Biomimetic Fibrous Murray Membranes with Ultrafast Water Transport and Evaporation for Smart Moisture-Wicking Fabrics

Directional Moisture-Wicking Triboelectric Materials Enabled by Laplace Pressure Differences

Wearable sensors are experiencing vibrant growth in the fields of health monitoring systems and human motion detection, with comfort becoming a significant research direction for wearable sensing devices. However, the weak moisture-wicking capability of sensor materials leads to liquid retention, severely restricting the comfort of the wearable sensors. This study employs a pattern-guided alignment strategy to construct microhill arrays, endowing triboelectric materials with directional moisture-wicking capability. Within 2.25 s, triboelectric materials can quickly and directionally remove the droplets, driven by the Laplace pressure differences and the wettability gradient. The directional moisture-wicking triboelectric materials exhibit excellent pressure sensing performance, enabling rapid response/recovery (29.1/37.0 ms), thereby achieving real-time online monitoring of human respiration and movement states. This work addresses the long-standing challenge of insufficient moisture-wicking driving force in flexible electronic sensing materials, holding significant implications for enhancing the comfort and application potential of electronic skin and wearable electronic devices.

Microfluidic Sensing Textile for Continuous Monitoring of Sweat Glucose at Rest

Wearable sweat sensors have received considerable attention due to their great potential for noninvasive continuous monitoring of an individual's health status applications. However, the low secretion rate and fast evaporation of sweat pose challenges in collecting sweat from sedentary individuals for noninvasive analysis of body physiology. Here, we demonstrate wearable textiles for continuous monitoring of sweat at rest using the combination of a heating element and a microfluidic channel to increase localized skin sweat secretion rates and combat sweat evaporation, enabling accurate and stable monitoring of trace amounts of sweat. The Janus sensing yarns with a glucose sensing sensitivity of 36.57 mA cm-2 mM-1 are embroidered into the superhydrophobic heated textile to collect sweat directionally, resulting in improved sweat collection efficiency of up to 96 and 75% retention. The device also maintains a highly durable sensing performance, even in dynamic deformation, recycling, and washing. The microfluidic sensing textile can be further designed into a wireless sensing system that enables sedentary-compatible sweat analysis for the continuous, real-time monitoring of body glucose levels at rest.

Wettability Gradient-Induced Diode: MXene-Engineered Membrane for Passive-Evaporative Cooling

Thermoregulatory textiles, leveraging high-emissivity structural materials, have arisen as a promising candidate for personal cooling management; however, their advancement has been hindered by the underperformed water moisture transportation capacity, which impacts on their thermophysiological comfort. Herein, we designed a wettability-gradient-induced-diode (WGID) membrane achieving by MXene-engineered electrospun technology, which could facilitate heat dissipation and moisture-wicking transportation. As a result, the obtained WGID membrane could obtain a cooling temperature of 1.5 °C in the "dry" state, and 7.1 °C in the "wet" state, which was ascribed to its high emissivity of 96.40% in the MIR range, superior thermal conductivity of 0.3349 W m-1 K-1 (based on radiation- and conduction-controlled mechanisms), and unidirectional moisture transportation property. The proposed design offers an approach for meticulously engineering electrospun membranes with enhanced heat dissipation and moisture transportation, thereby paving the way for developing more efficient and comfortable thermoregulatory textiles in a high-humidity microenvironment.

Thermoresponsive Skin-like Fabric for Personal Comfort and Protection

Acting as a "second skin", clothing plays an indispensable role in providing comfort and protection in the wide range of environments in which we live. However, comfort and protection are often competing requirements and are difficult to improve simultaneously. By mimicking the exceptional thermoresponsive one-way liquid transport property of human skin, here we developed a scalable and ecofriendly skin-like fabric that has a tunable directional water transport rate while having excellent water repellency. The water transport rate is also temperature-responsive, just like skin. As the temperature increases, the wettability gradient in the spatially distributed channels (acting like "sweat glands") increases, promoting sweat transport and evaporative heat dissipation. As the temperature decreases, on the other hand, the wettability gradient diminishes, reducing liquid transport and evaporative heat loss, thereby promoting heat retention. The fabric is highly suitable for sportswear and functional clothing and can have wider applications, such as oil-water separation, fog harvesting, etc.

Tetrapodal textured Janus textiles for accessible menstrual health

Menstruating individuals without access to adequate hygiene products often improvise with alternatives that pose health risks and limit their participation in society. We describe here a menstrual hygiene product based on low-cost materials, which are integrated onto fabrics to imbue unidirectional permeability. A body-facing "Janus" fabric top layer comprising ZnO tetrapods spray-coated onto polyester mosquito netting imparts hierarchical texturation, augmenting the micron-scale texturation derived from the weave of the underlying fabric. The asymmetric coating establishes a gradient in wettability, which underpins flash spreading and unidirectional permeability. The hygiene product accommodates a variety of absorptive media, which are sandwiched between the Janus layer and a second outward-facing coated densely woven fabric. An assembled prototype demonstrates outstanding ability to wick saline solutions and a menstrual fluid simulant while outperforming a variety of commercially alternatives. The results demonstrate a versatile menstrual health product that provides a combination of dryness, discretion, washability, and safety.

Sweat Gland-Inspired Skin-like Fabric with Directional Water Transport and Durability for Efficient Personal Moisture Management

Directional water transport textiles are an energy-free approach to improving the comfort of the human body. However, existing strategies mainly focus on enhancing the capacity of directional water transport, complicating the preparation process and limiting the long-term durability of textiles. Herein, a skin-like fabric inspired by sweat glands was prepared in one step by patterning printed hydrophobic paste on the fabric. This skin-like fabric has achieved the desired one-way water transport index (R, 721%), air permeability of 104 mm s-1, and water vapor transmission rate (298 g m-2 h-1). More significantly, due to the strong chemical bonds between the fabric and the coating, the skin-like fabric exhibited a high weight retention of 99.4% after 400 abrasion cycles and stable performance (R, 658%) after 25 h of washing. This work proposes a reliable way to prepare high-performance fabrics with durability, which show great potential for applications in functional textiles for personal moisture management.

