Stretchable and Freeze-Tolerant Organohydrogel Thermocells with Enhanced Thermoelectric Performance Continually Working at Subzero Temperatures

Aqueous thermocells that are eco-friendly and capable of converting low-grade heat into electricity continuously are promising candidates to power flexible and wearable devices in various application scenarios. However, challenges remain in their limited working temperatures, mechanical fragility, and poor thermoelectric performance, mainly due to the reduced entropy of both polymer chains and thermogalvanic ions at low temperatures. In this work, the challenges are addressed by introducing a synergistic chaotropic effect to destruct strong hydrogen bonds, increase polymers’ entropic elasticity, and enlarge the entropy difference of thermogalvanic ions. An organohydrogel thermocell is designed with a chaotropic comonomer and a chaotropic cosolvent. The maximum normalized power density of the thermocell achieves 0.1 mW m⁻² K⁻², which is in the same order of magnitude as the highest record in current quasi-solid thermocells. Even at −30 °C, the thermocell maintains the elongation at a break of more than 100% and a relatively high power density of 0.012 mW m⁻² K⁻². Furthermore, the thermocell shows the potential to light up a light-emitting diode and stably works when compressed, bent, and stretched in a wide temperature range. This work provides insights on developing reliable power sources to drive flexible electronics continually in extremely cold environments.     

Photocurable 3D Printing of High Toughness and Self-Healing Hydrogels for Customized Wearable Flexible Sensors

Currently, most customized hydrogels can only be processed via extrusion-based 3D printing techniques, which is limited by printing efficiency and resolution. Here, a simple strategy for the rapid fabrication of customized hydrogels using a photocurable 3D printing technique is presented. This technique has been rarely used because the presence of water increases the molecular distance between the polymer chains and reduces the monomer polymerization rate, resulting in the failure of rapid solid-liquid separation during printing. Although adding cross-linkers to printing inks can effectively accelerate 3D cross-linked network formation, chemical cross-linking may result in reduced toughness and self-healing ability of the hydrogel. Therefore, an interpenetrated-network hydrogel based on non-covalent interactions is designed to form physical cross-links, affording fast solid-liquid separation. Poly(acrylic acid (AA)-N-vinyl-2-pyrrolidone (NVP)) and carboxymethyl cellulose (CMC) are cross-linked via Zn²⁺-ligand coordination and hydrogen bonding; the resulting mixed AA-NVP/CMC solution is used as the printing ink. The printed poly(AA-NVP/CMC) hydrogel exhibited high tensile toughness (3.38 MJ m⁻³) and superior self-healing ability (healed stress: 81%; healed strain: 91%). Some objects like manipulator are successfully customized by photocurable 3D printing using hydrogels with high toughness and complex structures. This high-performance hydrogel has great potential for application in flexible wearable sensors.     

Light‐Induced Swelling‐Responsive Conductive,Adhesive, and Stretchable Wireless Film Hydrogel as Electronic Artificial Skin

Light‐induced wireless soft electronic skin hydrogels with excellent mechanical and electronic properties are important for several applications, such as soft robotics and intelligent wearable devices. Precise control of reversible stretchability and capacitive properties depending on intermolecular interaction and surface characteristics remains a challenge. Here, a thin‐film hydrogel is designed based on titanium oxide (TiO₂) polydopamine–perfluorosilica carbon dot‐conjugated chitosan–polyvinyl alcohol‐loaded tannic acid with controllable hydrophobic–hydrophilic transition in the presence of UV–vis light irradiation. The shifting of surface wettability from hydrophobic to hydrophilic by irradiation affects thin‐film water permeability and swelling ratio. This allows the penetration of water into the matrix to change its mechanical strength, electronic properties, and adhesive behavior. Specifically, the hydrogel displays mechanical strain as high as 278% in response to light stimuli and demonstrates the ability to regain its initial state determining the elasticity of the fabricated material. Moreover, the thin‐film hydrogel shows an increase in conductivity to 1.096 × 10^?3 and 1.026 × 10^?3 S cm^?1 when irradiated with UV and visible light, respectively. The hydrogel exhibits capacitive reversibility that follows finger motion which can be identified directly or remotely using wireless connection, indicative of its possible applications as an artificial electronic skin.     

