Lignin,the most abundant natural aromatic polymer globally,has garnered considerable interest due to its rich and diverse active functional groups and its antioxidant,antimicrobial,and adhesive properties.Recent resea...Lignin,the most abundant natural aromatic polymer globally,has garnered considerable interest due to its rich and diverse active functional groups and its antioxidant,antimicrobial,and adhesive properties.Recent research has significantly improved the performance of lignin-based hydrogels,suggesting their substantial potential in fields such as biomedicine,environmental science,and agriculture.This paper reviews the process of lignin extraction,systematically introduces synthesis strategies for preparing lignin-based hydrogels,and discusses the current state of research on these hydrogels in biomedical and environmental protection fields.It concludes by identifying the existing challenges in lignin hydrogel research and envisioning future prospects and development trends.展开更多
Converting body heat into electricity presents an appealing route for sustainably powering wearable electronics;however,conventional thermoelectric materials face significant drawbacks,including high ionic concentrati...Converting body heat into electricity presents an appealing route for sustainably powering wearable electronics;however,conventional thermoelectric materials face significant drawbacks,including high ionic concentrations,toxicity,and limited thermoelectric efficiency.Here,we report an ionic thermoelectric hydrogel designed through precise supramolecular chemistry,utilizing dual molecular interactions,host-vip complexation ofα-cyclodextrin(α-CD)with I_(3)^(-)ions and hydrogen bonding between polyvinyl alcohol(PVA)polymer chains and I_(3)^(-).This molecularly tailored approach markedly amplifies thermoelectric performance,achieving a high thermopower of 2.21 mV/K and a tenfold enhancement in peak power output at an exceptionally low iodine concentration(10 mmol/L I^(-)+2.5 mmol/L I_(3)^(-)).The hydrogel maintains excellent biocompatibility and mechanical robustness,suitable for direct skin contact.Demonstrated applications include flexible thermoelectric devices generating nearly 100 mV from body heat and sensor arrays capable of motion and spatial temperature sensing.These results underscore the substantial potential of supramolecularly designed ionic thermoelectric hydrogels for wearable energy harvesting,personalized healthcare monitoring,and advanced human-computer interfaces.展开更多
Burn infection is one of the most common and severe complications in burn patients and a major factor contributing to high mortality rates.The loss of skin barrier function and the immunosuppressive state following bu...Burn infection is one of the most common and severe complications in burn patients and a major factor contributing to high mortality rates.The loss of skin barrier function and the immunosuppressive state following burns make patients highly susceptible to wound infections,which can progress to systemic sepsis.Although burn wounds are initially sterile,they are rapidly colonized by Gram-positive bacteria(e.g.,Staphylococcus aureus)within a short period,followed by colonization with Gram-negative bacteria(e.g.,Pseudomonas aeruginosa),thereby increasing therapeutic challenges.Current clinical management relies on a multidisciplinary collaborative approach,combining conventional antibiotics,emerging therapies,and comprehensive care strategies.Among these methods,early intervention,precise treatment administration,and prevention and control are critical to improving patient survival and prognosis.In recent years,drug-loaded hydrogels,as a class of wound repair materials characterized by biocompatibility,controlled drug release,and multifunctional integration,have demonstrated significant advantages in the treatment of burn infections.They can effectively inhibit pathogenic microorganisms,alleviate inflammation,and promote tissue regeneration.This review systematically summarizes recent research advances in the application of drug-loaded hydrogels for the treatment of infected burn wounds,aiming to provide a reference for their further development and clinical translation.展开更多
The osteochondral(OC)interface exhibits a mineral gradient,varying in thickness by several hundred micrometers across different species.Disruptions in this interface damage OC tissues,leading to osteoarthritis.The nat...The osteochondral(OC)interface exhibits a mineral gradient,varying in thickness by several hundred micrometers across different species.Disruptions in this interface damage OC tissues,leading to osteoarthritis.The natural architecture and composition of native OC interfaces can be replicated using biomaterial scaffolds via regenerative engineering approaches.A novel one-step bioextrusion process was employed to fabricate a unitary synthetic graft(USG),which mimics the native OC interface’s mineral concentration gradient.This novel USG is composed of an agarose-based cartilage layer and a bone layer,consisting of agarose enriched with 20%(200 g/L)hydroxyapatite.The USG features a gradient interface with mineral concentrations transitioning from 0%to 20%(mass fraction),mimicking the transition between the cartilage and bone.Thermogravimetric analysis revealed that the gradient transition lengths of the graft and native OC tissue harvested from bovine knees were similar((647±21)vs.(633±124)μm).The linear viscoelastic properties of the grafts,which were evaluated using strain sweep and frequency sweep tests with oscillatory shear,indicated a dominant storage modulus over loss modulus similar to that of native OC tissues.The compressive and stress relaxation behaviors of the USGs demonstrated that the graft maintained structural integrity under mechanical stress.Viability assays performed after bioextrusion showed that chondrocytes and human fetal osteoblast cells successfully integrated and survived within their designated regions of the graft.The novel USGs exhibit properties similar to native OC tissue and are promising candidates for regenerating OC defects and restoring knee joint functionality.展开更多
In the current transformative era of biomedicine,hydrogels have established their presence in biomaterials due to their superior biocompatibility,tuneability and resemblance with native tissue.However,hydrogels typica...In the current transformative era of biomedicine,hydrogels have established their presence in biomaterials due to their superior biocompatibility,tuneability and resemblance with native tissue.However,hydrogels typically exhibit poor conductivity due to their hydrophilic polymer structure.Electrical conductivity provides an important enhancement to the properties of hydrogel-based systems in various biomedical applications such as drug delivery and tissue engineering.Consequently,researchers are developing combinatorial strategies to develop electrically responsive“SMART”systems to improve the therapeutic efficacy of biomolecules.Electrically conductive hydrogels have been explored for various drug delivery applications,enabling higher loading of therapeutic cargo with on-demand delivery.This review emphasizes the properties,mechanisms,fabrication techniques and recent advancements of electrically responsive“SMART”systems aiding on-site drug delivery applications.Additionally,it covers prospects for the successful translation of these systems into clinical research.展开更多
