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
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
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
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
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
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
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
Hydrogels possess significant potential for the development of multifunctional soft materials in smart sensors and wearable devices,attributed to their distinctive properties of softness,conductivity,and biocompatibil...Hydrogels possess significant potential for the development of multifunctional soft materials in smart sensors and wearable devices,attributed to their distinctive properties of softness,conductivity,and biocompatibility.Nevertheless,their widespread application is frequently limited by inadequate mechanical strength and strain capacity.This study introduces a meticulously engineered hydrogel system,LM/SA/P(AAM-co-BMA),which integrates eutectic gallium-indium alloy(EGaIn)as both a polymerization initiator and a flexible filler.The resultant hydrogel demonstrates remarkable tensile strain capabilities of up to 2800% and a tensile strength of 2.3 MPa,achieved through a synergistic interplay of ionic coordination,hydrogen bonding,and physical polymer interactions.Furthermore,the hydrogel exhibits outstanding biocompatibility,recyclability,and stable long-term storage,rendering it an ideal candidate for the continuous monitoring of high-intensity physical activities.展开更多
Ideal conductive hydrogels with their mechanical ductility,high conductivity and self-adhesion are es-sential for potential promising application as fascinating sensing materials in wearable electronic devices.Unfortu...Ideal conductive hydrogels with their mechanical ductility,high conductivity and self-adhesion are es-sential for potential promising application as fascinating sensing materials in wearable electronic devices.Unfortunately,due to the inevitable performance degeneration stemming from swelling features in aque-ous conditions,the applicability of hydrogel-based sensors is greatly reduced in aquatic environments.Herein,an amphibious hydrogel with mechanical ductile,self-adhesive,anti-freezing,and high strain sensitivity underwater is developed.The hydrogel produces a rapid self-gelation behavior at ambient conditions(several minutes)through a catechol redox reaction based on lignocellulosic nanofibril-Ag^(+).The tough polymer network by the virtue of strong hydrogen bonding and nano-reinforcement enables the resultant hydrogel with improved mechanical performance.Meanwhile,outstanding properties in-cluding high conductivity(2.12 S/m),strain sensing ability(maximum GF:3.98),good water resistance(equilibrium swelling ratio of 1.2%after 30 d)as well as other solvents,air/underwater adhesiveness,and anti-freezing performance can be obtained simultaneously.A sensor based on such hydrogel can be conveniently conformed and attached to the human limbs for achieving non-invasive,high stability and continuous underwater communications and habits tracking of marine.Briefly,this work provides an innovative route to develop multifunctional integration hydrogel-based flexible devices for information transmission in marine environments.展开更多
The primary objective of Cartilage Tissue Engineering(CTE)involves repairing or rebuilding impaired cartilage in an effort to restore joint functionality and enhance patients'quality of life.In this field,research...The primary objective of Cartilage Tissue Engineering(CTE)involves repairing or rebuilding impaired cartilage in an effort to restore joint functionality and enhance patients'quality of life.In this field,researchers are constantly exploring new materials and technologies to address the challenges posed by cartilage damage.Biomimetic hydrogels present several distinct advantages in articular cartilage repair when compared to conventional treatment methods like minimally invasive surgery,joint replacement,and drug therapies.These hydrogels effectively mimic the mechanical characteristics of natural cartilage while also promoting cell adhesion,proliferation,and differentiation through the inclusion of bioactive factors.This results in the creation of high-performance biomaterials,positioning them as a particularly promising therapeutic option.Recently,researchers have drawn inspiration from the intricate structures found in soft tissues to develop various types of biomimetic hydrogels.These innovative hydrogels find applications across various fields,such as biomedicine,tissue engineering,and flexible electronics.In tissue engineering,these materials serve as optimal scaffolds for cartilage regeneration and aid in restoring tissue function.Nevertheless,creating and manufacturing biomimetic hydrogels with complex designs,strong mechanical properties,and multifunctionality poses significant challenges.This paper reviews existing studies on natural and synthetic matrices for biomimetic hydrogels,explores the similarities between these hydrogels and natural cartilage,examines their biological and physical characteristics,discusses their advantages and limitations,and suggests future research avenues.展开更多