Asymmetric Multienergy-Coupled Radiative Warming Textiles for Personal Thermal-Moisture Management

In order to address the requirements for warmth and energy conservation in cold climates, the development of personal thermal management textiles that regulate local human thermal comfort has emerged as a promising solution in recent times. Nevertheless, existing warming textile strategies often rely on a singular energy source, exhibit inadequate air/moisture permeability, and lack adaptability to dynamic and intricate climate variations. Herein, a novel multienergy-coupled radiative warming Janus textile has been effectively designed and fabricated via screen printing and foam finishing. Taking advantage of the synergistic effects of directional water transport capability of polyester-covered cotton (with a directional water-transport index of R = 577.5%), high mid-infrared radiant reflection (at 60%), electrothermal conversion of copper coating (with a sheet resistance of 0.01 Ω sq-1), and strong solar absorption of the nanoporous structure TA@APTES@Fe(III)@CNT (TAFC) coating (at 98.5%), the Janus fabric exhibits exceptional performance in expelling out one-way sweat/moisture (R = 329.3%) and solar heating (86.9 °C)/Joule heating (226.4 °C at 3.0 V)/heat retention (2.4 °C higher than that of cotton fabric). Furthermore, the fabric is also provided with exceptional mechanical, washing, flame-retardant, and antibacterial performance. This research holds the potential to revolutionize the development and production of warming textiles by incorporating desirable sweat/moisture permeability and multienergy-coupled heating.

Sweat and odor in sportswear - A review

Sportswear worn next to the skin is easily soaked by sweat and may become a breeding ground for the microbiome, thus a source of malodor. Malodor can cause social embarrassment and discomfort to both wearer and others. Given the risks current deodorant products pose to nature and human life, the development of sustainable textiles for odor control comes to the forefront. This review introduces the odor-generating mechanism in clothing from the perspectives of perspiration composition and cutaneous microbiome. With the knowledge of the significant role of sweat in odor formation, the sweat distribution of the human body, measurement techniques, and advanced technologies developed for quick-dry function are presented in the second part. Lastly, odor management in sportswear is evaluated, covering the odor-assessing techniques, the effects of various textile materials, and emerging solutions in terms of antibacterial treatment, adsorbent materials, and photocatalytic degradations of odorous compounds. Overall, it is of both personal and social value to develop novel textile materials with odor-control functions by making use of natural materials and fabric designs.

Biomimetic polymer fibers-function by design

Biomimicry applies the fundamental principles of natural materials, processes, and structures to technological applications. This review presents the two strategies of biomimicry-bottom-up and top-down approaches, using biomimetic polymer fibers and suitable spinning techniques as examples. The bottom-up biomimicry approach helps to acquire fundamental knowledge on biological systems, which can then be leveraged for technological advancements. Within this context, we discuss the spinning of silk and collagen fibers due to their unique natural mechanical properties. To achieve successful biomimicry, it is imperative to carefully adjust the spinning solution and processing parameters. On the other hand, top-down biomimicry aims to solve technological problems by seeking solutions from natural role models. This approach will be illustrated using examples such as spider webs, animal hair, and tissue structures. To contextualize biomimicking approaches in practical applications, this review will give an overview of biomimetic filter technologies, textiles, and tissue engineering.

Locking Patterned Carbon Nanotube Cages by Nanofibrous Mats to Construct Cucurbituril[n]-Based Ultrapermselective Dye/Salt Separation Membranes

Surface patterning is a promising strategy to overcome the trade-off effect of separation membranes. Herein, a bottom-up patterning strategy of locking micron-sized carbon nanotube cages (CNCs) onto a nanofibrous substrate is developed. The strongly enhanced capillary force triggered by the abundant narrow channels in CNCs endows the precisely patterned substrate with excellent wettability and antigravity water transport. Both are crucial for the preloading of cucurbit[n]uril (CB6)-embeded amine solution to form an ultrathin (∼20 nm) polyamide selective layer clinging to CNCs-patterned substrate. The CNCs-patterning and CB6 modification result in a 40.2% increased transmission area, a reduced thickness, and a lowered cross-linking degree of selective layer, leading to a high water permeability of 124.9 L·m^-2 h^-1 bar^-1 and a rejection of 99.9% for Janus Green B (511.07 Da), an order of magnitude higher than that of commercial membranes. The new patterning strategy provides technical and theoretical guidance for designing next-generation dye/salt separation membranes.

Recent Advances in Thermoregulatory Clothing: Materials, Mechanisms, and Perspectives

Personal thermal management (PTM) is a promising approach for maintaining the thermal comfort zone of the human body while minimizing the energy consumption of indoor buildings. Recent studies have reported the development of numerous advanced textiles that enable PTM systems to regulate body temperature and are comfortable to wear. Herein, recent advancements in thermoregulatory clothing for PTM are discussed. These advances in thermoregulatory clothing have focused on enhancing the control of heat dissipation between the skin and the localized environment. We primarily summarize research on advanced clothing that controls the heat dissipation pathways of the human body, such as radiation- and conductance-controlled clothing. Furthermore, adaptive clothing such as dual-mode textiles, which can regulate the microclimate of the human body, as well as responsive textiles that address both thermal performance (warming and/or cooling) and wearability are discussed. Finally, we include a discussion on significant challenges and perspectives in this field, including large-scale production, smart textiles, bioinspired clothing, and AI-assisted clothing. This comprehensive review aims to further the development of sustainably manufactured advanced clothing with superior thermal performance and outstanding wearability for PTM in practical applications.

Plant-Mimetic Vertical-Channel Hydrogels for Synergistic Water Purification and Interfacial Water Evaporation

The integration of renewable solar energy-driven interfacial evaporation and photocatalysis has recently emerged as one of the most promising technologies for simultaneous freshwater production and pollutant removal. However, the construction of an advanced integrated system with the merit of a fast supply of water and pollutant molecules remains challenging for efficient solar-driven evaporation and photocatalytic performance. Herein, inspired by the transpiration of plants, we fabricate a biomimetic, vertically channeled polypyrrole/foam-like carbon nitride/poly(vinyl alcohol) hydrogel (PCH) by directional freeze-drying. We prove that the vertically aligned channels not only reduce heat loss and improve energy conversion efficiency but also facilitate the transport of water and organic pollutants to the air-water interface. Benefiting from the advantages above, the PCH evaporator presents a high solar evaporation efficiency of 92.5%, with the evaporation rate achieving 2.27 kg m^-2 h^-1 under 1 kW m^-2 irradiation, exceeding many advanced interfacial solar-driven evaporators. Meanwhile, PCH reaches a degradation efficiency of 90.6% within 1 h when dealing with tetracycline (a typical antibiotic)-polluted water, remarkably higher than that of the hydrogel without vertically aligned channels (68.6%). Furthermore, the as-formed reactive oxygen species effectively kill Gram-positive and Gram-negative bacterial in the source water, achieving the all-round water purification. In an outdoor experiment, after 11 h of sunlight irradiation, the tetracycline degradation efficiency and freshwater production of the PCH evaporator rise to 99.0% and 6.2 kg m^-2, respectively. This work highlights the novel biomimetic approach to fabricate multifunctional photothermal materials for simultaneous freshwater production and polluted-water remediation.