Despite the promising progress in conductive hydrogels made with pure conducting polymer,great challenges remain in the interface adhesion and robustness in longterm monitoring.To address these challenges,Prof.Seung H...Despite the promising progress in conductive hydrogels made with pure conducting polymer,great challenges remain in the interface adhesion and robustness in longterm monitoring.To address these challenges,Prof.Seung Hwan Ko and Taek-Soo Kim’s team introduced a laserinduced phase separation and adhesion method for fabricating conductive hydrogels consisting of pure poly(3,4-ethylenedioxythiophene):polystyrene sulfonate on polymer substrates.The laser-induced phase separation and adhesion treated conducting polymers can be selectively transformed into conductive hydrogels that exhibit wet conductivities of 101.4 S cm^(−1) with a spatial resolution down to 5μm.Moreover,they maintain impedance and charge-storage capacity even after 1 h of sonication.The micropatterned electrode arrays demonstrate their potential in long-term in vivo signal recordings,highlighting their promising role in the field of bioelectronics.展开更多
Hydrogel-based flexible sensors are emerging as ideal candidates for wearable devices and soft robotics.However,most current hydrogels possess limited physicochemical properties,which hinder their practical applicatio...Hydrogel-based flexible sensors are emerging as ideal candidates for wearable devices and soft robotics.However,most current hydrogels possess limited physicochemical properties,which hinder their practical application in long-term and complex scenarios.Herein,inspired by the unique structure of the barnacle,we design multifunctional poly(DMAPA-co-PHEA)hydrogels(CP hydrogels)by employing multiple physical crosslinks in the presence of Ag nanoparticles and NaCl additives.Owing to the synergistic effect of cation-πinteractions,hydrophobic interactions,and ionic bonds,the CP hydrogels exhibit high stretchability(strain up to 1430%),strong adhesion(22.8 kPa),satisfactory antibacterial activity,stable anti-icing ability(<20 kPa after 20 icing-deicing cycles),and high electrical conductivity(18.5 mS/cm).Additionally,the CP hydrogels show fast and sensitive responsiveness and cycling stability and can attach directly to human skin to accurately detect both human motions and tiny physiological signals as a flexible wearable sensor.Collectively,this work significantly contributes a straightforward and efficient design strategy for the development of multifunctional hydrogels,broadening their application scenarios.展开更多
The performance of hydrogel radical polymerization under ambient conditions is a major challenge because oxygen is an effective radical quencher and the steps to remove or neutralize it are time consuming and laboriou...The performance of hydrogel radical polymerization under ambient conditions is a major challenge because oxygen is an effective radical quencher and the steps to remove or neutralize it are time consuming and laborious.A self-initiating system consisting of transition metals and acetylacetone has been successfully developed.The system is capable of initiating free radical polymerization of hydrogels at room temperature under aerobic conditions,which is attributed to carbon radicals generated by the oxidation of acetylacetone.Some of these carbon radicals reduce oxygen to generate hydroxyl radicals,which together induce self-coagulation of hydrogels.The polymerization system was effective for a variety of monomer and hydrogel swelling and shrinking schemes,and the reaction remained successful when exposed to saturated oxygen.In conclusion,the results demonstrate that the present strategy is an effective approach to addressing the challenge of deoxygenation in polymer synthesis,and provides a convenient method for synthesizing multifunctional hydrogels under ambient conditions.展开更多
Soft self-healing materials are promising candidates for flexible electronic devices due to their excep-tional compatibility,extensibility,and self-restorability.Generally,these materials suffer from low tensile stren...Soft self-healing materials are promising candidates for flexible electronic devices due to their excep-tional compatibility,extensibility,and self-restorability.Generally,these materials suffer from low tensile strength and susceptibility to fracture because of the restricted microstructure design.Herein,we pro-pose a hydrothermal-freeze-thaw method to construct high-strength self-healing hydrogels with even in-terconnected networks and distinctive wrinkled surfaces.The integration of the wrinkled outer surface with the three-dimensional internal network confers the self-healing hydrogel with enhanced mechan-ical strength.This hydrogel achieves a tensile strength of 223 kPa,a breaking elongation of 442%,an adhesion strength of 57.6 kPa,and an adhesion energy of 237.2 J m-2.Meanwhile,the hydrogel demon-strates impressive self-repair capability(repair efficiency:93%).Moreover,the density functional theory(DFT)calculations are used to substantiate the stable existence of hydrogen bonding between the PPPBG hydrogel and water molecules which ensures the durability of the PPPBG hydrogel for long-term applica-tion.The measurements demonstrate that this multifunctional hydrogel possesses the requisite sensitivity and durability to serve as a strain sensor,which monitors a spectrum of motion signals including subtle vocalizations,pronounced facial expressions,and limb articulations.This work presents a viable strategy for healthcare monitoring,soft robotics,and interactive electronic skins.展开更多
Achieving continuous motions typically requires dynamic external stimuli for cyclic deformation,or crafted geometries with intricate modules to form a self-regulated feedback loop upon static stimulation.It is still a...Achieving continuous motions typically requires dynamic external stimuli for cyclic deformation,or crafted geometries with intricate modules to form a self-regulated feedback loop upon static stimulation.It is still a grand challenge to realize self-sustained motion in soft robots subject to unchanging environment,without complex geometry or a control module.In this work,we report soft robots based on an anisotropic cylindrical hydrogel showing self-regulated,continuous rolling motions under constant light irradiation.The robots are animated by mirror-symmetry-breaking induced by photothermal strain gradient.The self-sustained motion is attributed to the fast and reversible deformation of the gel and the autonomous refresh of the irradiated region during the rolling motion.The hydrogel robots can reach a rolling speed of 1.27 mm·s^(-1)on a horizonal surface and even climb a ramp of 18°at a speed of 0.57 mm·s^(-1)in an aqueous environment.Furthermore,the hydrogel robots can overcome an obstacle,with rolling direction controllable through irradiation angle of the light and local irradiation on selective regions.This work suggests a facile strategy to develop hydrogel robots and may provide unforeseen inspirations for the design of self-regulated soft robots by using other intelligent materials.展开更多
