AIM:To investigate the biocompatibility and bacterial adhesion properties of light responsive materials(LRM)and analyze the feasibility and biosafety of employing LRM in the preparation of accommodative intraocular le...AIM:To investigate the biocompatibility and bacterial adhesion properties of light responsive materials(LRM)and analyze the feasibility and biosafety of employing LRM in the preparation of accommodative intraocular lenses(AIOLs).METHODS:Employing fundamental experimental research techniques,LRM with human lens epithelial cells(hLECs)and human retinal pigment epithelium cells(ARPE-19 cells)were co-cultured.Commercially available intraocular lenses(IOLs)were used as controls to perform cell counting kit-8(CCK-8),cell staining under varying light intensities,cell adhesion and bacterial adhesion experiments.RESULTS:LRM exhibited a stronger inhibitory effect on the proliferation of ARPE19 cells than commercially available IOLs when co-cultured with the undiluted extract for 96h(P<0.05).Under other culturing conditions,the effects on the proliferation of hLECs and ARPE-19 cells were not significantly different between the two materials.Under the influence of light irradiation at intensities of 200 and 300 mW/cm^(2),LRM demonstrated a markedly higher inhibitory effect on the survival of hLECs compared to commercially available IOLs(P<0.0001).They also showed a stronger suppressive effect on the survival rate of ARPE-19 cells,with significant differences observed at 200 mW/cm^(2)(P<0.001)and extremely significant differences at 300 mW/cm^(2)(P<0.0001).Additionally,compared to commercially available IOLs,LRM had a higher number of cells adhering to their surface(P<0.05),as well as a significantly greater number of adherent bacterium(P<0.0001).CONCLUSION:LRM,characterized by their excellent non-contact tunable deformability and low cytotoxicity to ocular tissues,show considerable potential for use in the fabrication of AIOLs.These materials demonstrate strong cell adhesion;however,during photothermal conversion processes involving shape deformation under various light intensities,the resultant temperature rise may harm surrounding cells.These factors suggest that while the material plays a positive role in reducing the incidence of posterior capsule opacification(PCO),it also poses potential risks for retinal damage.Additionally,the strong bacterial adhesion of these materials indicates an increased risk of endophthalmitis.展开更多
Soft actuators and stimuli responsive materials are highlighted in the research field for their enormous potential in transit tasks,sensing,and biomedical devices,particularly the magnetic responsive soft actu-ators d...Soft actuators and stimuli responsive materials are highlighted in the research field for their enormous potential in transit tasks,sensing,and biomedical devices,particularly the magnetic responsive soft actu-ators driven by magnetic force remotely.Nevertheless,the further study of magnetic responsive actuators with complex three-dimensional geometries and multiple functions is still limited by uncomplicated de-sign and flexible locomotion.This work provides a novel scheme integrating the origami method and modular designs,which defines the inner properties of magnetic material,extending the functions of magnetic responsive actuators with various modules.The directions of the inner magnetic moments can be programmed and the deformation degrees can be regulated by this approach,which promotes the fabrication of complicated soft actuators with multiple functions by integrating with modular designs.Especially,a movable actuator with various sensing modulus is designed by the origami method,which can perform the sensing application to external ultra-violet(UV),heat,and pH stimuli.Moreover,a mi-croneedle modular actuator which can be controlled wirelessly by a magnetic field was demonstrated for the potential application in the biomedical field.This proposed scheme for engineering magnetic respon-sive material with modular designs has shown great potential to improve the feasibility,versatility,and multiple functionalities of soft actuators.展开更多
Multi-stimuli responsive materials controlled and coupled by two or more channels have a broad range of applications in the field of switches,memories,and molecular machines.The exploration of the material is currentl...Multi-stimuli responsive materials controlled and coupled by two or more channels have a broad range of applications in the field of switches,memories,and molecular machines.The exploration of the material is currently focused on the pure organic system,which limits the development o such materials greatly.In this work,we present a new chiral organic-inorganic hybrid salt,(R-3hydroxypyrrolidinium)_(2)[Fe(CN)_(5)(NO)](1),which exhibits rare multi-stimuli responsive behaviors in ther mal,mechanical and optical channels.In detail,1 undergoes a