Metal-Organic Framework Reinforced Highly Stretchable and Durable Conductive Hydrogel-Based Triboelectric Nanogenerator for Biomotion Sensing and Wearable Human-Machine Interfaces

Flexible triboelectric nanogenerators (TENGs) with multifunctional sensing capabilities offer an elegant solution to address the growing energy supply challenges for wearable smart electronics. Herein, a highly stretchable and durable electrode for wearable TENG is developed using ZIF-8 as a reinforcing nanofiller in a hydrogel with LiCl electrolyte. ZIF-8 nanocrystals improve the hydrogel's mechanical properties by forming hydrogen bonds with copolymer chains, resulting in 2.7 times greater stretchability than pure hydrogel. The hydrogel electrode is encapsulated by microstructured silicone layers that act as triboelectric materials and prevent water loss from the hydrogel. Optimized ZIF-8-based hydrogel electrodes enhance the output performance of TENG through the dynamic balance of electric double layers (EDLs) during contact electrification. Thus, the as-fabricated TENG delivers an excellent power density of 3.47 Wm^–2, which is 3.2 times higher than pure hydrogel-based TENG. The developed TENG can scavenge biomechanical energy even at subzero temperatures to power small electronics and serve as excellent self-powered pressure sensors for human-machine interfaces (HMIs). The nanocomposite hydrogel-based TENG can also function as a wearable biomotion sensor, detecting body movements with high sensitivity. This study demonstrates the significant potential of utilizing ZIF-8 reinforced hydrogel as an electrode for wearable TENGs in energy harvesting and sensor technology.     

Piezoionic SnSe Nanosheets-Double Network Hydrogel for Self-Powered Strain Sensing and Energy Harvesting

Flexible strain sensors have enormous potential in wearable devices, robots, and health monitoring equipment. However, the poor stretchability of strain sensors based on semiconductors and the low sensitivity of resistance change-based hydrogel strain sensors hinders the comprehensive application. Herein, a flexible piezoionic SnSe-hydrogel composite with an optimized structure and improved performance is designed. The piezoionic output rises nonlinearly as the applied force increases, with the piezoionic coefficient up to 1780 nV Pa⁻¹ and −7.21 nA Pa⁻¹. The composite can realize the continuous positioning in 1D space based on the piezoionic effect. It also demonstrates self-powered characteristics, an ultrafast response speed of 6–8 ms, and a high gauge factor of 95.89. The sensor is exemplified to monitor fist clenching and finger bending, which has the potential to discriminate different joint movements. Meanwhile, the device can light up a light–emitting diode under pressure and bending. The as-prepared piezoionic SnSe-hydrogel device, having both high stretchability and sensitivity, may shed light on developing high-performance flexible strain sensors and generators.     

A Flexible and Safe Planar Zinc-Ion Micro-Battery with Ultrahigh Energy Density Enabled by Interfacial Engineering for Wearable Sensing Systems