Smart actuators and wearable and implantable devices have attracted much attention in healthcare and environmental sensing.Flexible electronic and ionic materials are the two main approaches used to construct these de...Smart actuators and wearable and implantable devices have attracted much attention in healthcare and environmental sensing.Flexible electronic and ionic materials are the two main approaches used to construct these devices.Among them,hydrogel-based ionic materials offer unique advantages,such as biocompatibility and adaptable mechanical properties.However,ionic hydrogels encounter challenges in achieving wirelessly powered and noncontact sensing.To address this,we introduce MXene nanosheets to construct ionotronic hydrogels.Leveraging the rich surface charges and electronic conductivity of MXene nanosheets,ionotronic hydrogels can harvest vibrational and electromagnetic waves as electrical energy and enable noncontact sensing.Under ultrasound,it can continuously generate voltages up to 85 V and light up lightemitting diodes,promising wireless charging of implanted devices.In addition,it achieves an absorption coefficient of 0.2 for 915 MHz electromagnetic waves,enabling noncontact sensing through radio frequency identification.Notably,the physically crosslinked network of the MXenebased hydrogels maintained structural and performance stability under ultrasonic stimulation and exhibited self-healing properties.Even when cut into two halves,the self-healing hydrogel fully regenerates its original performance.This study provides insight into the development of ionotronic hydrogels for wirelessly powered and noncontact sensing in smart actuators and wearable and implantable applications.展开更多
When a cracked hydrogel sample immersed in water is stretched,a swelling zone near the crack tip emerges.Within the swelling zone,water diffusion occurs and swells the hydrogel.Outside the swelling zone,water diffusio...When a cracked hydrogel sample immersed in water is stretched,a swelling zone near the crack tip emerges.Within the swelling zone,water diffusion occurs and swells the hydrogel.Outside the swelling zone,water diffusion is negligible,and the material behaves like an incompressible elastomer.Since water diffusion is a time-dependent process,the size of the swelling zone changes with time.As time evolves,the size of the swelling zone grows until to the size of the hydrogel sample.There exists a competition between the size of the swelling zone and the size of the hydrogel sample,which results in complex rate-dependent fracture behavior of hydrogel.In this article,the competition effect is studied theoretically and numerically.We find that the hydrogel undergoes three stages gradually:small-scale swelling,large-scale swelling,and equilibrium as the size of the swelling zone approaches the size of the hydrogel sample.In the stage of small-scale swelling,the first invariant of stretch at the notch tip I1notch increases with the decrease of the stretch rate.In the stage of large-scale swelling,I1notch increases first and then decreases with the decrease of stretch rate.In the stage of equilibrium,the effect of water diffusion is negligible,and I1notch is independent of stretch rate.This work reveals the connection between the stretch rate,the size of the swelling zone,and the crack tip quantity I1notch,which is used to establish the fracture criterion and predict rate-dependent fracture of hydrogel.Particularly,the previous works on different trends of rate-dependent behavior of hydrogel can be unified in this work,when both small-scale swelling and large-scale swelling are considered.展开更多
The integration of 3D-printed hydrogels in soft robotics enables the creation of flexible,adaptable,and biocompatible systems.Hydrogels,with their high-water content and responsiveness to stimuli,are suitable for actu...The integration of 3D-printed hydrogels in soft robotics enables the creation of flexible,adaptable,and biocompatible systems.Hydrogels,with their high-water content and responsiveness to stimuli,are suitable for actuators,sensors,and robotic systems that require safe interaction and precise manipulation.Unlike traditional techniques,3D printing offers enhanced capabilities in tailoring structural complexity,resolution,and integrated functionality,enabling the direct fabrication of hydrogel systems with programmed mechanical and functional properties.In this perspective,we explore the evolving role of 3D-printed hydrogels in soft robotics,covering their material composition,fabrication techniques,and diverse applications.We highlight advancements in hydrogel-based actuators,sensors,and robots,emphasizing their ability to perform intricate motions.In addition,we discuss challenges like mechanical robustness,scalability,and integration as well as the potential of hydrogels in soft robotics and explore future directions for their development.展开更多
Traditional cancer therapies have limitations like poor efficacy on advanced tumors,healthy tissue damage,side effects,and drug resistance,creating an urgent need for new strategies.Hydrogels have good biocompatibilit...Traditional cancer therapies have limitations like poor efficacy on advanced tumors,healthy tissue damage,side effects,and drug resistance,creating an urgent need for new strategies.Hydrogels have good biocompatibility and controlled release,while extracellular vesicles(EVs)enable targeting and bioactive transport.This review systematically summarizes hydrogels and EVs,focusing on the construction of hydrogel-EV delivery system,key influencing factors,drug delivery mechanisms,and tumor therapy apps,clarifying their synergies.The system overcomes single-carrier flaws,construction methods/key factors affect performance,preclinical studies have confirmed efficacy in multiple therapies,but large-scale production and in vivo stability challenges remain,yet it promises to overcome the limits of traditional therapy for precision oncology.展开更多
Xerostomia(dry mouth)is frequently experienced by patients treated with radiotherapy for head and neck cancers or with Sjögren’s syndrome,with no permanent cure existing for this debilitating condition.To this e...Xerostomia(dry mouth)is frequently experienced by patients treated with radiotherapy for head and neck cancers or with Sjögren’s syndrome,with no permanent cure existing for this debilitating condition.To this end,in vitro platforms are needed to test therapies directed at salivary(fluid-secreting)cells.However,since these are highly differentiated secretory cells,the maintenance of their differentiated state while expanding in numbers is challenging.In this study,the efficiency of three reversible thermo-ionically crosslinked gels:(1)alginate–gelatin(AG),(2)collagen-containing AG(AGC),and(3)hyaluronic acid-containing AG(AGHA),to recapitulate a native-like environment for human salivary gland(SG)cell expansion and 3D spheroid formation was compared.Although all gels were of mechanical properties comparable to human SG tissue(~11 kPa)and promoted the formation of 3D spheroids,AGHA gels produced larger(>100 cells/spheroid),viable(>93%),proliferative,and well-organized 3D SG spheroids while spatially and temporally maintaining the high expression of key SG proteins(aquaporin-5,NKCC1,ZO-1,α-amylase)for 14 days in culture.Moreover,the spheroids responded to agonist-induced stimulation by increasingα-amylase secretory granules.Here,we propose alternative lowcost,reproducible,and reversible AG-based 3D hydrogels that allow the facile and rapid retrieval of intact,highly viable 3D-SG spheroids.展开更多