C2-P2_(1)22_(1) phase transition deriving from the thermal motion of organic cations with the increase of temperature,but the reverse transition can only be induced by mechanical pressure.Moreover,polycrystalline hybrid salt showed photo-responsive performance,i.e.,the ground-state N-bound nitrosyl ligand adopts two configurations in excited state caused by light in 532 nm irradiation,accompanying with a photo-induced structural transformation o the anionic framework.Namely,the thermal motion characteristics of organic cations,the photoresponse characteristics of anionic inorganic skeleton and the pressure characteristics from hydrogen bonds are si multaneously integrated in 1.This unprecedented coupling mechanism of multi-stimuli responses make1 a potential candidate for future multichannel data storage applications.展开更多
How the wave propagation analysis plays a key role in the studies of dynamic response of materials at high strain rates is analyzed. For the wave propagation technique, the followings are important: the loading and un...How the wave propagation analysis plays a key role in the studies of dynamic response of materials at high strain rates is analyzed. For the wave propagation technique, the followings are important: the loading and unloading constitutive relation presumed, the positions of the sensors embedded, the interactions between loading waves and unloading waves. For the split Hopkinson pressure bar (SHPB) technique, the assumption of one-dimensional stress wave propagation and the assumption of stress uniformity along the specimen should be satisfied. When the larger diameter bars are employed, the wave dispersion effects should be considered, including the high frequency oscillations, non-uniform stress distribution across the bar section, increase of rise time, and amplitude attenuation. The stress uniformity along the specimen is influenced by the reflection times in specimen, the wave impedance ratio of the specimen and the bar, and the waveform.展开更多
Realizing the accurate characterization for the dynamic damage process is a great challenge. Here we carry out testing simultaneously for dynamic monitoring and acoustic emission （AE） statistical analysis towards fi...Realizing the accurate characterization for the dynamic damage process is a great challenge. Here we carry out testing simultaneously for dynamic monitoring and acoustic emission （AE） statistical analysis towards fiber composites under mode-Ⅱ delamination damage. The load curve, AE relative energy, amplitude distribution, and amplitude spectrum are obtained and the delamination damage mechanism of the composites is investigated by the microscopic observation of a fractured specimen. The results show that the micro-damage accumulation around the crack tip region has a great effect on the evolutionary process of delamination. AE characteristics and amplitude spectrum represent the damage and the physical mechanism originating from the hierarchical microstructure. Our finding provides a novel aud feasible strategy to simultaneously evaluate the dynamic response and micro-damage mechanism for fiber composites.展开更多
Stimulus re s ponsive materials can provide a variety of desirable properties in one equipment unit,such as optoelectronic devices,data communications,actuators,memories,sensors and capacitors.However,it remains a lar...Stimulus re s ponsive materials can provide a variety of desirable properties in one equipment unit,such as optoelectronic devices,data communications,actuators,memories,sensors and capacitors.However,it remains a large challenge to design such stimulus responsive materials,especially functional materials having both dielectric switch and second harmonic generation(SHG).Here,a new stimuli-responsive switchable material [(CH_(3))_(3)N(CH_(2))_(2)Cl]_(2)]Mn(SCN)_(4)(H_(2)O)_(2)] was discovered as a potential secondharmonic generation(SHG) dielectric switch.It is worth noting that it has SHG characteristics before and after undergoing reversible high-temperature phase transitions.In this work,we successfully refined the tetramethylammonium cation to obtain a quasi-spherical cation,which is tetramethylchloroethylamine(TMCEM) cation.By substituting H with a halogen,the increased steric hindrance of the molecular makes energy barrier increased,resulting in the reversible high-temperature phase transition.At the same time,the interactions of quasi-spherical cations and [Mn(SCN)_(4)(H_(2)O)_(2)]^(2-) anions affect a noncentrosymmetric structure to induce the SHG effect.These findings provide a new approach to design novel functional switch materials.展开更多