Highly Breathable and Abrasion-Resistant Membranes with Micro-/Nano-Channels for Eco-Friendly Moisture-Wicking Medical Textiles

One-way water transport is a predominant feature of comfortable textiles used in daily life. However, shortcomings related to the textiles include their poor breathability and durability. In this study, low-cost and eco-friendly PLA/low-melt (polylactic acid) LMPLA-thermoplastic polyurethane (TPU) membranes were fabricated through a needle punch/hot press and electrospinning method. The micro-/nano-channels, used for the first time, endowed the composite membranes with robust, breathable, moisture-permeable, and abrasion-resistant performance. By varying the nano- layer thickness, the resulting 16-40 μm membranes exhibited excellent one-way water transport, robust breathability and moisture permeability, and good abrasion resistance. Nano-layer thickness was found to be a critical performance factor, balancing comfort and protection. These results may be useful for developing low-cost, eco-friendly, and versatile protective products for medical application.

Biomimetic Fibrous Leaf-Vein Membrane Enabling Unidirectional Water Penetration and Effective Antibacterial PM Filtration

Air pollution induced by pathogenic particulate matter (PM) has posed a serious threat to public health worldwide. Advanced air filters are thus required, not only exhibiting high PM capture efficiency, low breathing resistance, and high internal moisture transferring performance but also isolating and inactivating external pathogenic aerosols. In this study, we demonstrated a facile approach to construct a biomimetic fibrous leaf-vein membrane with unidirectional water penetration and effective antibacterial PM filtration by one-step electrospinning of poly(vinylidene fluoride) (PVDF)-based multilayer nanofibers. With ultrathin fibers penetrating the skeletal framework of bimodal thick fibers, the membranes showed gradient interconnected porous structures and achieved a highly efficient and stable (in an acid and alkali environment) PM_0.3 interception (>99.98%) with low air drag (51-71 Pa). In addition, the gradient narrow pores of the membranes contributed to a gradient higher hydrophilicity. The subsequent unidirectional water motion effectively isolates pathogenic aerosols typically generated by external individuals or ultrafast water penetration from the inverse face. Moreover, the membranes demonstrated an antibacterial efficacy (>99.99%) in a 5 min contact, inactivating the intercepted airborne pathogens efficiently. The test results proved that the proposed membranes were promising advanced air filters for respirator applications.

Single-Side Superhydrophobicity in Si3N4-Doped and SiO2-Treated Polypropylene Nonwoven Webs with Antibacterial Activity

Meltblown (MB) nonwovens as air filter materials have played an important role in protecting people from microbe infection in the COVID-19 pandemic. As the pandemic enters the third year in this current global event, it becomes more and more beneficial to develop more functional MB nonwovens with special surface selectivity as well as antibacterial activities. In this article, an antibacterial polypropylene MB nonwoven doped with nano silicon nitride (Si₃N₄), one of ceramic materials, was developed. With the introduction of Si₃N₄, both the average diameter of the fibers and the pore diameter and porosity of the nonwovens can be tailored. Moreover, the nonwovens having a single-side moisture transportation, which would be more comfortable in use for respirators or masks, was designed by imparting a hydrophobicity gradient through the single-side superhydrophobic finishing of reactive organic/inorganic silicon coprecipitation in situ. After a nano/micro structural SiO₂ precipitation on one side of the fabric surfaces, the contact angles were up to 161.7° from 141.0° originally. The nonwovens were evaluated on antibacterial activity, the result of which indicated that they had a high antibacterial activity when the dosage of Si₃N₄ was 0.6 wt%. The bacteriostatic rate against E. coli and S. aureus was up to over 96%. Due to the nontoxicity and excellent antibacterial activity of Si₃N₄, this MB nonwovens are promising as a high-efficiency air filter material, particularly during the pandemic.

A Trilayered Composite Fabric with Directional Water Transport and Resistance to Blood Penetration for Medical Protective Clothing

Functional textiles with enhanced moisture management can facilitate sweat transport away from the skin to improve personal comfort. However, porous materials exhibit low capability of preventing the intrusion of external liquids, becoming a bottleneck in the design of medical protective clothing. Herein, a trilayered composite fabric based on a gradient wettability structure is demonstrated for directional water transport and resistance to blood penetration. The proposed fabric shows distinct advantages, including a high water breakthrough pressure of 2.43 kPa from the external side, an outstanding positive water transport index (1522%), and an antiblood penetration resistance of 2.71 kPa. Moreover, the fabric shows improved comfort with a high moisture transmission (320 g m^-2 h^-1) and desired water evaporation rate (0.36 g h^-1). This work addressed the concern of directional water transport and resistance to blood penetration while providing a comfortable wearing microenvironment, leading to a promising research direction for multifunctional medical textiles.

Synchronous Engineering for Biomimetic Murray Porous Membranes Using Isocyanate

Highly permselective and durable membranes are desirable for massive separation applications. However, currently most membranes prepared using nonsolvent-induced phase separation (NIPS) suffer from low permeability and a high fouling tendency due to the great challenges in a rational design and also practical approach for membrane optimization. Inspired by the natural Murray network from vascular plants, we developed a hierarchical membrane via a straightforward yet robust strategy, using isocyanate as a multifunctional additive. Thanks to the integrated functions of a phase separation regulator, blowing agent, cross-linker, and functionalization anchor of isocyanate, our strategy is featured as a perfect combination of a phase separation and chemical reaction, and it enables synchronous engineering of the membrane hierarchy on porosity and components. The representative membrane exhibits superior water permeance (334 L/m²·h·bar), protein retention (>98%), and antifouling ability (flux recover ratio ∼ 98%). This work highlights a versatile path for pursuing a highly enhanced performance of NIPS-made membranes, from the fancy perspective of Murray bionics.

Underwater Unidirectional Cellular Fluidics

The unidirectional fluidics underwater promises the manipulation of gas/liquid for various significant applications. Inspired by the unique stomata on the surface of hornwort stems and leaves that enable the transport and storage of oxygen underwater, we propose a bionic cell with porous membranes fabricated by the projection microstereolithography based 3D printing technique. Different Laplace forces coming from different contact angles for the respectively superhydrophilic outside and hydrophobic inside promise unidirectional fluidic performance, which stop water flowing inside of the bionic cell while exhausting gas and liquid outside of it. In addition, geometric parameters of the bionic cell make a big difference in its unique unidirectional fluidic performance. Simultaneously, the underlying mechanisms of the unidirectional penetration of liquid in our 3D printed bionic cell are theoretically revealed. Moreover, we demonstrate potential applications of our bionic cell with underwater anaerobic chemical reactions to fully apply its outstanding unidirectional fluidics underwater. Our bionic cell opens a gate for potential applications in chemical and microfluidic engineering underwater, such as the storage of flammable materials, fast solid-liquid separations, and anaerobic chemical reactions.