All-season thermal management with zero energy consumption and emissions is more crucial to global decarbonization over traditional energy-intensive cooling/heating systems.However,the static single thermal management...All-season thermal management with zero energy consumption and emissions is more crucial to global decarbonization over traditional energy-intensive cooling/heating systems.However,the static single thermal management for cooling or heating fails to self-regulate the temperature in dynamic seasonal temperature condition.Herein,inspired by the dual-temperature regulation function of the fur color changes on the backs and abdomens of penguins,a smart thermal management composite hydrogel(PNA@H-PM Gel)system was subtly created though an"on-demand"dual-layer structure design strategy.The PNA@H-PM Gel system features synchronous solar and thermal radiation modulation as well as tunable phase transition temperatures to meet the variable seasonal thermal requirements and energy-saving demands via self-adaptive radiative cooling and solar heating regulation.Furthermore,this system demonstrates superb modulations of both the solar reflectance(ΔR=0.74)and thermal emissivity(ΔE=0.52)in response to ambient temperature changes,highlighting efficient temperature regulation with average radiative cooling and solar heating effects of 9.6℃in summer and 6.1℃in winter,respectively.Moreover,compared to standard building baselines,the PNA@H-PM Gel presents a more substantial energy-saving cooling/heating potentials for energy-efficient buildings across various regions and climates.This novel solution,inspired by penguins in the real world,will offer a fresh approach for producing intelligent,energy-saving thermal management materials,and serve for temperature regulation under dynamic climate conditions and even throughout all seasons.展开更多
Traditional hydrogels are inevitably damaged during practical applications,resulting in a gradual deterioration of their functional efficacy.A primary strategy to address this issue involves developing hydrogels with ...Traditional hydrogels are inevitably damaged during practical applications,resulting in a gradual deterioration of their functional efficacy.A primary strategy to address this issue involves developing hydrogels with inherent self-healing properties.In this study,we report the synthesis of self-healing polyacrylate hydrogels that integrate zwitterions,hydrophilic nano-silica and aluminum ions.Due to the synergistic effect of multiple hydrogen bonds,coordination bonds and electrostatic interactions,the tensile strength of the hydrogel is enhanced from 15.1 to 162.6 kPa.Moreover,the electrical resistance and tensile strength of the hydrogel can almost recover to its initial values after 20 min of healing at room temperature,exhibiting remarkable self-healing performance.Furthermore,the zwitterionic polyacrylate hydrogel serves as a wearable sensor with the capability of accurately response to the bending and stretching of human joints,exhibting a gauge factor of 1.87 under tensile strain ranging from 80% to 100%.Even after being freezed at-20℃ for 3 h,the zwitterionic polyacrylate hydrogel retains its exceptional writing performance.In conclusion,the hydrogels developed in this study demonstrate significant potential for wearable electronics applications.展开更多
With several favorable properties,including flexibility,biocompatibility,and conductivity,conductive hydrogels are one of the most promising flexible sensing materials and are expected to be used in areas such as wear...With several favorable properties,including flexibility,biocompatibility,and conductivity,conductive hydrogels are one of the most promising flexible sensing materials and are expected to be used in areas such as wearable devices,health monitoring,and electronic skin.However,water in hydrogels freezes at sub-zero temperatures,which greatly affects the performance of hydrogels at low temperatures.Therefore,it remains a challenge to prepare conductive hydrogels that can maintain their performance at low temperatures.In this work,we developed a series of polyoxometalate-based anti-freezing hydrogels with high conductivity by constructing a semi-interpenetrating network using polyacrylamide and sodium alginate,and then introducing H_(3)PW_(12)O_(40)(HPW)and glycerol into it via a facile soaking strategy.Among the obtained anti-freezing hydrogels,PSWG-50%hydrogel has the proton conductivity of 0.325 S·cm^(−1) at room temperature and can maintain high proton conductivity over a wide temperature range from−20 to 65℃.Based on these advantages,PSWG-50%hydrogel has been used in flexible sensors to monitor human movement,such as limb bending.Whether in mild or cold environments,PSWG-50%hydrogel shows great potential in the field of flexible sensor.展开更多
Enhancing gelatin methacryloyl(GelMA)hydrogel mechanics without compromising biocompatibility remains challenging,as conventional chemical crosslinking often disrupts degradation behavior.A cooling-induced entan-gleme...Enhancing gelatin methacryloyl(GelMA)hydrogel mechanics without compromising biocompatibility remains challenging,as conventional chemical crosslinking often disrupts degradation behavior.A cooling-induced entan-glement strategy effectively improves mechanical performance while preserving biological properties;however,its underlying mechanisms remain unclear.This study demonstrates that extended cooling durations significantly enhance the mechanical properties of GelMA hydrogels.Microstructural analyses reveal cooling-induced forma-tion of compact polymer networks with reduced mesh sizes.Molecular dynamics(MD)simulations confirm that the cooling process promotes topological entanglements that govern mechanical reinforcement.Guided by these insights,we propose a theoretical model to predict the stress responses of GelMA hydrogels under various cooling durations,establishing quantitative correlations between entanglement mechanisms and mechanical outcomes.This study provides a fundamental understanding of the interplay between cooling conditions,microstructure,and mechanical performance,offering a robust framework for designing GelMA hydrogels with optimized me-chanical properties for advanced biomedical applications.展开更多
Hygroscopic hydrogel is a promising evaporativecooling material for high-power passive daytime cooling with water self-regeneration.However,undesired solar and environmental heating makes it a challenge to maintain su...Hygroscopic hydrogel is a promising evaporativecooling material for high-power passive daytime cooling with water self-regeneration.However,undesired solar and environmental heating makes it a challenge to maintain sub-ambient daytime cooling.While different strategies have been developed to mitigate heat gains,they inevitably sacrifice the evaporation and water regeneration due to highly coupled thermal and vapor transport.Here,an anisotropic synergistically performed insulation-radiation-evaporation(ASPIRE)cooler is developed by leveraging a dual-alignment structure both internal and external to the hydrogel for coordinated thermal and water transport.The ASPIRE cooler achieves an impressive average sub-ambient cooling temperature of~8.2℃ and a remarkable peak cooling power of 311 W m^(-2)under direct sunlight.Further examining the cooling mechanism reveals that the ASPIRE cooler reduces the solar and environmental heat gains without comprising the evaporation.Moreover,self-sustained multi-day cooling is possible with water self-regeneration at night under both clear and cloudy days.The synergistic design provides new insights toward high-power,sustainable,and all-weather passive cooling applications.展开更多
基金supported by the National Natural Science Foundation of China(21706052,22278114)Natural Science Foundation of Henan Province(242300421575).
文摘Lignin,the most abundant natural aromatic polymer globally,has garnered considerable interest due to its rich and diverse active functional groups and its antioxidant,antimicrobial,and adhesive properties.Recent research has significantly improved the performance of lignin-based hydrogels,suggesting their substantial potential in fields such as biomedicine,environmental science,and agriculture.This paper reviews the process of lignin extraction,systematically introduces synthesis strategies for preparing lignin-based hydrogels,and discusses the current state of research on these hydrogels in biomedical and environmental protection fields.It concludes by identifying the existing challenges in lignin hydrogel research and envisioning future prospects and development trends.