Granular composite(GC)hydrogels have attracted considerable interest in biomedical applications due to their versatile printability and exceptional mechanical properties.However,the lack of comprehensive design guidel...Granular composite(GC)hydrogels have attracted considerable interest in biomedical applications due to their versatile printability and exceptional mechanical properties.However,the lack of comprehensive design guidelines has limited their optimal engineering,as the factors influencing their mechanical performance and printability remain largely unexamined.In this study,we developed GC hydrogels by integrating microgels with interstitial matrices of photocrosslinkable gelatin methacrylate(GelMA).We utilized confocal microscopy and nanoindentation analyses to investigate the spatial distribution and mechanical behavior of these hydrogels.Our findings indicate that the mechanical and rheological properties of GC hydrogels can be precisely tailored by adjusting the volume fraction and size of the microgels.Furthermore,hydrogen bonds were identified as significant contributors to compressive performance,although they had minimal effect on cyclic mechanical behavior.Compared to bulk GelMA hydrogels,GC hydrogels demonstrated enhanced printability and remarkable superelasticity.As a proof of concept,we illustrated their dual printability in embedded printing to create prosthetic liver models for preoperative planning.This study provides valuable insights into the design and optimization of GC hydrogels for advanced biomedical applications.展开更多
Wound healing in diabetic patients presents significant challenges due to heightened risks of bacterial infection,elevated glucose levels,and insufficient angiogenesis.Nanozymes are widely employed for wound healing,b...Wound healing in diabetic patients presents significant challenges due to heightened risks of bacterial infection,elevated glucose levels,and insufficient angiogenesis.Nanozymes are widely employed for wound healing,but most current nanozyme systems exhibit only moderate activity limited by incompatible reaction microenvironments including p H and hydrogen peroxide(H_(2)O_(2))concentration.Herein,a glucoseactivated nanozyme hydrogel was developed using bovine serum albumin(BSA)-modified gold nanoparticles(Au NPs)attached to a two-dimensional(2D)metal-organic framework(MOF)(Cu-TCPP(Fe)@Au@BSA)by an in situ growth method.The Au NPs function as a glucose oxidase(GOx)-like enzyme,converting glucose to gluconic acid and H_(2)O_(2),triggering the peroxidase(POD)-like activity of Cu-TCPP(Fe)to produce hydroxyl radicals(·OH),effectively eliminating bacteria.Additionally,the modification of BSA reduces the Au NP size,enhancing enzyme activity.Both in vitro and in vivo tests demonstrate that this nanozyme hydrogel can be activated by the microenvironment to lower blood glucose,eliminate bacterial infections,and promote epithelial formation and collagen deposition,thus accelerating diabetic wound healing effectively.The multifunctional nanozyme hydrogel dressing developed in this study presents a promising therapeutic approach to enhance diabetic wound healing.展开更多
Conductive hydrogels have garnered widespread attention as a versatile class of flexible electronics.Despite considerable advancements,current methodologies struggle to reconcile the fundamental trade-off between high...Conductive hydrogels have garnered widespread attention as a versatile class of flexible electronics.Despite considerable advancements,current methodologies struggle to reconcile the fundamental trade-off between high conductivity and effective absorption-dominated electromagnetic interference(EMI)shielding,as dictated by classical impedance matching theory.This study addresses these limitations by introducing a novel synthesis of aramid nanofiber/MXene-reinforced polyelectrolyte hydrogels.Leveraging the unique properties of polyelectrolytes,this innovative approach enhances ionic conductivity and exploits the hydration effect of hydrophilic polar groups to induce the formation of intermediate water.This critical innovation facilitates polarization relaxation and rearrangement in response to electromagnetic fields,thereby significantly enhancing the EMI shielding effectiveness of hydrogels.The electromagnetic wave attenuation capacity of these hydrogels was thoroughly evaluated across both X-band and terahertz band frequencies,with further investigation into the impact of varying water content states-hydrated,dried,and frozen-on their electromagnetic properties.Moreover,the hydrogels exhibited promising capabilities beyond mere EMI shielding;they also served effectively as strain sensors for monitoring human motions,indicating their potential applicability in wearable electronics.This work provides a new approach to designing multifunctional hydrogels,advancing the integration of flexible,multifunctional materials in modern electronics,with potential applications in both EMI shielding and wearable technology.展开更多
Hydrogels, as a novel class of biomaterials, exhibit broad application prospects and are widely used in tissue engineering. In the field of periodontology within dental medicine, hydrogels can be employed for periodon...Hydrogels, as a novel class of biomaterials, exhibit broad application prospects and are widely used in tissue engineering. In the field of periodontology within dental medicine, hydrogels can be employed for periodontal tissue regeneration to repair the damage caused by periodontitis. At present, various hydrogels have been developed to control periodontal inflammation and repair periodontal tissues. This article, based on domestic and international literature, provides a brief review of hydrogels used in periodontal tissue regeneration.展开更多
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.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 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 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.
基金supported primarily by National Key Research and Development Program of China(2020YFA0710303)The authors thank the support from Natural Science Foundation of Fujian Province(2024J01258)Scientific Research Foundation of Fuzhou University(510936).