Aqueous zinc-ion micro-batteries (ZIMBs) have attracted considerable attention owing to their reliable safety, low cost, and great potential for wearable devices. However, current ZIMBs still suffer from various critical issues, including short cycle life, poor mechanical stability, and inadequate energy density. Herein, the fabrication of flexible planar ZIMBs with ultrahigh energy density by interfacial engineering in the screen-printing process based on high-performance MnO₂-based cathode materials is reported. The Ce-doped MnO₂ (Ce-MnO₂) exhibits significantly enhanced capacity (389.3 mAh g⁻¹), considerable rate capability and admirable cycling stability than that of the pure MnO₂. Importantly, the fabrication of micro-electrodes with ultrahigh mass loading of Ce-MnO₂ (24.12 mg cm⁻²) and good mechanical stability is achieved through optimizing the interfacial bonding between different printed layers. The fabricated planar ZIMBs achieve a record high capacity (7.21 mAh cm⁻² or 497.31 mAh cm⁻³) and energy density (8.43 mWh cm⁻² or 573.45 mWh cm⁻³), as well as excellent flexibility. Besides, a wearable self-powered sensing system for environmental monitoring is further demonstrated by integrating the planar ZIMBs with flexible solar cells and a multifunctional sensor array. This work sheds light on the development of high-performance planar ZIMBs for future self-powered and eco-friendly smart wearable electronics.     

Strong and Ultra-Tough Supramolecular Hydrogel Enabled by Strain-Induced Microphase Separation

Architected hydrogels are widely used in biomedicine, soft robots, and flexible electronics while still possess big challenges in strong toughness, and shape modeling. Here, inspired with the universal hydrogen bonding interactions in biological systems, a strain-induced microphase separation path toward achieving the printable, tough supramolecular polymer hydrogels by hydrogen bond engineering is developed. Specifically, it subtly designs and fabricates the poly (N-acryloylsemicarbazide-co-acrylic acid) hydrogels with high hydrogen bond energy by phase conversion induced hydrogen bond reconstruction. The resultant hydrogels exhibited the unique strain-induced microphase separation behavior, resulting in the excellent strong toughness with, for example, an ultimate stress of 9.1 ± 0.3 MPa, strain levels of 1020 ± 126%, toughness of 33.7 ± 6.6 MJ m⁻³, and fracture energy of 171.1 ± 34.3 kJ m⁻². More importantly, the hydrogen bond engineered supramolecular hydrogels possess dynamic shape memory character, i.e shape fixing at low temperature while recovery after heating. As the proof of concept, the tailored hydrogel stents are readily manufactured by 3D printing, which showed good biocompatibility, load-bearing and drug elution, being beneficial for the biomedical applications. It is believed that the present 3D printing of the architected dynamic hydrogels with ultrahigh toughness can broaden their applications.     

A Fully Self-Healing and Highly Stretchable Liquid-Free Ionic Conductive Elastomer for Soft Ionotronics

Soft ionic conductors hold great potential for soft ionotronics, such as ionic skin, human–machine interface and soft luminescent device. However, most hydrogel and ionogel-based soft ionic conductors suffer from freezing, evaporation and liquid leakage problems, which limit their use in complex environments. Herein, a class of liquid-free ionic conductive elastomers (ICEs) is reported as an alternative soft ionic conductor in soft ionotronics. These liquid-free ICEs offer a combination of desirable properties, including extraordinary stretchability (up to 1913%), toughness (up to 1.08 MJ cm⁻³), Young's modulus (up to 0.67 MPa), rapid fully self-healing capability at room temperature, and good conductivity (up to 1.01 × 10⁻⁵ S cm⁻¹). The application of these ICEs is demonstrated by creating a wearable sensor that can detect and discriminate minimal deformations and human body movements, such as finger or elbow joint flexion, walking, running, etc. In addition, self-healing soft ionotronic devices are demonstrated to confront mechanical breakdown, such as an ionic skin and an alternating-current electroluminescent device that can reuse from damage. It is believed that these liquid-free ICEs hold great promises for applications in wearable devices and soft ionotronics.     