基金supported by the National Natural Science Foundation of China(22271110)the Natural Science Founda-tion of Hubei Province(2022CFA031)。
文摘Converting body heat into electricity presents an appealing route for sustainably powering wearable electronics;however,conventional thermoelectric materials face significant drawbacks,including high ionic concentrations,toxicity,and limited thermoelectric efficiency.Here,we report an ionic thermoelectric hydrogel designed through precise supramolecular chemistry,utilizing dual molecular interactions,host-vip complexation ofα-cyclodextrin(α-CD)with I_(3)^(-)ions and hydrogen bonding between polyvinyl alcohol(PVA)polymer chains and I_(3)^(-).This molecularly tailored approach markedly amplifies thermoelectric performance,achieving a high thermopower of 2.21 mV/K and a tenfold enhancement in peak power output at an exceptionally low iodine concentration(10 mmol/L I^(-)+2.5 mmol/L I_(3)^(-)).The hydrogel maintains excellent biocompatibility and mechanical robustness,suitable for direct skin contact.Demonstrated applications include flexible thermoelectric devices generating nearly 100 mV from body heat and sensor arrays capable of motion and spatial temperature sensing.These results underscore the substantial potential of supramolecularly designed ionic thermoelectric hydrogels for wearable energy harvesting,personalized healthcare monitoring,and advanced human-computer interfaces.
基金Supported by Natural Science Foundation of Guangxi(2025GXNSFHA069111,2020GXNSFAA159033,2019GXNSFAA245078)National Undergraduate Innovation and Entrepreneurship Training Program(202410601054).
文摘Burn infection is one of the most common and severe complications in burn patients and a major factor contributing to high mortality rates.The loss of skin barrier function and the immunosuppressive state following burns make patients highly susceptible to wound infections,which can progress to systemic sepsis.Although burn wounds are initially sterile,they are rapidly colonized by Gram-positive bacteria(e.g.,Staphylococcus aureus)within a short period,followed by colonization with Gram-negative bacteria(e.g.,Pseudomonas aeruginosa),thereby increasing therapeutic challenges.Current clinical management relies on a multidisciplinary collaborative approach,combining conventional antibiotics,emerging therapies,and comprehensive care strategies.Among these methods,early intervention,precise treatment administration,and prevention and control are critical to improving patient survival and prognosis.In recent years,drug-loaded hydrogels,as a class of wound repair materials characterized by biocompatibility,controlled drug release,and multifunctional integration,have demonstrated significant advantages in the treatment of burn infections.They can effectively inhibit pathogenic microorganisms,alleviate inflammation,and promote tissue regeneration.This review systematically summarizes recent research advances in the application of drug-loaded hydrogels for the treatment of infected burn wounds,aiming to provide a reference for their further development and clinical translation.
基金supported by the School of Engineering and Digital Sciences of Nazarbayev University,Astana,Kazakhstan(to CE)。
文摘The osteochondral(OC)interface exhibits a mineral gradient,varying in thickness by several hundred micrometers across different species.Disruptions in this interface damage OC tissues,leading to osteoarthritis.The natural architecture and composition of native OC interfaces can be replicated using biomaterial scaffolds via regenerative engineering approaches.A novel one-step bioextrusion process was employed to fabricate a unitary synthetic graft(USG),which mimics the native OC interface’s mineral concentration gradient.This novel USG is composed of an agarose-based cartilage layer and a bone layer,consisting of agarose enriched with 20%(200 g/L)hydroxyapatite.The USG features a gradient interface with mineral concentrations transitioning from 0%to 20%(mass fraction),mimicking the transition between the cartilage and bone.Thermogravimetric analysis revealed that the gradient transition lengths of the graft and native OC tissue harvested from bovine knees were similar((647±21)vs.(633±124)μm).The linear viscoelastic properties of the grafts,which were evaluated using strain sweep and frequency sweep tests with oscillatory shear,indicated a dominant storage modulus over loss modulus similar to that of native OC tissues.The compressive and stress relaxation behaviors of the USGs demonstrated that the graft maintained structural integrity under mechanical stress.Viability assays performed after bioextrusion showed that chondrocytes and human fetal osteoblast cells successfully integrated and survived within their designated regions of the graft.The novel USGs exhibit properties similar to native OC tissue and are promising candidates for regenerating OC defects and restoring knee joint functionality.
基金the Ministry of Human Resource and Development (MHRD) Government of India for funding
文摘In the current transformative era of biomedicine,hydrogels have established their presence in biomaterials due to their superior biocompatibility,tuneability and resemblance with native tissue.However,hydrogels typically exhibit poor conductivity due to their hydrophilic polymer structure.Electrical conductivity provides an important enhancement to the properties of hydrogel-based systems in various biomedical applications such as drug delivery and tissue engineering.Consequently,researchers are developing combinatorial strategies to develop electrically responsive“SMART”systems to improve the therapeutic efficacy of biomolecules.Electrically conductive hydrogels have been explored for various drug delivery applications,enabling higher loading of therapeutic cargo with on-demand delivery.This review emphasizes the properties,mechanisms,fabrication techniques and recent advancements of electrically responsive“SMART”systems aiding on-site drug delivery applications.Additionally,it covers prospects for the successful translation of these systems into clinical research.
基金supported by the National Natural Science Foundation of China(52475610)Zhejiang Provincial Natural Science Foundation of China(LDQ24E050001).
文摘Despite the promising progress in conductive hydrogels made with pure conducting polymer,great challenges remain in the interface adhesion and robustness in longterm monitoring.To address these challenges,Prof.Seung Hwan Ko and Taek-Soo Kim’s team introduced a laserinduced phase separation and adhesion method for fabricating conductive hydrogels consisting of pure poly(3,4-ethylenedioxythiophene):polystyrene sulfonate on polymer substrates.The laser-induced phase separation and adhesion treated conducting polymers can be selectively transformed into conductive hydrogels that exhibit wet conductivities of 101.4 S cm^(−1) with a spatial resolution down to 5μm.Moreover,they maintain impedance and charge-storage capacity even after 1 h of sonication.The micropatterned electrode arrays demonstrate their potential in long-term in vivo signal recordings,highlighting their promising role in the field of bioelectronics.
基金financial support from the Guangdong Basic and Applied Basic Research Foundation(No.2023A1515012218)Macao Science and Technology Development Fund(Nos.FDCT 0009/2020/AMJ,0027/2023/RIB1)+1 种基金National Natural Science Foundation of China(No.32301104)Fundamental Research Funds for the Central Universities,Sun Yat-sen University(No.23ptpy165).