Bilayer Nanoporous Polyethylene Membrane with Anisotropic Wettability for Rapid Water Transportation/Evaporation and Radiative Cooling

Both sweat drainage and evaporation play important roles in achieving personal moisture and thermal management during sweat-producing exercises. However, it remains a great challenge to simultaneously realize thermal management through radiative cooling for human body without perspiration. Herein, we report a bilayer nanoporous polyethylene membrane with anisotropic wettability, which possesses superior radiative cooling ability (∼2.6 °C lower than that of cotton) without perspiration. Meanwhile, it realizes efficient sweat drainage and good evaporation cooling property (∼1.0 °C lower than that of cotton) in perspiration to avoid sticky and hot sensation. In addition, it can also block water and fine particulate matter owing to the hydrophobic nanoporous structure. By virtue of the outstanding personal thermal and moisture management performance, it is expected that this study provides inspiration for designing new clothing and medical protective suits with more comfortable microclimates and reducing energy consumption for global sustainability.

Review on the Development and Application of Directional Water Transport Textile Materials

Moisture (sweat) management in textile products is crucial to regulate human thermo-physiological comfort. Traditional hydrophilic textiles, such as cotton, can absorb sweat, but they retain it, leading to undesired wet adhesion sensation and even excessive cooling. To address such issues, the development of functional textiles with directional water transport (DWT) has garnered great deal of interest. DWT textile materials can realize directional water transport and prevent water penetration in the reverse direction, which is a great application for sweat release in daily life. In this review article, the mechanism of directional water transport is analyzed. Then, three key methods to achieve DWT performance are reviewed, including the design of the fabric structure, surface modification and electrospinning. In addition, the applications of DWT textile materials in functional clothing, electronic textiles, and wound dressing are introduced. Finally, the challenges and future development trends of DWT textile materials in the textile field are discussed.

Effects of the Surface Structure on the Water Transport Behavior in PEMFC Carbon Fiber Papers

In this paper, three kinds of carbon fiber papers (CFPs), including pure CFP, poly(tetrafluoroethylene) (PTFE)-treated CFP (PTFE-CFP), and microporous layer (MPL)-coated CFP (MPL-CFP), were used to investigate the effects of the surface structure on the water transport behavior in CFPs. Compared to pure CFP, applying PTFE on the CFP increases the breakthrough pressure by 0.2 times, while it decreases the water flow rate at initial penetration by 0.06 times, owing to the strong hydrophobicity of PTFE-CFP. The pore diameter of MPL-CFP reduces sharply after coating the MPL, which leads to increasing breakthrough pressure by 0.6 times. The Young-Laplace equation is applied to study the relationship between the structure (wettability and pore-size distribution) of CFPs and the water transport behavior (breakthrough pressure), and the results show that in addition to wettability and pore size, the pore-size gradient also plays a crucial role in water transport.

A Moisture-Wicking Passive Radiative Cooling Hierarchical Metafabric

Developing functional textiles with a cooling effect is important for personal comfort in human life and activities. Although existing passive cooling fabrics exhibit promising cooling effects, they do not meet the thermal comfort requirements under many practical conditions. Here, we report a nanofiber membrane-based moisture-wicking passive cooling hierarchical metafabric that couples selective optical cooling and wick-evaporation cooling to achieve efficient temperature and moisture management. The hierarchical metafabric showed high sunlight reflectivity (99.16% in the 0.3-0.76 μm wavelength range and 88.60% in the 0.76-2.5 μm wavelength range), selective infrared emissivity (78.13% in the 8-13 μm wavelength range), and good moisture permeability owing to the optical properties of the material and hierarchical morphology design. Cooling performance experiments revealed that covering simulated skin with the hierarchical metafabric prevented overheating by 16.6 °C compared with traditional textiles, including a contribution from management of the humidity (∼8.2 °C). In addition to the personal thermal management ability, the hierarchical metafabric also showed good wearability.

The High Flux of Superhydrophilic-Superhydrophobic Janus Membrane of cPVA-PVDF/PMMA/GO by Layer-By-Layer Electrospinning for High Efficiency Oil-Water Separation

A simple and novel strategy of superhydrophilic-superhydrophobic Janus membrane was provided here to deal with the increasingly serious oil-water separation problem, which has a very bad impact on environmental pollution and resource recycling. The Janus membrane of cPVA-PVDF/PMMA/GO with opposite hydrophilic and hydrophobic properties was prepared by layer-by-layer electrospinning. The structure of the Janus membrane is as follows: firstly, the mixed solution of polyvinylidene fluoride (PVDF), polymethylmethacrylate (PMMA) and graphene oxide (GO) was electrospun to form a hydrophobic layer, then polyvinyl alcohol (PVA) nanofiber was coated onto the hydrophobic membrane by layer-by-layer electrospinning to form a composite membrane, and finally, the composite membrane was crosslinked to obtain a Janus membrane. The addition of GO can significantly improve the hydrophobicity, mechanical strength and stability of the Janus membrane. In addition, the prepared Janus membrane still maintained good oil-water separation performance and its separation efficiency almost did not decrease after many oil-water separation experiments. The flux in the process of oil-water separation can reach 1909.9 L m⁻² h⁻¹, and the separation efficiency can reach 99.9%. This not only proves the separation effect of the nanocomposite membrane, but also shows its high stability and recyclability. The asymmetric Janus membrane shows good oil-water selectivity, which gives Janus membrane broad application prospects in many fields.

Highly Transparent Nanofibrous Membranes Used as Transparent Masks for Efficient PM0.3 Removal

Currently, the quest for highly transparent and flexible fibrous membranes with robust mechanical characteristics, high breathability, and good filtration performance is rapidly rising because of their potential use in the fields of electronics, energy, environment, medical, and health. However, it is still an extremely challenging task to realize transparent fibrous membranes due to serious surface light reflection and internal light scattering. Here, we report the design and development of a simple and effective topological structure to create porous, breathable, and high visible light transmitting fibrous membranes (HLTFMs). The resultant HLTFMs exhibit good optical performance (up to 90% transmittance) and high porosities (>80%). The formation of such useful structure with high light transmittance has been revealed by electric field simulation, and the mechanism of fibrous membrane structure to achieve high light transmittance has been proposed. Moreover, transparent masks have been prepared to evaluate the filtration performance and analyze their feasibility to meet requirement of facial recognition systems. The prepared masks display high transparency (>80%), low pressure drop (<100 Pa) and high filtration efficiency (>90%). Furthermore, the person wearing this mask can be successfully identified by facial recognition systems. Therefore, this work provides an idea for the development of transparent, breathable, and high-performance fibrous membranes.