Wearable Biosupercapacitor: Harvesting and Storing Energy from Sweat

This work demonstrates the first example of sweat-based wearable and stretchable biosupercapacitors (BSCs), capable of generating high-power pulses from human activity. The all-printed, dual-functional, conformal BSC platform can harvest and store energy from sweat lactate. By integrating energy harvesting and storage functionalities on the same footprint of a single epidermal device, the new wearable energy system can deliver high-power pulses and be rapidly self-charged by bioenergy conversion of sweat lactate generated from human activity while simplifying the design and fabrication. The mechanical robustness and conformability of the device are realized through island-bridge patterns and strain-enduring inks. The enhanced capacitance of the BSC is realized by the synergistic effect of carbon nanotube ink with electrodeposited polypyrrole on the anode and of porous cauliflower-like platinum on the cathode. In the presence of lactate, the BSC shows high power in pulsed output and stable cycling performance. Furthermore, the wearable device can store energy and deliver high-power pulses long after the perspiration stopped. The self-charging hybrid wearable device obtained high power of 1.7 mW cm⁻² in vitro, and 343 µW cm⁻² on the body during exercise, suggesting considerable potential as a power source for the next generation of wearable electronics.     

Compliant and Robust Tissue-Like Hydrogels via Ferric Ion-Induced of Hierarchical Structure

It is a challenge to synthesize materials that possess biological tissue-like properties: strain-stiffening, robust yet compliant, sensitive, and water-rich. Herein, a ferric ion-induced salting out and coordination cross-linking strategy is presented to create a hierarchical hydrogel network, including dipole–dipole interactions connected curved chains, acrylonitrile (AN)-rich clusters, and homogeneous iron-ligand interactions. The design allows the network to deform stress-free under small strain by unfolding the curved segments with the elastic deformation of the AN-rich clusters, and sequentially breaking the dipole–dipole interactions and iron-ligand interactions from weak to strong ones under large strain. As a result, the hydrogel exhibits tissue-like mechanical properties: low elastic modulus (0.06 MPa), high strength (1.4 MPa), high toughness (5.1 MJ m⁻³), intense strain-stiffening capability (27.5 folds of stiffness enhancement), excellent self-recovery ability and fatigue resistance. Moreover, the hydrogel exhibits high water content (≈84%), good biocompatibility and multi-sensory capabilities to strain, pressure and hazardous chemicals stimuli. Therefore, this work offers a novel strategy to prepare hydrogel that can mimic the diverse functions of tissues, thereby expanding advanced applications of hydrogel in soft robotics, wearable devices, and biomedical engineering.     

Zwitterion Functionalized Graphene Oxide/Polyacrylamide/Polyacrylic Acid Hydrogels with Photothermal Conversion and Antibacterial Properties for Highly Efficient Uranium Extraction from Seawater

In this study, graphene oxide (GO) and polyacrylamide/polyacrylic acid (PAM/PAA) are used to prepare hydrogels with photothermal conversion properties for highly efficient uranium extraction from seawater. Zwitterionic 2-methacryloyloxy ethyl phosphorylcholine (MPC) is introduced in the PAM/PAA/GO hydrogel to obtain PAM/PAA/GO/MPC (PAGM), exhibiting good antibacterial properties. PAGM demonstrates efficient and specific adsorption of uranium (VI) (U(VI)). Under light conditions, the adsorption capacity of PAGM reaches 196.12 mg g⁻¹ (pH = 8, t = 600 min, C₀ = 99.8 mg L⁻¹, m/v = 0.5 g L⁻¹). The adsorption capacity is only 160.29 mg g⁻¹ under dark conditions (pH = 8, t = 600 min, C₀ = 99.8 mg L⁻¹, m/v = 0.5 g L⁻¹). The adsorption capacity of light is 22.5% higher than that of dark. The adsorption process is fitted using the Langmuir and pseudo-second-order models. Furthermore, PAGM exhibits good repeatability and stability after five adsorption–desorption cycles. PAGM exhibits a U(VI) adsorption capacity of 6.1 mg g⁻¹ after storage for one month in natural seawater. The X-ray photoelectron spectroscopy (XPS) results demonstrate that the coordination of the amino, carboxyl, and hydroxyl groups with U(VI) is the primary mechanism of U(VI) adsorption. The mechanism is confirmed through detailed density functional theory calculations. PAGM demonstrates durability, high efficiency, photothermal conversion properties, and antibacterial properties. Thus, it is a promising candidate for uranium extraction from seawater.     