文摘Hydrogel-based flexible sensors are emerging as ideal candidates for wearable devices and soft robotics.However,most current hydrogels possess limited physicochemical properties,which hinder their practical application in long-term and complex scenarios.Herein,inspired by the unique structure of the barnacle,we design multifunctional poly(DMAPA-co-PHEA)hydrogels(CP hydrogels)by employing multiple physical crosslinks in the presence of Ag nanoparticles and NaCl additives.Owing to the synergistic effect of cation-πinteractions,hydrophobic interactions,and ionic bonds,the CP hydrogels exhibit high stretchability(strain up to 1430%),strong adhesion(22.8 kPa),satisfactory antibacterial activity,stable anti-icing ability(<20 kPa after 20 icing-deicing cycles),and high electrical conductivity(18.5 mS/cm).Additionally,the CP hydrogels show fast and sensitive responsiveness and cycling stability and can attach directly to human skin to accurately detect both human motions and tiny physiological signals as a flexible wearable sensor.Collectively,this work significantly contributes a straightforward and efficient design strategy for the development of multifunctional hydrogels,broadening their application scenarios.
基金funded by the National Key R&D Program of China(No.2022YFF0904000)Cross-disciplinary Innovation Project of Jilin University(No.JLUXKJC2021ZZ01)the financial support from National Natural Science Foundation of China(No.62201497).
文摘The performance of hydrogel radical polymerization under ambient conditions is a major challenge because oxygen is an effective radical quencher and the steps to remove or neutralize it are time consuming and laborious.A self-initiating system consisting of transition metals and acetylacetone has been successfully developed.The system is capable of initiating free radical polymerization of hydrogels at room temperature under aerobic conditions,which is attributed to carbon radicals generated by the oxidation of acetylacetone.Some of these carbon radicals reduce oxygen to generate hydroxyl radicals,which together induce self-coagulation of hydrogels.The polymerization system was effective for a variety of monomer and hydrogel swelling and shrinking schemes,and the reaction remained successful when exposed to saturated oxygen.In conclusion,the results demonstrate that the present strategy is an effective approach to addressing the challenge of deoxygenation in polymer synthesis,and provides a convenient method for synthesizing multifunctional hydrogels under ambient conditions.
基金supported by the National Natural Science Foundation of China(Nos.U21A6004,U21A20172,61804091,21574076,and U1510121)the Science and Technology Major Project of Shanxi(No.202101030201022)+1 种基金the Fundamental Research Program of Shanxi Province(No.202103021223019)the Open Fund of the Key Lab of Organic Optoelectronics&Molecular Engineering.
文摘Soft self-healing materials are promising candidates for flexible electronic devices due to their excep-tional compatibility,extensibility,and self-restorability.Generally,these materials suffer from low tensile strength and susceptibility to fracture because of the restricted microstructure design.Herein,we pro-pose a hydrothermal-freeze-thaw method to construct high-strength self-healing hydrogels with even in-terconnected networks and distinctive wrinkled surfaces.The integration of the wrinkled outer surface with the three-dimensional internal network confers the self-healing hydrogel with enhanced mechan-ical strength.This hydrogel achieves a tensile strength of 223 kPa,a breaking elongation of 442%,an adhesion strength of 57.6 kPa,and an adhesion energy of 237.2 J m-2.Meanwhile,the hydrogel demon-strates impressive self-repair capability(repair efficiency:93%).Moreover,the density functional theory(DFT)calculations are used to substantiate the stable existence of hydrogen bonding between the PPPBG hydrogel and water molecules which ensures the durability of the PPPBG hydrogel for long-term applica-tion.The measurements demonstrate that this multifunctional hydrogel possesses the requisite sensitivity and durability to serve as a strain sensor,which monitors a spectrum of motion signals including subtle vocalizations,pronounced facial expressions,and limb articulations.This work presents a viable strategy for healthcare monitoring,soft robotics,and interactive electronic skins.
基金supported by the National Natural Science Foundation of China(Nos.52325302 and 52173012)Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering(No.2022SZ-FR005)。
文摘Achieving continuous motions typically requires dynamic external stimuli for cyclic deformation,or crafted geometries with intricate modules to form a self-regulated feedback loop upon static stimulation.It is still a grand challenge to realize self-sustained motion in soft robots subject to unchanging environment,without complex geometry or a control module.In this work,we report soft robots based on an anisotropic cylindrical hydrogel showing self-regulated,continuous rolling motions under constant light irradiation.The robots are animated by mirror-symmetry-breaking induced by photothermal strain gradient.The self-sustained motion is attributed to the fast and reversible deformation of the gel and the autonomous refresh of the irradiated region during the rolling motion.The hydrogel robots can reach a rolling speed of 1.27 mm·s^(-1)on a horizonal surface and even climb a ramp of 18°at a speed of 0.57 mm·s^(-1)in an aqueous environment.Furthermore,the hydrogel robots can overcome an obstacle,with rolling direction controllable through irradiation angle of the light and local irradiation on selective regions.This work suggests a facile strategy to develop hydrogel robots and may provide unforeseen inspirations for the design of self-regulated soft robots by using other intelligent materials.
基金financially supported by the National Natural Science Foundation of China(No.22305033 received by Z.Y.L.,No.52161135102 received by P.Y.W.)the Fundamental Research Funds for the Central Universities(No.2232024A-05 received by Z.Y.L.)。
文摘Smart actuators and wearable and implantable devices have attracted much attention in healthcare and environmental sensing.Flexible electronic and ionic materials are the two main approaches used to construct these devices.Among them,hydrogel-based ionic materials offer unique advantages,such as biocompatibility and adaptable mechanical properties.However,ionic hydrogels encounter challenges in achieving wirelessly powered and noncontact sensing.To address this,we introduce MXene nanosheets to construct ionotronic hydrogels.Leveraging the rich surface charges and electronic conductivity of MXene nanosheets,ionotronic hydrogels can harvest vibrational and electromagnetic waves as electrical energy and enable noncontact sensing.Under ultrasound,it can continuously generate voltages up to 85 V and light up lightemitting diodes,promising wireless charging of implanted devices.In addition,it achieves an absorption coefficient of 0.2 for 915 MHz electromagnetic waves,enabling noncontact sensing through radio frequency identification.Notably,the physically crosslinked network of the MXenebased hydrogels maintained structural and performance stability under ultrasonic stimulation and exhibited self-healing properties.Even when cut into two halves,the self-healing hydrogel fully regenerates its original performance.This study provides insight into the development of ionotronic hydrogels for wirelessly powered and noncontact sensing in smart actuators and wearable and implantable applications.