Biomimetic Aligned Micro-/Nanofibrous Composite Membranes with Ultrafast Water Transport and Evaporation for Efficient Indoor Humidification

Humidifying membranes with ultrafast water transport and evaporation play a vital role in indoor humidification that improves personal comfort and industrial productivity in daily life. However, commercial nonwoven (NW) humidifying membranes show mediocre humidification capability owing to limited wicking capacity, low water absorption, and relatively less water evaporation. Herein, we report a biomimetic micro-/nanofibrous composite membrane with a highly aligned fibrous structure using a humidity-induced electrospinning technique for high-efficiency indoor humidification. Surface wettability and roughness are also tailored to achieve a high degree of superhydrophilicity by embedding hydrophilic silicon dioxide nanoparticles (SiO₂ NPs) into the fiber matrix. The synergistic effect of the highly aligned fibrous structure and surface wettability endows composite membranes with ultrafast water transport and evaporation. Strikingly, the composite membrane exhibits an outstanding wicking height of 19.5 cm, a superior water absorption of 497.7%, a fast evaporation rate of 0.34 mL h^-1, and a relatively low air pressure drop of 14.4 Pa, thereby achieving a remarkable humidification capacity of 514 mL h^-1 (57% higher than the commercial NW humidifying membrane). The successful synthesis of this biomimetic micro-/nanofibrous composite membrane provides new insights into the development of micro-/nanofibrous humidifying membranes for personal health and comfort as well as industrial production.

Microscopic Observation of Preferential Capillary Pumping in Hollow Nanowire Bundles

Numerous studies have focused on designing micro/nanostructured surfaces to improve wicking capability for rapid liquid transport in many industrial applications. Although hierarchical surfaces have been demonstrated to enhance wicking capability, the underlying mechanism of liquid transport remains elusive. Here, we report the preferential capillary pumping on hollow hierarchical surfaces with internal nanostructures, which are different from the conventional solid hierarchical surfaces with external nanostructures. Specifically, capillary pumping preferentially occurs in the nanowire bundles instead of the interconnected V-groove on hollow hierarchical surfaces, observed by confocal laser scanning fluorescence microscopy. Theoretical analysis shows that capillary pumping capability is mainly dependent on the nanowire diameter and results in 15.5 times higher capillary climbing velocity in the nanowire bundles than that in the microscale V-groove. Driven by the Laplace pressure difference between nanowire bundles and V-grooves, the preferential capillary pumping is increased with the reduction of the nanowire diameter. Capillary pumping of the nanowire bundles provides a preferential path for rapid liquid flow, leading to 2 times higher wicking capability of the hollow hierarchical surface comparing with the conventional hierarchical surface. The unique mechanism of preferential capillary pumping revealed in this work paves the way for wicking enhancement and provides an insight into the design of wicking surfaces for high-performance capillary evaporation in a broad range of applications.

Nanoarchitectonics for Electrospun Membranes with Asymmetric Wettability

Membranes with asymmetric wettability have attracted significant interest by virtue of their unique transport characteristics and functionalities arising from different wetting behaviors of each membrane surface. The cross-sectional wettability distinction enables a membrane to realize directional liquid transport or multifunction integration, resulting in rapid advance in applications, such as moisture management, fog collection, oil-water separation, and membrane distillation. Compared with traditional homogeneous membranes, these membranes possess enhanced transport performance and higher separation efficiency owing to the synergistic or individual effects of asymmetric wettability. This Review covers the recent progress in fabrication, transport mechanisms, and applications of electrospun membranes with asymmetric wettability and provides a perspective on future development in this important area.

Biospired Janus Silk E-Textiles with Wet-Thermal Comfort for Highly Efficient Biofluid Monitoring

Functionalized textiles capable of biofluid administration are favorable for enhancing the wet-thermal comfort of the wearer and healthcare performance. Herein, inspired by the Janus wettability of lotus leaf, we propose a skin-comfortable Janus electronic textile (e-textile) based on natural silk materials for managing and analysis of biofluid. Silk materials are chosen and modified as both a textile substrate and a sensing electrode due to its natural biocompatibility. The unidirectional biofluid behavior of such Janus silk substrate facilitates a comfortable skin microenvironment, including weakening the undesired wet adhesion (∼0 mN cm^-2) and avoiding excessive heat or cold on the epidermis. We noninvasively analyze multiple targets of human sweat with less required liquid volume (∼5 μL) and a faster (2-3 min) response time based on the silk-based yarn electrode woven into the hydrophilic side of Janus silk. This work bridges the gap between physiological comfort and sensing technology using biomass-derived elements, presenting a new type of smart textiles for wet-thermal management and health monitoring.

Integrated cooling (i-Cool) textile of heat conduction and sweat transportation for personal perspiration management

Perspiration evaporation plays an indispensable role in human body heat dissipation. However, conventional textiles tend to focus on sweat removal and pay little attention to the basic thermoregulation function of sweat, showing limited evaporation ability and cooling efficiency in moderate/profuse perspiration scenarios. Here, we propose an integrated cooling (i-Cool) textile with unique functional structure design for personal perspiration management. By integrating heat conductive pathways and water transport channels decently, i-Cool exhibits enhanced evaporation ability and high sweat evaporative cooling efficiency, not merely liquid sweat wicking function. In the steady-state evaporation test, compared to cotton, up to over 100% reduction in water mass gain ratio, and 3 times higher skin power density increment for every unit of sweat evaporation are demonstrated. Besides, i-Cool shows about 3 °C cooling effect with greatly reduced sweat consumption than cotton in the artificial sweating skin test. The practical application feasibility of i-Cool design principles is well validated based on commercial fabrics. Owing to its exceptional personal perspiration management performance, we expect the i-Cool concept can provide promising design guidelines for next-generation perspiration management textiles.

Lizard-Skin-Inspired Nanofibrous Capillary Network Combined with a Slippery Surface for Efficient Fog Collection

Freshwater shortage is a critical global issue that needs to be resolved urgently. Efficient water collection from fog provides a promising and sustainable solution to produce clean drinking water, especially in the desert and arid regions. Nature has long served as our best source of inspiration for designing new structures and developing new materials. Herein, we report a strategy to design a novel Janus fog collector with a hydrophilic lizard-skin-like nanofibrous network upper surface and hydrophobic slippery lower surface using a simple and feasible method of coating and electrospinning. We analyze the forming law of the lizard-skin-like nanofibrous network structure on different substrates using electric field simulation. The resulting copper mesh-based Janus fog collector exhibits superior water-collecting efficiency (907 mg cm^-2 h^-1) and long-term durability, achieving directional transport of tiny droplets and high-efficiency water collection. However, there are few reports on the combination of the lizard-skin-like nanofibrous capillary network and slippery surface for efficient fog collection. Therefore, we believe that this work will open a new avenue to collect water efficiently and also provide clues to research on the lizard-skin-like nanofibrous network structure.