Cucurbit[n]uril Supramolecular Hydrogel Networks as Tough and Healable Adhesives

Supramolecular noncovalent interactions are widely found in natural adhesion phenomena to control macroscopic adhesion and accomplish a variety of complex functions. Such supramolecular adhesives could impart the interfaces with intriguing properties, e.g., energy dissipation and self‐healing, on account of their dynamic nature. Here, we demonstrate that cucurbit[8]uril (CB[8])‐based supramolecular hydrogel networks can function as dynamic adhesives for diverse nonporous (e.g., glass, stainless steel, aluminum, copper, and titanium) and porous substrates (wood and bone). Without any surface prefunctionalization or introduction of curing agents, these CB[8] hydrogel networks can be readily applied by curing around the softening temperature, forming a tough and healable adhesive interlayer. The ability to fabricate a robust sandwich model consisting of substrate–CB[8] hydrogel network–substrate enables a number of applications including stretchable and wearable electronics, hybrid systems for biomedical devices or tissue/bone regeneration.     

Anti-Dehydration and Rapid Trigger-Detachable Multifunctional Hydrogels Promote Scarless Therapeutics of Deep Burn

There are issues and challenges in treating deep burns because of the long recovery time, frequent dressing changes, wound infection, and easy to form scar that influence aesthetics. Besides, some specific tissues are not suitable for large dressing coverage (e.g., face, perineum). Therefore, an ideal deep burn dressing should have good adhesion properties to fit the wound effectively, painless and quick replacement, resistant to infection, accelerate wound healing, reduce scarring and facilitate monitoring and diagnosis. Herein, an anti-dehydration and rapid-trigger multifunctional hydrogel dressing is prepared by interface reaction. The Pacrylamide-Formylboronicacid-Tannic acid (PAFT) hydrogels are prepared by a simple method on anti-dehydration elastomeric membrane, which is obtained using tannic acid as a dynamic cross-linking agent with 3-formylboronic acid and acrylamideunder UV light. The hydrogel exhibits a strong interfacial adhesion (892 J m⁻² ± 65 J m⁻²), which rapidly (2 min) decreases (to 180 J m⁻² ± 20 J m⁻²) when in the presence of glucose solution. The hydrogel has excellent anti-dehydration and moisturizing properties, and also exhibits superior antibacterial properties, hemostasis, and biocompatibility. This hydrogel is transparent allowing effective observation of wound transformation and therapeutics. Moreover, PAFT hydrogel accelerates the healing of deep burns and reduces scars.     

High Performance Bacterial Cellulose Organogel-Based Thermoelectrochemical Cells by Organic Solvent-Driven Crystallization for Body Heat Harvest and Self-Powered Wearable Strain Sensors

As a low-grade sustainable heat source, the human body provides a great driving force for converting heat into electric energy using thermoelectric materials, which can effectively power wearable electronics. However, the low thermoelectric conversion efficiency is not sufficient to achieve energy autonomy in the operation of wearable devices. Herein, wearable bacterial cellulose (BC) organogel-based thermoelectrochemical cells (TECs) are designed and prepared with K₄Fe(CN)₆/K₃Fe(CN)₆ as a redox couple. The addition of propylene glycol significantly improves the mechanical properties of the TECs and drives K₄Fe(CN)₆ to gradually crystallize, resulting in the concentration gradient of redox ions, which significantly enhanced the heat-to-electricity conversion efficiency (from 1.27 to 2.30 mV K⁻¹), proving that they are promising candidates for powering flexible and wearable devices in various application scenarios. The TECs are further assembled into self-powered strain sensors, which can detect the movement of the human body under various tensions and pressures in real time with high sensitivity. This indicates that the BC organogel-based TECs for self-powered strain sensors have great application potential in the wearable field.     