Constructingeco-friendlystimuli-responsivephosphorescence materials remains challenging and fascinating.Herein,we use natural cellulose as the rawmaterial to prepare pH-responsive room-temperature phosphorescent(RTP)m...Constructingeco-friendlystimuli-responsivephosphorescence materials remains challenging and fascinating.Herein,we use natural cellulose as the rawmaterial to prepare pH-responsive room-temperature phosphorescent(RTP)materials with excellent biodegradability by introducing anionic structures.The introduction of a phenylcarboxylate substituent not only promotes intersystem crossing but also brings about electrostatic-attractive and strong hydrogenbonding interactions,which enhance the intermolecular chain interactions.Therefore,the obtained anionic cellulose derivatives containing phenylcarboxylate groups exhibit ultra-long RTP.More intriguingly,these cellulose-based phosphorescent materials have a distinctive pH-responsive behavior.Under acidic conditions,the carboxylate is converted into the carboxylic acid,resulting in phosphorescence quenching.This process is reversible.Moreover,the obtained cellulosebased phosphorescent materials have excellent processability and can be easily processed into various material forms,such as film,coating,and pattern,by using eco-friendly aqueous solution processing strategies.Such proof-of-concept biomass-based phosphorescent materials with unique pH-responsive behavior and excellent processability have a huge potential in information encryption,advanced anti-counterfeiting,and food monitoring.展开更多
Deuteration of hydrogen-bonded phase transition crystals can increase the transition temperatures due to the isotope effect. But rare examples show the opposite trend that originates from the structural changes of the...Deuteration of hydrogen-bonded phase transition crystals can increase the transition temperatures due to the isotope effect. But rare examples show the opposite trend that originates from the structural changes of the hydrogen bond, known as the geometric H/D isotope effect. Herein, we report an organic crystal, diethylammonium hydrogen 1,4-terephthalate, exhibits a reversible structural phase transition and dielectric switching. Structural study shows the cations reside in channels formed by one-dimensional hydrogen-bonded anionic chains and undergo an order-disorder transition at around 206 K. The deuterated counterpart shows an elongation of the O…O hydrogen bond by about 0.005 A. This geometric isotope effect releases the internal pressure of the anionic host on the cation vips and results in a downward shift of the phase transition temperature by 10 K.展开更多
The tribological properties of newly developed friction material were evaluated by statistical analysis of the major affecting factors.The material for investigation was non-metallic friction material synergistically ...The tribological properties of newly developed friction material were evaluated by statistical analysis of the major affecting factors.The material for investigation was non-metallic friction material synergistically reinforced with aramid fibre and CaSO 4 whisker,which was developed for hoisting applications in coal mine.The response surface method（RSM）was employed to analyze the material performances affected by the independent and interactive effect of the factors under the normal working condition and severe working condition,respectively.Results showed that under the normal working condition,the newly developed material exhibited stable tribological properties which were insensitive to the test conditions.While under the severe working condition,the sliding velocity was the most dominant factor affecting the friction coefficient.Additionally,compared to the commercially available material,the modified material showed superior wear resistance and thermal stability.展开更多
In this paper,we consider the dynamic response of a pre-stressed sandwich plate-strip with a piezoelectric core and elastic layers under the action of a time-harmonic force resting on a rigid foundation.The investigat...In this paper,we consider the dynamic response of a pre-stressed sandwich plate-strip with a piezoelectric core and elastic layers under the action of a time-harmonic force resting on a rigid foundation.The investigation is carried out within the framework of the piecewise homogeneous body model by utilizing the exact equations of motion and relations of the linear theory of electro-elasticity.It is assumed that there is a shear-spring-type imperfect contact between the layers,but a complete contact between the plate-strip and the rigid foundation.A mathematical model of the problem is constructed,and the governing equations of motion are solved by employing the finite element method（FEM）.Numerical results illustrating the influence of a change in the value of the shear-spring parameter on the dynamic response of the plate-strip are then presented.展开更多