Moisture-Wicking and Solar-Heated Coaxial Fibers with a Bark-like Appearance for Fabric Comfort Management

Maintaining the human body's comfort is a predominant requirement of functional textiles, but there are still considerable drawbacks to design an intelligent textile with proper moisture absorption and evaporation properties. Herein, we develop moisture-wicking and solar-heated coaxial fibers with a bark-like appearance for fabric comfort management. The cortex layer of coaxial fibers can absorb moisture via the synergistic effect of the hierarchical roughness and the hydrophilic polymeric matrix. The core layer containing zirconium carbide nanoparticles can assimilate energy from the body and sunlight, which raises the surface temperature of the material and accelerates moisture evaporation. The resulting coaxial fiber-based membrane exhibits an excellent droplet diffusion radius of 2.73 cm, an excellent wicking height of 6.97 cm, and a high surface temperature of 61.7 °C which is radiated by simulated sunlight. Moreover, the designed fabric also exhibits a significant UV protection factor of 2000. Overall, the successful synthesis of such fascinating fibrous membranes enables the rapid removal of sweat from the human body textile, providing a suitable and comfortable microenvironment for the human body.

Intelligent Polymers, Fibers and Applications

Intelligent materials, also known as smart materials, are capable of reacting to various external stimuli or environmental changes by rearranging their structure at a molecular level and adapting functionality accordingly. The initial concept of the intelligence of a material originated from the natural biological system, following the sensing–reacting–learning mechanism. The dynamic and adaptive nature, along with the immediate responsiveness, of the polymer- and fiber-based smart materials have increased their global demand in both academia and industry. In this manuscript, the most recent progress in smart materials with various features is reviewed with a focus on their applications in diverse fields. Moreover, their performance and working mechanisms, based on different physical, chemical and biological stimuli, such as temperature, electric and magnetic field, deformation, pH and enzymes, are summarized. Finally, the study is concluded by highlighting the existing challenges and future opportunities in the field of intelligent materials.

Bioinspired Hierarchical Nanofabric Electrode for Silicon Hydrovoltaic Device with Record Power Output

Direct electricity generation from water flow/evaporation, coined hydrovoltaic effect, has recently attracted intense interest as a facile approach to harvest green energy from ubiquitous capillary water flow or evaporation. However, the current hydrovoltaic device is inferior in output power efficiency compared to other renewable energy devices. Slow water evaporation rate and inefficient charge collection at device electrodes are two fundamental drawbacks limiting energy output efficiency. Here, we report a bioinspired hierarchical porous fabric electrode that enables high water evaporation rate, efficient charge collection, and rapid charge transport in nanostructured silicon-based hydrovoltaic devices. Such an electrode can efficiently collect charges generated in nanostructured silicon as well as induce a prompt water evaporation rate. At room temperature, the device can generate an open-circuit voltage (V_oc) of 550 mV and a short-current density (J_sc) of 22 μA·cm^-2. It can output a power density over 10 μW·cm^-2, which is 3 orders of magnitude larger than all those reported for analogous hydrovoltaic devices. Our results could supply an effective strategy for the development of high-performance hydrovoltaic devices through optimizing electrode structures.

Bioinspired Hybrid Micro/Nanostructure Composited Membrane with Intensified Mass Transfer and Antifouling for High Saline Water Membrane Distillation

Membrane distillation (MD) holds great promise for high-saline solution treatment, but it is typically impeded by the trade-off between the high mass transfer and antifouling properties of the membrane. Herein, a new MD utilized membrane with bioinspired micro/nanostructure (lotus leaf and fish gill) was constructed on commercial PP membrane, which can simultaneously enhance the permeation flux and antifouling in the hypersaline MD operation. On the basis of the classic nucleation theory and hydrodynamics simulation, the nanoscale structure can intensify the interfacial nanoscale turbulent flow and hinder the crystal deposition, which works like the fish gill. In addition, the optimized nanoscale feature size renders the membrane with the heterogeneous nucleation barrier very similar to the homogeneous system, which works like the lotus leaf and hinders the induced nucleation effectively. The microscale structure as the supporting platform of nanostructure can additionally enlarge the effective evaporative surface with superior hydrophobicity and then promote the permeation transfer through the membrane. The hybrid micro/nanostructures render the fabricated membrane with excellent high-permeation flux and significantly prolonged fouling induction time, which sheds light on a new approach for the development of ideal MD utilized membrane.

Rational 3D Coiled Morphology for Efficient Solar-Driven Desalination

Aiming at the global water scarcity, solar-driven desalination based on photothermal materials is identified as a promising strategy for freshwater production because of sustainability, spontaneity, and flexibility. Water transfer in photothermal materials, especially ones with 3D morphologies, can adjust the evaporation efficiency as a critical factor. In this work, a rationally designed roll morphology has been introduced into photothermal to advance the water transfer evaporation via controllable capillary action. The vertical intervals of the roll, similar to slit pore, can pump the water up to the entire materials to not only keep a stable vapor generation rate but reject salt precipitation. Additionally, the roll morphology also improves the light-harvesting via both the high roughness surface and confinement absorption inside the intervals. With excellent water transfer and energy management, photothermal roll showed an evaporation rate up to 1.93 ± 0.05 kg m^-2 h^-1, which was over 44% higher than the flat sample in the same constituents. Under actual conditions, the freshwater generation rate was achieved up to 1.09 kg m^-2 h^-1 on average of the whole daylight hours. The work provides novel insights into the design of efficient morphology in photothermal materials and advances their practical applications in sustainable water generation.