Polypyrrole-coated cotton fabrics prepared by electrochemical polymerization as textile counter electrode for dye-sensitized solar cells

Textile-based wearable electronics provides the combined advantages of both electronics and textiles, such as flexibility, stretchability and lightweight. Much effort has been dedicated to achieve flexible photovoltaic power for wearable electronics. Here, we have demonstrated polypyrrole (PPy) coated cotton fabrics as textile counter electrode (CE) in dye-sensitized solar cells (DSSCs). PPy is deposited on the Ni-coated cotton fabrics as catalytic material by electrochemical polymerization of pyrrole. The highly conductive PPy-coated fabric electrode with a surface resistance of 5.0 Ω sq⁻¹ shows reasonable catalytic activity for the reduction of triiodide ion. The DSSC fabricated with the PPy-coated fabric CE exhibits a power conversion efficiency as high as ∼3.83% under AM 1.5 illumination.     

3D Printing Hydrogel Scaffolds with Nanohydroxyapatite Gradient to Effectively Repair Osteochondral Defects in Rats

Osteochondral (OC) defects pose an enormous challenge with no entirely satisfactory repair strategy to date. Herein, a 3D printed gradient hydrogel scaffold with a similar structure to that of OC tissue is designed, involving a pure hydrogel-based top cartilage layer, an intermediate layer for calcified cartilage with 40% (w w⁻¹) nanohydroxyapatite (nHA) and 60% (w w⁻¹) hydrogel, and a 70/30% (w w⁻¹) nHA/hydrogel-based bottom subchondral bone layer. This study is conducted to evaluate the efficacy of the scaffold with nHA gradients in terms of its ability to promote OC defect repair. The fabricated composites are evaluated for physicochemical, mechanical, and biological properties, and then implanted into the OC defects in 56 rats. Overall, bone marrow stromal cells (BMSCs)-loaded gradient scaffolds exhibit superior repair results as compared to other scaffolds based on gross examination, micro-computed tomography (micro-CT), as well as histologic and immunohistochemical analyses, confirming the ability of this novel OC graft to facilitate simultaneous regeneration of cartilage-subchondral bone.     

Photothermal-Enhanced Uranium Extraction from Seawater: A Biomass Solar Thermal Collector with 3D Ion-Transport Networks

Access to uranium resources is critical to the sustainable development of nuclear energy. The ocean contains abundant uranium resources, but the marine biological pollution and the low concentration of uranium make it a giant challenge to extract uranium from seawater. On the foundation of selective uranium adsorption using high uranium-affinity groups, realizing the external-field improved uranium capture without extra energy consumption is highly attractive. A solar thermal collector with 3D ion-transport networks based on environmentally friendly biomass adsorption material is reported, which contains antibacterial adsorption ligands and photothermal graphene oxide. The antibacterial ability through an easy one-step reaction and the fast mass transfer caused by photothermal conversion collaboratively improve the original adsorption capacity of the hydrogel by 46.7%, reaching 9.18 mg g⁻¹ after contact with natural seawater for 14 days. This study provides a universal strategy for the design of physical-fields-enhanced hydrogel adsorbents.     

Phase-Separated Polyzwitterionic Hydrogels with Tunable Sponge-Like Structures for Stable Solar Steam Generation