基金supported by the Postdoctoral Fellowship Program of CPSF(Grant No.GZB20240607)the Postdoctoral Program of Shaanxi Province(Grant No.25010103232)。
文摘When a cracked hydrogel sample immersed in water is stretched,a swelling zone near the crack tip emerges.Within the swelling zone,water diffusion occurs and swells the hydrogel.Outside the swelling zone,water diffusion is negligible,and the material behaves like an incompressible elastomer.Since water diffusion is a time-dependent process,the size of the swelling zone changes with time.As time evolves,the size of the swelling zone grows until to the size of the hydrogel sample.There exists a competition between the size of the swelling zone and the size of the hydrogel sample,which results in complex rate-dependent fracture behavior of hydrogel.In this article,the competition effect is studied theoretically and numerically.We find that the hydrogel undergoes three stages gradually:small-scale swelling,large-scale swelling,and equilibrium as the size of the swelling zone approaches the size of the hydrogel sample.In the stage of small-scale swelling,the first invariant of stretch at the notch tip I1notch increases with the decrease of the stretch rate.In the stage of large-scale swelling,I1notch increases first and then decreases with the decrease of stretch rate.In the stage of equilibrium,the effect of water diffusion is negligible,and I1notch is independent of stretch rate.This work reveals the connection between the stretch rate,the size of the swelling zone,and the crack tip quantity I1notch,which is used to establish the fracture criterion and predict rate-dependent fracture of hydrogel.Particularly,the previous works on different trends of rate-dependent behavior of hydrogel can be unified in this work,when both small-scale swelling and large-scale swelling are considered.
基金supported by Singapore MOE Tier-2 Award MOE-T2EP50123-0015.
文摘The integration of 3D-printed hydrogels in soft robotics enables the creation of flexible,adaptable,and biocompatible systems.Hydrogels,with their high-water content and responsiveness to stimuli,are suitable for actuators,sensors,and robotic systems that require safe interaction and precise manipulation.Unlike traditional techniques,3D printing offers enhanced capabilities in tailoring structural complexity,resolution,and integrated functionality,enabling the direct fabrication of hydrogel systems with programmed mechanical and functional properties.In this perspective,we explore the evolving role of 3D-printed hydrogels in soft robotics,covering their material composition,fabrication techniques,and diverse applications.We highlight advancements in hydrogel-based actuators,sensors,and robots,emphasizing their ability to perform intricate motions.In addition,we discuss challenges like mechanical robustness,scalability,and integration as well as the potential of hydrogels in soft robotics and explore future directions for their development.
基金funded by the National Natural Science Foundation of China(grant No.82260596)the Natural Science Foundation of Jiangxi Province(grant No.20242BAB25506)+4 种基金the Science and Technology Program of Jiangxi Provincial Health and Family Planning Commission(grant No.202410246)the China Postdoctoral Science Foundation(grant No.2023M741523)he Science and Technology Program of Jiangxi Provincial Administration of Traditional Chinese Medicine(grant No.2024A0028)the Outstanding Youth Fund Program of Jiangxi Province(grant No.20252BAC220050)the Nanchang University Internal Funding Program Fund(grant No.2023efyB05).
文摘Traditional cancer therapies have limitations like poor efficacy on advanced tumors,healthy tissue damage,side effects,and drug resistance,creating an urgent need for new strategies.Hydrogels have good biocompatibility and controlled release,while extracellular vesicles(EVs)enable targeting and bioactive transport.This review systematically summarizes hydrogels and EVs,focusing on the construction of hydrogel-EV delivery system,key influencing factors,drug delivery mechanisms,and tumor therapy apps,clarifying their synergies.The system overcomes single-carrier flaws,construction methods/key factors affect performance,preclinical studies have confirmed efficacy in multiple therapies,but large-scale production and in vivo stability challenges remain,yet it promises to overcome the limits of traditional therapy for precision oncology.
基金support from Fonds de Recherche du Québec Santé(FRQS,grant no.281271)support from FRQS doctoral award #304367funding from CFI,Rheolution Inc.,and Investissement Québec.
文摘Xerostomia(dry mouth)is frequently experienced by patients treated with radiotherapy for head and neck cancers or with Sjögren’s syndrome,with no permanent cure existing for this debilitating condition.To this end,in vitro platforms are needed to test therapies directed at salivary(fluid-secreting)cells.However,since these are highly differentiated secretory cells,the maintenance of their differentiated state while expanding in numbers is challenging.In this study,the efficiency of three reversible thermo-ionically crosslinked gels:(1)alginate–gelatin(AG),(2)collagen-containing AG(AGC),and(3)hyaluronic acid-containing AG(AGHA),to recapitulate a native-like environment for human salivary gland(SG)cell expansion and 3D spheroid formation was compared.Although all gels were of mechanical properties comparable to human SG tissue(~11 kPa)and promoted the formation of 3D spheroids,AGHA gels produced larger(>100 cells/spheroid),viable(>93%),proliferative,and well-organized 3D SG spheroids while spatially and temporally maintaining the high expression of key SG proteins(aquaporin-5,NKCC1,ZO-1,α-amylase)for 14 days in culture.Moreover,the spheroids responded to agonist-induced stimulation by increasingα-amylase secretory granules.Here,we propose alternative lowcost,reproducible,and reversible AG-based 3D hydrogels that allow the facile and rapid retrieval of intact,highly viable 3D-SG spheroids.
基金the funding and generous support of the National Natural Science Foundation of China(52103263,52271249)the Key Project of International Science&Technology Cooperation of Shaanxi Province(2023-GHZD-09)+5 种基金the Key Project of Science Foundation of Education Department of Shaanxi Province(22JY011)the Key Project of Scientific Research and Development of Shaanxi Province(2023GXLH-070)the Qinchuangyuan"Scientist+Engineer"Team of Shaanxi Province(2023KXJ-069)the Key Research and Development Program of Shaanxi(2023-YBGY-488)the Sci-tech Innovation Team of Shaanxi Province(2024RS-CXTD-46)the Key Research and Development Program of Shaanxi Province(2020ZDLGY13-11).