Stimuli-responsive molecules are highly desirable in different scenario such as smart materials,bio-imaging,and environment monitoring.Herein,a series of hetero polycycles which show optical response toward chemical s...Stimuli-responsive molecules are highly desirable in different scenario such as smart materials,bio-imaging,and environment monitoring.Herein,a series of hetero polycycles which show optical response toward chemical stimuli are synthesized from trithiasumanene(TTS).The TTS is transformed into ortho-quinone form,which then undergoes three-component Debus-Radziszewski reaction with aldehydes and ammonia to give oxazole-fused TTS(2-6).The thiophene rings on 3-5 are selectively oxidized to thiophene-S,S-dioxides,affording 3-3O_(2)-5-3O_(2).It is found that the electronic structures of these compounds are governed by the sub-stituents on oxazole moiety and oxidation state of thiophene ring.Moreover,these hetero polycycles exhibit optical response toward different chemical stimuli.Particularly,compounds 6 and 3-3O_(2) can serve as fluorescence detectors for harmful chemicals sulfide ions(S2-/HS-)and aniline,respectively.This work indicates that TTS is a promising precursor for the creation of responsive materials.展开更多
Responsive soft materials capable of complex,reversible,and rapid geometric deformations under external stimuli hold significant potential for applications in minimally invasive medicine,wearable devices,and soft robo...Responsive soft materials capable of complex,reversible,and rapid geometric deformations under external stimuli hold significant potential for applications in minimally invasive medicine,wearable devices,and soft robotics.In this study,we present a novel approach for designing reconfigurable three dimensional(3D)deformable magnetic soft materials through photothermal programming.By embedding hard magnetic particles within a polymer matrix composed of fibrous polypyrrole(PPy)and semi-crystalline polymer,we develop magnetic composites that can be remotely controlled to achieve precise,programmable deformations under an external magnetic field.The key innovation lies in utilizing the photothermal effect of PPy,which temporarily alters the viscosity of the composite when irradiated with infrared light,allowing dynamic orientation of the magnetic particles.Upon cooling,the magnetic anisotropy is solidified,enabling rapid and reversible geometric changes.This method allows for intricate control over the magnetization distribution,leading to the development of multifunctional devices with various potential applications such as complex 3D deformations for soft robotics,multimodal electrical switches,rewritable quick response codes,and shape-adaptable grippers.Our study not only enhances the understanding of magnetic moment programming in soft materials but also opens new avenues for the design of adaptive and responsive materials for advanced technological applications.展开更多
Solvent free DNA-surfactant melts are receiving continuous attractions in recent years.Their physical properties could be regulated via changing the alkyl chain length of surfactants.As an ideal external stimulus,ligh...Solvent free DNA-surfactant melts are receiving continuous attractions in recent years.Their physical properties could be regulated via changing the alkyl chain length of surfactants.As an ideal external stimulus,light has been used in the regulation of mechanical properties of DNA thermotropic liquid crystal(TLC)containing an azobenzene motif,while in this case,the UV light is the only effective excitation source.However,in comparison with visible light,UV light causes damage to DNA and has low tissue-penetration efficiency problem.In this work,a new type of DNA-didodecyldimethylammonium bromide(DNA-DDAB)TLCs fabricating with gold nanoparticles(AuNPs)was demonstrated.The visible light-induced photothermal effect of AuNPs could change the mechanical properties of AuNPs/DNA-DDAB TLCs,as shown by clearly boundary motion activity and viscoelasticity change.Furthermore,the ratio of AuNPs and charge stoichiometry of DNA:DDAB also affected photocurrent generation property of these DNA melts.The development of this visible light responsive DNA melt might facilitate the related studies in biomedicine and biomaterials.展开更多
Soft robots based on stimuli-responsive materials,such as those responsive to thermal,magnetic,or light stimuli,hold great potential for adaptive locomotion and multifunc-tionality in complex environments.Among these,...Soft robots based on stimuli-responsive materials,such as those responsive to thermal,magnetic,or light stimuli,hold great potential for adaptive locomotion and multifunc-tionality in complex environments.Among these,liquid crystal elastomers(LCEs)and magnetic microparticles have emerged as particularly promising candidates,leverag-ing their thermal responsiveness and magnetic controllability,respectively.However,integrating these modes to achieve synergistic multimodal actuation remains a signif-icant challenge.Here,we present the thermo-magnetic petal morphing robot,which combines LCEs with embedded magnetic microparticles to enable reversible shape morphing via remote