Solar steam generation (SSG) through hydrogel-based evaporators has shown great promise for freshwater production. However, developing hydrogel-based evaporators with stable SSG performance in high-salinity brines remains challenging. Herein, phase-separated polyzwitterionic hydrogel-based evaporators are presented with sponge-like structures comprising interconnected pores for stable SSG performance, which are fabricated by photopolymerization of sulfobetaine methacrylate (SBMA) in water-dimethyl sulfoxide (DMSO) mixed solvents. It is shown that driven by competitive adsorption, the structures of the resulting poly(sulfobetaine methacrylate) (PSBMA) hydrogels can be readily tuned by the volume ratio of DMSO to achieve phase separation. The optimized phase-separated PSBMA hydrogels, combining the unique anti-polyelectrolyte effects of polyzwitterionic hydrogels, demonstrate a rapid water transport capability in brines. After introducing photothermal polypyrrole particles on the surface of the phase-separated PSBMA hydrogel evaporators, a stable water evaporation rate of ≈2.024 kg m⁻² h⁻¹ and high solar-to-vapor efficiency of ≈97.5% in a 3.5 wt.% brine are obtained under simulated solar light irradiation (1.0 kW m⁻²). Surprisingly, the evaporation rates remain stable even under high-intensity solar irradiation (2.0 kW m⁻²). It is anticipated that the polyzwitterionic hydrogel evaporators with sponge-like porous structures will contribute to developing SSG technology for high-salinity seawater applications.     

Scale up the collection area of luminescent solar concentrators towards metre‐length flexible waveguiding photovoltaics

Luminescent solar concentrators (LSCs) are cost‐effective components easily integrated in photovoltaics (PV) that can enhance solar cells' performance and promote the integration of PV architectural elements into buildings, with unprecedented possibilities for energy harvesting in façade design, urban furnishings and wearable fabrics. The devices' performance is dominated by the concentration factor (F), which is higher in cylindrical LSCs compared with planar ones (with equivalent collection area and volume). The feasibility of fabricating long‐length LSCs has been essentially limited up to ten of centimetres with F < 1. We use a drawing optical fibre facility to easily scale up large‐area LSCs (length up to 2.5 m) based on bulk and hollow‐core plastic optical fibres (POFs). The active layers used to coat the bulk fibres or fill the hollow‐core ones are Rhodamine 6G‐ or Eu³⁺‐doped organic–inorganic hybrids. For bulk‐coated LSCs, light propagation occurs essentially at the POFs, whereas for hollow‐core device light is also guided within the hybrid. The lower POFs' attenuation (~0.1 m⁻¹) enables light propagation in the total fibre length (2.5 m) for bulk‐coated LSCs with maximum optical conversion efficiency (η_opt) and F of 0.6% and 6.5, respectively. For hollow‐core LSCs, light propagation is confined to shorter distances (6–9 × 10⁻² m) because of the hybrids' attenuation (1–15 m⁻¹). The hollow‐core optimised device displays η_opt = 72.4% and F = 12.3. The F values are larger than the best ones reported in the literature for large‐area LSCs (F = 4.4), illustrating the potential of this approach for the development of lightweight flexible high‐performance waveguiding PV. Copyright © 2016 John Wiley & Sons, Ltd.     

Asymmetric Sandwich Janus Structure for High-Performance Textile-Based Thermo–Hydroelectric Generators Toward Human Health Monitoring

Textile-based generators that can convert low-grade energy from the human body or environment into sustainable electricity have generated immense scientific interest in self-powered wearable applications. However, their low power density and environmental suitability have extremely restricted their portable applications in complex and mutable environments. Herein, an asymmetric sandwich structure between molybdenum disulfide (MoS₂)-carbonized silks (MCs) and MoS₂/MXene–Cottons (MMCs) to construct efficient thermo–hydroelectric generators (THEGs) that synergistically harvest heat-moisture energy to generate considerable electricity is rationally designed. Notably, the large surface area of MoS₂/MXene van der Waals heterojunctions (vdWhs) enables efficient charge collection, and the vertical MoS₂ nanosheet arrays supply abundant nanochannels for a highly efficient hydration effect, generating an output power density of 32.26 µW cm⁻² after wetting with deionized water. Combined with the sensitive temperature recognition ability with a Seebeck coefficient of 23.5 µV K⁻¹, the application possibilities of these prepared THEGs in the mutual conversion of fingertip temperature/language, and the monitoring of the human physiological state is foresee.