文摘All-season thermal management with zero energy consumption and emissions is more crucial to global decarbonization over traditional energy-intensive cooling/heating systems.However,the static single thermal management for cooling or heating fails to self-regulate the temperature in dynamic seasonal temperature condition.Herein,inspired by the dual-temperature regulation function of the fur color changes on the backs and abdomens of penguins,a smart thermal management composite hydrogel(PNA@H-PM Gel)system was subtly created though an"on-demand"dual-layer structure design strategy.The PNA@H-PM Gel system features synchronous solar and thermal radiation modulation as well as tunable phase transition temperatures to meet the variable seasonal thermal requirements and energy-saving demands via self-adaptive radiative cooling and solar heating regulation.Furthermore,this system demonstrates superb modulations of both the solar reflectance(ΔR=0.74)and thermal emissivity(ΔE=0.52)in response to ambient temperature changes,highlighting efficient temperature regulation with average radiative cooling and solar heating effects of 9.6℃in summer and 6.1℃in winter,respectively.Moreover,compared to standard building baselines,the PNA@H-PM Gel presents a more substantial energy-saving cooling/heating potentials for energy-efficient buildings across various regions and climates.This novel solution,inspired by penguins in the real world,will offer a fresh approach for producing intelligent,energy-saving thermal management materials,and serve for temperature regulation under dynamic climate conditions and even throughout all seasons.
基金financially supported by the National Key Research and Development Program of China(2022YFE0138900)the National Natural Science Foundation of China(21972017)+1 种基金the Fundamental Research Funds for the Central Universities of Ministry of Education of China(D5000240188)the"Scientific and Technical Innovation Action Plan"Basic Research Field of Shanghai Science and Technology Committee(19JC1410500)。
文摘Traditional hydrogels are inevitably damaged during practical applications,resulting in a gradual deterioration of their functional efficacy.A primary strategy to address this issue involves developing hydrogels with inherent self-healing properties.In this study,we report the synthesis of self-healing polyacrylate hydrogels that integrate zwitterions,hydrophilic nano-silica and aluminum ions.Due to the synergistic effect of multiple hydrogen bonds,coordination bonds and electrostatic interactions,the tensile strength of the hydrogel is enhanced from 15.1 to 162.6 kPa.Moreover,the electrical resistance and tensile strength of the hydrogel can almost recover to its initial values after 20 min of healing at room temperature,exhibiting remarkable self-healing performance.Furthermore,the zwitterionic polyacrylate hydrogel serves as a wearable sensor with the capability of accurately response to the bending and stretching of human joints,exhibting a gauge factor of 1.87 under tensile strain ranging from 80% to 100%.Even after being freezed at-20℃ for 3 h,the zwitterionic polyacrylate hydrogel retains its exceptional writing performance.In conclusion,the hydrogels developed in this study demonstrate significant potential for wearable electronics applications.
基金supported by the National Natural Science Foundation of China(22071019,21872021 and 21671033).
文摘With several favorable properties,including flexibility,biocompatibility,and conductivity,conductive hydrogels are one of the most promising flexible sensing materials and are expected to be used in areas such as wearable devices,health monitoring,and electronic skin.However,water in hydrogels freezes at sub-zero temperatures,which greatly affects the performance of hydrogels at low temperatures.Therefore,it remains a challenge to prepare conductive hydrogels that can maintain their performance at low temperatures.In this work,we developed a series of polyoxometalate-based anti-freezing hydrogels with high conductivity by constructing a semi-interpenetrating network using polyacrylamide and sodium alginate,and then introducing H_(3)PW_(12)O_(40)(HPW)and glycerol into it via a facile soaking strategy.Among the obtained anti-freezing hydrogels,PSWG-50%hydrogel has the proton conductivity of 0.325 S·cm^(−1) at room temperature and can maintain high proton conductivity over a wide temperature range from−20 to 65℃.Based on these advantages,PSWG-50%hydrogel has been used in flexible sensors to monitor human movement,such as limb bending.Whether in mild or cold environments,PSWG-50%hydrogel shows great potential in the field of flexible sensor.
基金supported by the Smart Medicine and Engineering Interdisciplinary Innovation Project of Ningbo University(Grant No.ZHYG003)the National Natural Science Foundation of China(Grant Nos.12372165 and 12202387)+1 种基金the Ningbo Top Medical and Health Research Program(Grant No.2022020203)the Zhejiang Engineering Research Center of Innovative technologies and diagnostic and thera-peutic equipment for urinary system diseases.
文摘Enhancing gelatin methacryloyl(GelMA)hydrogel mechanics without compromising biocompatibility remains challenging,as conventional chemical crosslinking often disrupts degradation behavior.A cooling-induced entan-glement strategy effectively improves mechanical performance while preserving biological properties;however,its underlying mechanisms remain unclear.This study demonstrates that extended cooling durations significantly enhance the mechanical properties of GelMA hydrogels.Microstructural analyses reveal cooling-induced forma-tion of compact polymer networks with reduced mesh sizes.Molecular dynamics(MD)simulations confirm that the cooling process promotes topological entanglements that govern mechanical reinforcement.Guided by these insights,we propose a theoretical model to predict the stress responses of GelMA hydrogels under various cooling durations,establishing quantitative correlations between entanglement mechanisms and mechanical outcomes.This study provides a fundamental understanding of the interplay between cooling conditions,microstructure,and mechanical performance,offering a robust framework for designing GelMA hydrogels with optimized me-chanical properties for advanced biomedical applications.
基金financially supported by the Young Scientists Fund of National Natural Science Foundation of China(Grant No.52303106)Research Grants Council of Hong Kong SAR(16200720)+3 种基金Environment and Conservation Fund of Hong Kong SAR(Project No.21/2022)Research Institute of Sports Science and Technology(Project No.P0043535)Research Institute of Advanced Manufacturing(Project No.P0046125)the start-up fund for new recruits of Poly U(Project No.P0038855 and P0038858)。
文摘Hygroscopic hydrogel is a promising evaporativecooling material for high-power passive daytime cooling with water self-regeneration.However,undesired solar and environmental heating makes it a challenge to maintain sub-ambient daytime cooling.While different strategies have been developed to mitigate heat gains,they inevitably sacrifice the evaporation and water regeneration due to highly coupled thermal and vapor transport.Here,an anisotropic synergistically performed insulation-radiation-evaporation(ASPIRE)cooler is developed by leveraging a dual-alignment structure both internal and external to the hydrogel for coordinated thermal and water transport.The ASPIRE cooler achieves an impressive average sub-ambient cooling temperature of~8.2℃ and a remarkable peak cooling power of 311 W m^(-2)under direct sunlight.Further examining the cooling mechanism reveals that the ASPIRE cooler reduces the solar and environmental heat gains without comprising the evaporation.Moreover,self-sustained multi-day cooling is possible with water self-regeneration at night under both clear and cloudy days.The synergistic design provides new insights toward high-power,sustainable,and all-weather passive cooling applications.