light-to-thermal actuation and high-speed rolling locomotion under external magnetic fields.The robot can achieve rapid deformation under near-infrared light,transitioning from a closed spherical to an open cross-like configuration with consistent shape recovery across multiple cycles,and demonstrates a maximum locomotion speed of 30 body lengths per second,outperforming many state-of-the-art soft robots.Moreover,the robot’s performance remains robust across dry,wet,and underwater conditions,with adjustable magnetic particle concentrations allow-ing tunable actuation performance.Our work addresses the need for soft robots with enhanced versatility and adaptability in complex environments,paving the way for applications in areas such as targeted drug delivery and industrial material handling.展开更多
Recent advancements in high-energy terahertz(THz)sources,driven by powerful laser systems,now enable the generation of ultrashort THz pulses with energies up to several millijoules,spanning frequencies from 1 to 30 TH...Recent advancements in high-energy terahertz(THz)sources,driven by powerful laser systems,now enable the generation of ultrashort THz pulses with energies up to several millijoules,spanning frequencies from 1 to 30 THz.A key breakthrough is developing a reliable single-shot detection method,essential for measuring the electric field of these broadband,low-repetition-rate pulses,which is vital for exploring the complex dynamics of THz emission and studying extreme nonlinear material responses in this range.Existing detection methods have been limited to lower frequencies.Here,we introduce the first potentially single-shot-capable THz detection technique for capturing ultra-broadband waveforms.Utilizing a 1-μm-thick SiN detection chip,we exploit THz field-induced second harmonic generation to achieve real-time monitoring of THz waveforms with frequency content up to 30 THz.By adjusting the angle between the THz and optical probe beams,we can fine-tune the detection window for enhanced flexibility.Our novel THz detector is ideally suited for high-energy,low-repetition-rate sources,unlocking new frontiers in THz research.展开更多
Bistable[c2]daisy chain rotaxanes represent a par-ticularly intriguing class of interlocked molecules that can produce internal sliding movements with a net contraction or extension at the single-molecule level.
Despite noteworthy technological progress and promising preclinical trials,brain disorders are still the leading causes of death globally.Extracellular vesicles(EVs),nano-/micro-sized membrane vesicles carrying bioact...Despite noteworthy technological progress and promising preclinical trials,brain disorders are still the leading causes of death globally.Extracellular vesicles(EVs),nano-/micro-sized membrane vesicles carrying bioactive molecules,are involved in cellular communication.Based on their unique properties,including superior biocompatibility,non-immunogenicity,and blood-brain barrier(BBB)penetration,EVs can shield their cargos from immune clearance and transport them to specific site,which have attracted increasing interests as novel nanocarriers for brain disorders.However,considering the limitations of native EVs,such as poor encapsulation efficiency,inadequate targeting capability,uncontrolled drug release,and limited production,researchers bioengineer EVs to fully exploit the clinical potential.Herein,this review initially describes the basic properties,biogenesis,and uptake process of EVs from different subtypes.Then,we highlight the application of EVs derived from different sources for personalized therapy and novel strategies to construct bioengineered EVs for enhanced diagnosis and treatment of brain disorders.Besides,it also presents a systematic comparison between EVs and other brain-targeted nanocarriers.Finally,existing challenges and future perspectives of EVs have been discussed,hoping to bolster the research from benchtop to bedside.展开更多
DNA-mediated programming is emerging as an effective technology that enables controlled dynamic assembly/disassembly of inorganic nanocrystals(NC)with precise numbers and spatial locations for biomedical imaging appli...DNA-mediated programming is emerging as an effective technology that enables controlled dynamic assembly/disassembly of inorganic nanocrystals(NC)with precise numbers and spatial locations for biomedical imaging applications.In this review,we will begin with a brief overview of the rules of NC dynamic assembly driven by DNA ligands,and the research progress on the relationship between NC assembly modes and their biomedical imaging performance.Then,we will give examples on how the driven program is designed by different interactions through the configuration switching of DNA-NC conjugates for biomedical applications.Finally,we will conclude with the current challenges and future perspectives of this emerging field.Hopefully,this review will deepen our knowledge on the DNA-guided precise assembly of NCs,which may further inspire the future development of smart chemical imaging devices and high-performance biomedical imaging probes.展开更多