文摘Hydrogels possess significant potential for the development of multifunctional soft materials in smart sensors and wearable devices,attributed to their distinctive properties of softness,conductivity,and biocompatibility.Nevertheless,their widespread application is frequently limited by inadequate mechanical strength and strain capacity.This study introduces a meticulously engineered hydrogel system,LM/SA/P(AAM-co-BMA),which integrates eutectic gallium-indium alloy(EGaIn)as both a polymerization initiator and a flexible filler.The resultant hydrogel demonstrates remarkable tensile strain capabilities of up to 2800% and a tensile strength of 2.3 MPa,achieved through a synergistic interplay of ionic coordination,hydrogen bonding,and physical polymer interactions.Furthermore,the hydrogel exhibits outstanding biocompatibility,recyclability,and stable long-term storage,rendering it an ideal candidate for the continuous monitoring of high-intensity physical activities.
基金supported by the National Natural Science Foundation of China(No.52203148)the Zhejiang A&F University Scientific Research Training Program for Undergraduates(Nos.2024kx0026 and 2024kx0027)the Research Foundation of Talented Scholars of Zhejiang A&F University(No.2020FR070)。
文摘Ideal conductive hydrogels with their mechanical ductility,high conductivity and self-adhesion are es-sential for potential promising application as fascinating sensing materials in wearable electronic devices.Unfortunately,due to the inevitable performance degeneration stemming from swelling features in aque-ous conditions,the applicability of hydrogel-based sensors is greatly reduced in aquatic environments.Herein,an amphibious hydrogel with mechanical ductile,self-adhesive,anti-freezing,and high strain sensitivity underwater is developed.The hydrogel produces a rapid self-gelation behavior at ambient conditions(several minutes)through a catechol redox reaction based on lignocellulosic nanofibril-Ag^(+).The tough polymer network by the virtue of strong hydrogen bonding and nano-reinforcement enables the resultant hydrogel with improved mechanical performance.Meanwhile,outstanding properties in-cluding high conductivity(2.12 S/m),strain sensing ability(maximum GF:3.98),good water resistance(equilibrium swelling ratio of 1.2%after 30 d)as well as other solvents,air/underwater adhesiveness,and anti-freezing performance can be obtained simultaneously.A sensor based on such hydrogel can be conveniently conformed and attached to the human limbs for achieving non-invasive,high stability and continuous underwater communications and habits tracking of marine.Briefly,this work provides an innovative route to develop multifunctional integration hydrogel-based flexible devices for information transmission in marine environments.
基金supported by the Shandong Provincial Natural Science Foundation(for the preparation of bionic scaffolds for bone and cartilage repair and their osteogenic wear resistance study)(ZR2022ME086).
文摘The primary objective of Cartilage Tissue Engineering(CTE)involves repairing or rebuilding impaired cartilage in an effort to restore joint functionality and enhance patients'quality of life.In this field,researchers are constantly exploring new materials and technologies to address the challenges posed by cartilage damage.Biomimetic hydrogels present several distinct advantages in articular cartilage repair when compared to conventional treatment methods like minimally invasive surgery,joint replacement,and drug therapies.These hydrogels effectively mimic the mechanical characteristics of natural cartilage while also promoting cell adhesion,proliferation,and differentiation through the inclusion of bioactive factors.This results in the creation of high-performance biomaterials,positioning them as a particularly promising therapeutic option.Recently,researchers have drawn inspiration from the intricate structures found in soft tissues to develop various types of biomimetic hydrogels.These innovative hydrogels find applications across various fields,such as biomedicine,tissue engineering,and flexible electronics.In tissue engineering,these materials serve as optimal scaffolds for cartilage regeneration and aid in restoring tissue function.Nevertheless,creating and manufacturing biomimetic hydrogels with complex designs,strong mechanical properties,and multifunctionality poses significant challenges.This paper reviews existing studies on natural and synthetic matrices for biomimetic hydrogels,explores the similarities between these hydrogels and natural cartilage,examines their biological and physical characteristics,discusses their advantages and limitations,and suggests future research avenues.