Simply Adjusting the Unidirectional Liquid Transport of Scalable Janus Membranes toward Moisture-Wicking Fabric, Rapid Demulsification, and Fast Oil/Water Separation

Inspired by nature, Janus membranes with unidirectional liquid transport (ULT) were developed to be used in the fields of fog collection, moisture-wicking fabrics, demulsification, etc. However, the obtained Janus membranes are often unifunctional, and it is still a great challenge to adjust the ULT of Janus membranes for multifunctional applications. Herein, a scalable, low-cost, and machine-washable Janus membrane was developed by combining the cyclic self-assembly of phytic acid and Fe^III and a one-side spraying coating of poly(dimethylsiloxane) (PDMS), featuring adjustable ULT upon challenge for multifunctional applications. By controlling the amount of PDMS, the Janus membranes exhibit two different performances, ULT and switchable permeation. The prepared Janus membranes achieved an excellent moisture-wicking fabric (1.6× the water evaporation rate of cotton), fast water collection under oil, rapid demulsification, and the efficient separation of an oil/water mixture. The separation efficiency of a light or heavy oil from water was higher than 99.9% even after 10 separation cycles, and the flux of the separation was up to 2.55 × 10⁴ or 2.38 × 10⁴ L m^-2 h^-1, respectively. This study could provide an idea for the development of more Janus membranes with adjustable performances to realize multifunctional applications.

Hierarchy in materials for maximized efficiency

This perspective article gives the future research direction on the application of the generalized Murray's law for the design of porous hierarchy in materials and the establishment of a general materials design theory 'law of hierarchy' taking four types of hierarchy into account.

Smart Ti3C2Tx MXene Fabric with Fast Humidity Response and Joule Heating for Healthcare and Medical Therapy Applications

An increasing utilization of flexible healthcare electronics and biomedicine-related therapeutic materials urges the development of multifunctional wearable/flexible smart fabrics for personal therapy and health management. However, it is currently a challenge to fabricate multifunctional and on-body healthcare electronic devices with reliable mechanical flexibility, excellent breathability, and self-controllable joule heating effects. Here, we fabricate a multifunctional MXene-based smart fabric by depositing 2D Ti₃C₂T_x nanosheets onto cellulose fiber nonwoven fabric via special MXene-cellulose fiber interactions. Such multifunctional fabrics exhibit sensitive and reversible humidity response upon H₂O-induced swelling/contraction of channels between the MXene interlayers, enabling wearable respiration monitoring application. Besides, it can also serve as a low-voltage thermotherapy platform due to its fast and stable electro-thermal response. Interestingly, water molecular extraction induces electrical response upon heating, i.e., functioning as a temperature alarm, which allows for real-time temperature monitoring for thermotherapy platform without low-temperature burn risk. Furthermore, metal-like conductivity of MXene renders the fabric an excellent Joule heating effect, which can moderately kill bacteria surrounding the wound in bacteria-infected wound healing therapy. This work introduces a multifunctional smart flexible fabric suitable for next-generation wearable electronic devices for mobile healthcare and personal medical therapy.

Thermoconductive, Moisture-Permeable, and Superhydrophobic Nanofibrous Membranes with Interpenetrated Boron Nitride Network for Personal Cooling Fabrics

Space cooling occupies a large portion of total building energy consumption, aggravating the energy crisis and restricting human sustainable development, thus an efficient and energy-saving personal cooling technology is in high demand. Recently, thermally conductive fillers, such as boron nitride (BN), are usually enriched to fibrous materials to construct thermal management textiles. However, these fabrication processes are complex and time-consuming, and the resultant materials fail to transmit moisture and resist liquid water. Herein, we develop a facile and scalable methodology to construct highly thermoconductive breathable superhydrophobic nanofibrous membranes to enhance the thermal management of textiles for personal cooling. The strategy causes boron nitride (BN) to be linked with each other along nanofibers, and thus the membranes contain well interpenetrated BN network and remain porous structure simultaneously, improving their thermal conductivity without sacrificing the moisture permeability. In addition, the membranes possess good resistance to water penetration and intriguing superhydrophobicity due to the synergistic effect of the hydrophobic polymeric matrix and improved roughness. As a consequence, the resultant membranes demonstrate outstanding hybrid active-passive cooling performance with ultrahigh in-plane thermal conductivity of 17.9 W m^-1 K^-1, cross-plane thermal conductivity of 0.29 W m^-1 K^-1, and high water vapor transmission (WVT) rate of 11.6 kg m^-2 day^-1, as well as excellent water repellency with water contact angle of 153° and high hydrostatic pressure of 32 kPa, indicating promising utility for the next generation of cooling fabrics.

Integrated Smart Janus Textile Bands for Self-Pumping Sweat Sampling and Analysis

Wearable sweat sensors have spearheaded the thrust toward personalized health monitoring with continuous, real-time, and molecular-level insight in a noninvasive manner. However, effective sweat sampling still remains a huge challenge. Here, we introduce an intelligent Janus textile band that bridges the gap between self-pumping sweat collection, comfortable epidemic microclimate, and sensitive electrochemical biosensing via an integrated wearable platform. The dominant sweat sampling configuration is a textile with Janus wettability, which is fabricated by electrospinning a hydrophobic polyurethane (PU) nanofiber array onto superhydrophilic gauze. Based on a contact-pumping model, the Janus textile can unidirectionally and thoroughly transport sweat from skin (hydrophobic side) to embedded electrode surface (hydrophilic side) with epidemic comfort. On-body experimentation reveals that the sensitive detection of multiple biomarkers including glucose, lactate, K⁺, and Na⁺ is achieved in the pumped sweat. Such smart Janus textile bands can effectively drain epidermal sweat to targeted assay sites via interface modifications, representing a reinforced and controlled biofluids analysis pathway with physiological comfort.

Highly Flexible Monolayered Porous Membrane with Superhydrophilicity-Hydrophilicity for Unidirectional Liquid Penetration

The ability to allow microliquid to penetrate in one direction but block in the opposite direction plays an irreplaceable role in intelligent liquid management. Despite much progress toward facilitating directional transport by multilayer porous membranes with opposite wettability, it remains difficult to achieve a highly multifunctional flexible membrane for highly efficient unidirectional liquid transport in different situations. Herein, a superhydrophilic-hydrophilic self-supported monolayered porous poly(ether sulfone) (PES) membrane with special nano- and micropores at opposite surfaces is demonstrated, which can be used for unidirectional liquid transport. The results reveal that the competition of liquid spreading and permeation is critical to achieve directional liquid transport. The porous PES membrane, transformed with 70 vol % of ethanol in water (E/W-PES-70%), exhibits continuous unidirectional liquid penetration and antigravity unidirectional ascendant in a large range of pH values and can be used as "liquid diode" for moisture wicking. Moreover, the PES membrane can be prepared in a large area with excellent flexibility at room and liquid nitrogen temperature, indicating great promise in harsh environments. This work will provide an avenue for designing porous materials and smart dehumidification materials, which have promising applications in biomedical materials, advanced functional textiles, engineered desiccant materials, etc.