Optic-electric responsive materials have attracted much attention for their applications in temperaturesensing,actuators,and memory switches.However,it is a challenge to integrate various functions to form multifuncti...Optic-electric responsive materials have attracted much attention for their applications in temperaturesensing,actuators,and memory switches.However,it is a challenge to integrate various functions to form multifunctional responsive materials.As molecule-based hybrid materials usually consist of organic and inorganic components,the introduction of multiple functions can be achieved through structural construction.Thus far,even though fulltemperature cover is required for device applications,fulltemperature covered multi-switchable hybrid materials have rarely been successfully synthesized.Herein,the dynamic[(CH3)3NOH]+cation and luminous center Mn(II)were introduced to form a hybrid material[(CH3)3NOH][Mn Cl3],showing multiple temperature-responsive behaviors.Upon temperature change,it exhibits multi-state dielectric switching response and intensity or peak shift response of luminous in full-temperature range(low,room,and high temperatures).These responsive behaviors are triggered by the motion or reorientation of[(CH3)3NOH]+cations and inorganic framework.Overall,the switchable photoelectric material has potential applications in multiple encrypted storage and sensor devices.展开更多
Luminescent materials exhibiting emission switching in the solid state have drawn much attention though there is still no clear design strategy for such materials. In this letter, we reported the crystallization induc...Luminescent materials exhibiting emission switching in the solid state have drawn much attention though there is still no clear design strategy for such materials. In this letter, we reported the crystallization induced emission enhancement (CIEE) of di(4-ethoxyphenyl)dibenzofulvene (1), and achieved switching its emission among four different colors through modulation of its molecular packing patterns. We have investigated its potential application as optical recording materials. The twisted conformations of CIEE compounds afford morphology dependent emission and facilitate tuning their emission through modulation of molecular packing patterns. Thus we provide a possible design strategy for solid stimulus responsive luminescent materials.展开更多
基金Supported by the National Natural Science Foundation of China(No.52073181,No.52273134).
文摘AIM:To investigate the biocompatibility and bacterial adhesion properties of light responsive materials(LRM)and analyze the feasibility and biosafety of employing LRM in the preparation of accommodative intraocular lenses(AIOLs).METHODS:Employing fundamental experimental research techniques,LRM with human lens epithelial cells(hLECs)and human retinal pigment epithelium cells(ARPE-19 cells)were co-cultured.Commercially available intraocular lenses(IOLs)were used as controls to perform cell counting kit-8(CCK-8),cell staining under varying light intensities,cell adhesion and bacterial adhesion experiments.RESULTS:LRM exhibited a stronger inhibitory effect on the proliferation of ARPE19 cells than commercially available IOLs when co-cultured with the undiluted extract for 96h(P<0.05).Under other culturing conditions,the effects on the proliferation of hLECs and ARPE-19 cells were not significantly different between the two materials.Under the influence of light irradiation at intensities of 200 and 300 mW/cm^(2),LRM demonstrated a markedly higher inhibitory effect on the survival of hLECs compared to commercially available IOLs(P<0.0001).They also showed a stronger suppressive effect on the survival rate of ARPE-19 cells,with significant differences observed at 200 mW/cm^(2)(P<0.001)and extremely significant differences at 300 mW/cm^(2)(P<0.0001).Additionally,compared to commercially available IOLs,LRM had a higher number of cells adhering to their surface(P<0.05),as well as a significantly greater number of adherent bacterium(P<0.0001).CONCLUSION:LRM,characterized by their excellent non-contact tunable deformability and low cytotoxicity to ocular tissues,show considerable potential for use in the fabrication of AIOLs.These materials demonstrate strong cell adhesion;however,during photothermal conversion processes involving shape deformation under various light intensities,the resultant temperature rise may harm surrounding cells.These factors suggest that while the material plays a positive role in reducing the incidence of posterior capsule opacification(PCO),it also poses potential risks for retinal damage.Additionally,the strong bacterial adhesion of these materials indicates an increased risk of endophthalmitis.
