber organic electrochemical transistors based on multi-walled carbon nanotube and polypyrrole composites for noninvasive lactate sensing.

Multi-walled carbon nanotubes (MWCNT) play a synergistic role with conducting polymer in practical applications such as biological sensing. In this paper, multi-walled carbon nanotube and polypyrrole (PPy) composites were prepared on a fiber surface for the first time, and their morphology and electrical properties were characterized. Compared with PPy-coated fiber, the presence of carbon nanotubes induced the growth of large areas of PPy nanowires.

Breathable and Large Curved Area Perceptible Flexible Piezoresistive Sensors Fabricated with Conductive Nanofiber Assemblies.

The rapid development of wearable electronics, humanoid robots, and artificial intelligence requires sensors to sensitively and stably detect external stress variations in large areas or on three-dimensional (3D) irregularly shaped surfaces while possessing the comfort. Most importantly, the flexibility and 3D compliance of sensors, and the fitting state of the interface between the sensor and the object are of great significance to the sensing accuracy and reliability. The ordered or random stacking and entangling of flexible and electrically conductive fiber materials can form a highly porous and mechanically stable fiber assembly.

Large-Area, Wearable, Self-Powered Pressure-Temperature Sensor Based on 3D Thermoelectric Spacer Fabric.

The rapid development of wearable devices puts forward higher requirements for mass-produced integrated smart systems that incorporate multiple electric components, such as energy supplying, multisensing, and communicating. To synchronously realize continuously self-powering, multifunctional sensing, distinguish signals from different stimuli, and productively design and fabricate a large-area sensing array, an all-fabric-based self-powered pressure-temperature-sensing electronic skin (e-skin) was prepared in this study by assembling highly flexible and compressible 3D spacer fabric (SF) and the thermoelectric poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (PEDOT:PSS). The all-fabric-based e-skin can efficiently and accurately sense the temperature with a detection resolution of 0.

Highly Accurate Wearable Piezoresistive Sensors without Tension Disturbance Based on Weaved Conductive Yarn.

Wearable piezoresistive sensors have attracted wide attention for application in human activities monitoring, smart robots, medical detection, etc. However, most of the sensing signals collected from the piezoresistive sensor are triggered by coupling forces, such as the combination of tension and pressure. Thus, the piezoresistive sensor would be incapable of accurately monitoring and evaluating specific human motion due to the mutual interference from tension and pressure, as the tension is difficult to be decoupled or eliminated from the coupling forces.

Flexible and Super-Sensitive Moisture-Responsive Actuators by Dispersing Graphene Oxide into Three-Dimensional Structures of Nanofibers and Silver Nanowires.

Smart actuators with excellent flexibility, sensitive responsiveness, large-scale bending-deformation, and rapid deformation-recovery performance have been sought after by researchers. Two-dimensional graphene oxide (GO) is considered as an ideal candidate for humidity-responsive actuators because of its excellent moisture sensitivity. Herein, a flexible membrane-based actuator was prepared by evenly dispersing GO sheets into a three-dimensional network formed by one-dimensional PVA--PE nanofibers (NFs) and silver nanowires (AgNWs).

Ultra-Sensitive Piezo-Resistive Sensors Constructed with Reduced Graphene Oxide/Polyolefin Elastomer (RGO/POE) Nanofiber Aerogels.

Flexible wearable pressure sensors have received extensive attention in recent years because of the promising application potentials in health management, humanoid robots, and human machine interfaces. Among the many sensory performances, the high sensitivity is an essential requirement for the practical use of flexible sensors. Therefore, numerous research studies are devoted to improving the sensitivity of the flexible pressure sensors.

Supported growth of inorganic-organic nanoflowers on 3D hierarchically porous nanofibrous membrane for enhanced enzymatic water treatment.

Organic-inorganic nanoflower is a new type of functional material that can effectively immobilize a wide range of enzymes to form flower-like structures for various enzymatic applications with enhanced catalytic performance and stability. In order to avoid the processing inconvenience and flower structure damage caused by the particular form of these hybrid nanoflowers during material fabrication and catalytic application, different substrates have been used to carry out supported growth of hybrid nanoflowers. However, all previously used substrates have only 2-dimensional feature and only incorporate hybrid nanoflowers on surface with limited nanoflower loading.

Photothermal and Moisture Actuator Made with Graphene Oxide and Sodium Alginate for Remotely Controllable and Programmable Intelligent Devices.

Functional materials with energy storage and conversion properties have been useful for actuating devices. Here, a new kind of torsional fiber-based actuator including graphene oxide (GO) and natural sodium alginate was prepared by traditional wet spinning and twisting methods, during which the fiber structure was reconstructed, and the mechanical energy was prestored. When the twisted GO/SA (graphene oxide/sodium alginate) fiber was stimulated by infrared light or moisture, the torsional structure of the fiber was activated instantaneously to generate rapid and reversible rotational motion, thus realizing the automatic release and re-storage process of rotational kinetic energy.

Strategy of Constructing Light-Weight and Highly Compressible Graphene-Based Aerogels with an Ordered Unique Configuration for Wearable Piezoresistive Sensors.

Three-dimensional (3D) graphene aerogels (GAs) have attracted huge attention from researchers due to their great potential in vast applications. The hydrothermal reaction combined with freeze-drying using graphene oxide (GO) as a precursor has proven to be an effective method for obtaining relatively well-structured pure GAs. However, insufficient mechanical strength and low compressibility of the materials still limit their practical applications.

Wearable Fiber-Based Organic Electrochemical Transistors as a Platform for Highly Sensitive Dopamine Monitoring.

Fiber-based organic electrochemical transistors (FECTs) provide a new platform for the realization of an ultrafast and ultrasensitive biosensor, especially for the wearable dopamine (DA)-monitoring device. Here, we presented a fully filament-integrated fabric, it exhibited remarkable mechanical compatibility with the human body, and the minimum sensing unit was an organic electrochemical transistor (OECT) based on PVA- co-PE nanofibers (NFs) and polypyrrole (PPy) nanofiber network. The introduction of NFs notably increased the specific surface area and hydrophilicity of the PA6 filament, resulting in the formation of a large area of intertwined PPy nanofiber network.

Ultrasensitive Wearable Pressure Sensors Assembled by Surface-Patterned Polyolefin Elastomer Nanofiber Membrane Interpenetrated with Silver Nanowires.

Wearable pressure sensors with ultrahigh sensitivity and flexibility have garnered tremendous attention because of their abilities to mimic the human somatosensory system and perceive surrounding pressure distribution. Herein, an ultrasensitive pressure sensor was fabricated with surface-patterned nanofibrous membranes (SPNMs) via a facile replica method from available plain-weaved nylon textiles. The SPNMs were composed of internal three-dimensional interpenetrating polyolefin elastomer nanofibers and silver nanowires (Ag NWs).

Multistimulus Responsive Actuator with GO and Carbon Nanotube/PDMS Bilayer Structure for Flexible and Smart Devices.

Smart devices with abilities of perceiving, processing, and responding are attracting more and more attentions due to the emerging development of artificial intelligent systems, especially in biomimetic and intelligent robotics fields. Designing a smart actuator with high flexibility and multistimulation responsive behaviors to simulate the movement of creatures, such as weight lifting, heavy objects carrying via simple materials, and structural design is highly demanded for the development of intelligent systems. Herein, a soft actuator that can produce reversible deformations under the control of light, thermal, and humidity is fabricated by combining high photothermal properties of CNT/PDMS layer with the natural hydrophilic GO layer.