基金support from the National Natural Science Foundation of China(Nos.U21A20394 and 52305314)the Beijing Natural Science Foundation(Nos.7252285 and L246001)the National Key Research and Development Program of China(No.2023YFB4605800)。
文摘Granular composite(GC)hydrogels have attracted considerable interest in biomedical applications due to their versatile printability and exceptional mechanical properties.However,the lack of comprehensive design guidelines has limited their optimal engineering,as the factors influencing their mechanical performance and printability remain largely unexamined.In this study,we developed GC hydrogels by integrating microgels with interstitial matrices of photocrosslinkable gelatin methacrylate(GelMA).We utilized confocal microscopy and nanoindentation analyses to investigate the spatial distribution and mechanical behavior of these hydrogels.Our findings indicate that the mechanical and rheological properties of GC hydrogels can be precisely tailored by adjusting the volume fraction and size of the microgels.Furthermore,hydrogen bonds were identified as significant contributors to compressive performance,although they had minimal effect on cyclic mechanical behavior.Compared to bulk GelMA hydrogels,GC hydrogels demonstrated enhanced printability and remarkable superelasticity.As a proof of concept,we illustrated their dual printability in embedded printing to create prosthetic liver models for preoperative planning.This study provides valuable insights into the design and optimization of GC hydrogels for advanced biomedical applications.
基金supported by the National Natural Science Foundation of China Project(No.22208321)the China Postdoctoral Science Foundation Project(No.2022M720130)+1 种基金the Key Scientific Research Project of Henan Province High Education Institutions(No.24A350018)the Natural Science Foundation of Henan Province-Outstanding Youth Foundation(No.232300421058)。
文摘Wound healing in diabetic patients presents significant challenges due to heightened risks of bacterial infection,elevated glucose levels,and insufficient angiogenesis.Nanozymes are widely employed for wound healing,but most current nanozyme systems exhibit only moderate activity limited by incompatible reaction microenvironments including p H and hydrogen peroxide(H_(2)O_(2))concentration.Herein,a glucoseactivated nanozyme hydrogel was developed using bovine serum albumin(BSA)-modified gold nanoparticles(Au NPs)attached to a two-dimensional(2D)metal-organic framework(MOF)(Cu-TCPP(Fe)@Au@BSA)by an in situ growth method.The Au NPs function as a glucose oxidase(GOx)-like enzyme,converting glucose to gluconic acid and H_(2)O_(2),triggering the peroxidase(POD)-like activity of Cu-TCPP(Fe)to produce hydroxyl radicals(·OH),effectively eliminating bacteria.Additionally,the modification of BSA reduces the Au NP size,enhancing enzyme activity.Both in vitro and in vivo tests demonstrate that this nanozyme hydrogel can be activated by the microenvironment to lower blood glucose,eliminate bacterial infections,and promote epithelial formation and collagen deposition,thus accelerating diabetic wound healing effectively.The multifunctional nanozyme hydrogel dressing developed in this study presents a promising therapeutic approach to enhance diabetic wound healing.
基金supported by the National Natural Science Foundation of China(52375204)Shaanxi Provincial Science and Technology Innovation Team(2024RS-CXTD-63)+4 种基金Xianyang 2023 Key Research and Development Plan(L2023-ZDYF-QYCX-009)the Fundamental Research Funds for the Central Universities(D5000230356)2024“Double First-Class University”Construction Special Fund Project(0604024GH0201332,0604024SH0201332)Zhiyuan Laboratory(NO.ZYL2024007)Horizon Europe Framework Programme(101086071-CUPOLA).
文摘Conductive hydrogels have garnered widespread attention as a versatile class of flexible electronics.Despite considerable advancements,current methodologies struggle to reconcile the fundamental trade-off between high conductivity and effective absorption-dominated electromagnetic interference(EMI)shielding,as dictated by classical impedance matching theory.This study addresses these limitations by introducing a novel synthesis of aramid nanofiber/MXene-reinforced polyelectrolyte hydrogels.Leveraging the unique properties of polyelectrolytes,this innovative approach enhances ionic conductivity and exploits the hydration effect of hydrophilic polar groups to induce the formation of intermediate water.This critical innovation facilitates polarization relaxation and rearrangement in response to electromagnetic fields,thereby significantly enhancing the EMI shielding effectiveness of hydrogels.The electromagnetic wave attenuation capacity of these hydrogels was thoroughly evaluated across both X-band and terahertz band frequencies,with further investigation into the impact of varying water content states-hydrated,dried,and frozen-on their electromagnetic properties.Moreover,the hydrogels exhibited promising capabilities beyond mere EMI shielding;they also served effectively as strain sensors for monitoring human motions,indicating their potential applicability in wearable electronics.This work provides a new approach to designing multifunctional hydrogels,advancing the integration of flexible,multifunctional materials in modern electronics,with potential applications in both EMI shielding and wearable technology.
文摘Hydrogels, as a novel class of biomaterials, exhibit broad application prospects and are widely used in tissue engineering. In the field of periodontology within dental medicine, hydrogels can be employed for periodontal tissue regeneration to repair the damage caused by periodontitis. At present, various hydrogels have been developed to control periodontal inflammation and repair periodontal tissues. This article, based on domestic and international literature, provides a brief review of hydrogels used in periodontal tissue regeneration.