基金support provided by the Hong Kong RGC Theme-based Research Scheme(No.AoE/M-402/20)Hong Kong RGC Area of Excellence Scheme(No.AoE/E-101/23-N)+1 种基金Hong Kong RGC Theme-based Research Scheme(No.T45-406/23-R)the Hong Kong Innovation and Technology Commission via the Hong Kong Branch of National Precious Metals Material Engineering Research Center.
文摘Soft actuators and stimuli responsive materials are highlighted in the research field for their enormous potential in transit tasks,sensing,and biomedical devices,particularly the magnetic responsive soft actu-ators driven by magnetic force remotely.Nevertheless,the further study of magnetic responsive actuators with complex three-dimensional geometries and multiple functions is still limited by uncomplicated de-sign and flexible locomotion.This work provides a novel scheme integrating the origami method and modular designs,which defines the inner properties of magnetic material,extending the functions of magnetic responsive actuators with various modules.The directions of the inner magnetic moments can be programmed and the deformation degrees can be regulated by this approach,which promotes the fabrication of complicated soft actuators with multiple functions by integrating with modular designs.Especially,a movable actuator with various sensing modulus is designed by the origami method,which can perform the sensing application to external ultra-violet(UV),heat,and pH stimuli.Moreover,a mi-croneedle modular actuator which can be controlled wirelessly by a magnetic field was demonstrated for the potential application in the biomedical field.This proposed scheme for engineering magnetic respon-sive material with modular designs has shown great potential to improve the feasibility,versatility,and multiple functionalities of soft actuators.
基金supported by the National Natural Science Foundation of China(Nos.22071273 and 21821003)Fundamental Research Funds for the Central Universities,Sun Yat-sen University(No.23lgzy001)。
文摘Multi-stimuli responsive materials controlled and coupled by two or more channels have a broad range of applications in the field of switches,memories,and molecular machines.The exploration of the material is currently focused on the pure organic system,which limits the development o such materials greatly.In this work,we present a new chiral organic-inorganic hybrid salt,(R-3hydroxypyrrolidinium)_(2)[Fe(CN)_(5)(NO)](1),which exhibits rare multi-stimuli responsive behaviors in ther mal,mechanical and optical channels.In detail,1 undergoes a C2-P2_(1)22_(1) phase transition deriving from the thermal motion of organic cations with the increase of temperature,but the reverse transition can only be induced by mechanical pressure.Moreover,polycrystalline hybrid salt showed photo-responsive performance,i.e.,the ground-state N-bound nitrosyl ligand adopts two configurations in excited state caused by light in 532 nm irradiation,accompanying with a photo-induced structural transformation o the anionic framework.Namely,the thermal motion characteristics of organic cations,the photoresponse characteristics of anionic inorganic skeleton and the pressure characteristics from hydrogen bonds are si multaneously integrated in 1.This unprecedented coupling mechanism of multi-stimuli responses make1 a potential candidate for future multichannel data storage applications.
文摘How the wave propagation analysis plays a key role in the studies of dynamic response of materials at high strain rates is analyzed. For the wave propagation technique, the followings are important: the loading and unloading constitutive relation presumed, the positions of the sensors embedded, the interactions between loading waves and unloading waves. For the split Hopkinson pressure bar (SHPB) technique, the assumption of one-dimensional stress wave propagation and the assumption of stress uniformity along the specimen should be satisfied. When the larger diameter bars are employed, the wave dispersion effects should be considered, including the high frequency oscillations, non-uniform stress distribution across the bar section, increase of rise time, and amplitude attenuation. The stress uniformity along the specimen is influenced by the reflection times in specimen, the wave impedance ratio of the specimen and the bar, and the waveform.