Multifunctional, Waterproof, and Breathable Nanofibrous Textiles Based on Fluorine-Free, All-Water-Based Coatings

Developing environmentally benign, multifunctional waterproof and breathable membranes (WBMs) is of great importance but still faces enormous challenges. Here, an environmentally benign fluorine-free, ultraviolet (UV) blocking, and antibacterial WBM with a high level of waterproofness and breathability is developed on a large scale by combining electrospinning and step-by-step surface coating technology. Fluorine-free water-based alkylacrylates with long hydrocarbon chains were coated onto polyamide 6 fibrous membranes to construct robust hydrophobic surfaces. The subsequent titanium dioxide nanoparticle emulsion coating prominently decreased the maximum pore size, leading to higher water resistance, endowing the membranes with efficient UV-resistant and antibacterial properties. The resulting fibrous membranes possessed excellent waterproofness of 106.2 kPa, exceptional breathability of 10.3 kg m^-2 d^-1, a significant UV protection factor of 430.5, together with a definite bactericidal efficiency of 99.9%. We expect that this methodology for construction of environmentally benign and multifunctional WBMs will shed light on the material design, and the prepared membranes could implement their promising applications in covering materials, outdoor equipment, protective clothing, and high-altitude garments.

Effect of Weaving Structures on the Water Wicking-Evaporating Behavior of Woven Fabrics

Water transfer through porous textiles consists of two sequential processes: synchronous wicking–evaporating and evaporating alone. In this work we set out to identify the main structural parameters affecting the water transfer process of cotton fabrics. Eight woven fabrics with different floats were produced. The fabrics were evaluated on a specially designed instrument capable of measuring the water loss through a vertical wicking process. Each test took 120 min, and two phases were defined: Phase I for the first 10 min and Phase II for the last 110 min according to wicking behavior transition. Principal components and multivariate statistical methods were utilized to analyze the data collected. The results showed that Phase I dominated the whole wicking–evaporating process, and the moisture transfer speed in this phase varied with fabric structure, whereas the moisture transfer speeds in Phase II were similar and constant regardless of fabric structure. In addition, fabric with more floats has high water transfer speed in Phase I due to its loosened structure with more macropores.

Fluorine-Free Waterborne Coating for Environmentally Friendly, Robustly Water-Resistant, and Highly Breathable Fibrous Textiles

Waterproof and breathable membranes (WBMs) with simultaneous environmental friendliness and high performance are highly desirable in a broad range of applications; however, creating such materials still remains a tough challenge. Herein, we present a facile and scalable strategy to fabricate fluorine-free, efficient, and biodegradable WBMs via step-by-step dip-coating and heat curing technology. The hyperbranched polymer (ECO) coating containing long hydrocarbon chains provided an electrospun cellulose acetate (CA) fibrous matrix with high hydrophobicity; meanwhile, the blocked isocyanate cross-linker (BIC) coating ensured the strong attachment of hydrocarbon segments on CA surfaces. The resulting membranes (TCA) exhibited integrated properties with waterproofness of 102.9 kPa, breathability of 12.3 kg m^-2 d^-1, and tensile strength of 16.0 MPa, which are much superior to that of previously reported fluorine-free fibrous materials. Furthermore, TCA membranes can sustain hydrophobicity after exposure to various harsh environments. More importantly, the present strategy proved to be universally applicable and effective to several other hydrophilic fibrous substrates. This work not only highlights the material design and preparation but also provides environmentally friendly and high-performance WBMs with great potential application prospects for a variety of fields.

Tunable Water Delivery in Carbon-Coated Fabrics for High-Efficiency Solar Vapor Generation

Solar vapor generation by localized heating and evaporation has potential to be a viable and "green" way to produce fresh water. This work reports a carbon black-coated cotton fabric with a tunable water delivery property for high-efficiency solar vapor generation under 1 sun. The fabric is prepared by an electrospray of poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) on one-side of the fabric followed by dip-coating of the fabric with carbon black as a photothermal absorber. Depending on the duration of electrospray, the roughness gradient generated by the PVDF-HFP layer in the fabric leads to guided and continuous one-way water transport from the electrosprayed hydrophobic side to the hydrophilic side with a tunable delivery rate. The tunable water delivery capability of the fabric regulates the amount of water supplied to the vicinity of the photothermal absorber. Additionally, the fabric shows excellent broadband absorption and low thermal conductivity. In comparison with the carbon black-coated fabric without a roughness gradient, the regulation of water improves the solar vapor conversion efficiency, owing to reduced heat loss and better heat allocation. Under optimal conditions, a solar vapor conversion efficiency of 88.9% and a stable water evaporation rate of 1.33 kg (m²·h)^-1 under 1 sun are achieved.

All-fiber tribo-ferroelectric synergistic electronics with high thermal-moisture stability and comfortability

Developing fabric-based electronics with good wearability is undoubtedly an urgent demand for wearable technologies. Although the state-of-the-art fabric-based wearable devices have shown unique advantages in the field of e-textiles, further efforts should be made before achieving "electronic clothing" due to the hard challenge of optimally unifying both promising electrical performance and comfortability in single device. Here, we report an all-fiber tribo-ferroelectric synergistic e-textile with outstanding thermal-moisture comfortability. Owing to a tribo-ferroelectric synergistic effect introduced by ferroelectric polymer nanofibers, the maximum peak power density of the e-textile reaches 5.2 W m^-2 under low frequency motion, which is 7 times that of the state-of-the-art breathable triboelectric textiles. Electronic nanofiber materials form hierarchical networks in the e-textile hence lead to moisture wicking, which contributes to outstanding thermal-moisture comfortability of the e-textile. The all-fiber electronics is reliable in complicated real-life situation. Therefore, it is an idea prototypical example for electronic clothing.

Infrared-Radiation-Enhanced Nanofiber Membrane for Sky Radiative Cooling of the Human Body

Extreme heat events are mainly responsible for weather-related human mortality due to climate change. However, there is a lack of outdoor thermal management for protecting people from extreme heat events. We present a novel infrared-radiation-enhanced nanofiber membrane (NFM) that has good infrared resonance absorption and selectively radiates thermal radiation of the human body through the atmosphere and into the cold outer space. The NFM comprises polyamide 6 (PA6) nanofibers and randomly distributed SiO₂ submicron spheres and has sufficient air permeability and thermal-moisture comfortability because of its interconnect nanopores and micropores. We measure the sky radiative cooling performance under a clear sky, and PA6/SiO₂ NFM produces temperatures that are about 0.4-1.7 °C lower than those of commercial textiles when covering dry and wet hands and temperatures 1.0-2.5 °C lower than the ambient temperature when thermal conduction and convection are isolated in a closed device. Our processed PA6/SiO₂ NFM combines sky radiative cooling with thermal management of the human body very well, which will promote the development of radiative cooling textiles.