基金Supported by the Natural Science Foundation of Hebei Province under Grant No E2012201084the National University Students’ Innovative Training Program under Grant No 201410075004
文摘Realizing the accurate characterization for the dynamic damage process is a great challenge. Here we carry out testing simultaneously for dynamic monitoring and acoustic emission （AE） statistical analysis towards fiber composites under mode-Ⅱ delamination damage. The load curve, AE relative energy, amplitude distribution, and amplitude spectrum are obtained and the delamination damage mechanism of the composites is investigated by the microscopic observation of a fractured specimen. The results show that the micro-damage accumulation around the crack tip region has a great effect on the evolutionary process of delamination. AE characteristics and amplitude spectrum represent the damage and the physical mechanism originating from the hierarchical microstructure. Our finding provides a novel aud feasible strategy to simultaneously evaluate the dynamic response and micro-damage mechanism for fiber composites.
基金supported by the National Natural Science Foundation of China(Nos.21673038,21771037,21805033)Natural Science Foundation of Jiangsu Province(JSNSF,No.BK20170659)。
文摘Stimulus re s ponsive materials can provide a variety of desirable properties in one equipment unit,such as optoelectronic devices,data communications,actuators,memories,sensors and capacitors.However,it remains a large challenge to design such stimulus responsive materials,especially functional materials having both dielectric switch and second harmonic generation(SHG).Here,a new stimuli-responsive switchable material [(CH_(3))_(3)N(CH_(2))_(2)Cl]_(2)]Mn(SCN)_(4)(H_(2)O)_(2)] was discovered as a potential secondharmonic generation(SHG) dielectric switch.It is worth noting that it has SHG characteristics before and after undergoing reversible high-temperature phase transitions.In this work,we successfully refined the tetramethylammonium cation to obtain a quasi-spherical cation,which is tetramethylchloroethylamine(TMCEM) cation.By substituting H with a halogen,the increased steric hindrance of the molecular makes energy barrier increased,resulting in the reversible high-temperature phase transition.At the same time,the interactions of quasi-spherical cations and [Mn(SCN)_(4)(H_(2)O)_(2)]^(2-) anions affect a noncentrosymmetric structure to induce the SHG effect.These findings provide a new approach to design novel functional switch materials.
基金supported by the Youth Innovation Promotion Association CAS(grant no.2018040)(J.M.Z.)the National Natural Science Foundation of China(grant nos.52173292 and U2004211)(J.M.Z.and J.Z.)the National Key Research and Development Project(grant no.2020YFC1910303)(J.Z.).
文摘Constructingeco-friendlystimuli-responsivephosphorescence materials remains challenging and fascinating.Herein,we use natural cellulose as the rawmaterial to prepare pH-responsive room-temperature phosphorescent(RTP)materials with excellent biodegradability by introducing anionic structures.The introduction of a phenylcarboxylate substituent not only promotes intersystem crossing but also brings about electrostatic-attractive and strong hydrogenbonding interactions,which enhance the intermolecular chain interactions.Therefore,the obtained anionic cellulose derivatives containing phenylcarboxylate groups exhibit ultra-long RTP.More intriguingly,these cellulose-based phosphorescent materials have a distinctive pH-responsive behavior.Under acidic conditions,the carboxylate is converted into the carboxylic acid,resulting in phosphorescence quenching.This process is reversible.Moreover,the obtained cellulosebased phosphorescent materials have excellent processability and can be easily processed into various material forms,such as film,coating,and pattern,by using eco-friendly aqueous solution processing strategies.Such proof-of-concept biomass-based phosphorescent materials with unique pH-responsive behavior and excellent processability have a huge potential in information encryption,advanced anti-counterfeiting,and food monitoring.
基金financially supported by the National Natural Science Foundation of China (Nos. 21875035 and 21991144)。
文摘Deuteration of hydrogen-bonded phase transition crystals can increase the transition temperatures due to the isotope effect. But rare examples show the opposite trend that originates from the structural changes of the hydrogen bond, known as the geometric H/D isotope effect. Herein, we report an organic crystal, diethylammonium hydrogen 1,4-terephthalate, exhibits a reversible structural phase transition and dielectric switching. Structural study shows the cations reside in channels formed by one-dimensional hydrogen-bonded anionic chains and undergo an order-disorder transition at around 206 K. The deuterated counterpart shows an elongation of the O…O hydrogen bond by about 0.005 A. This geometric isotope effect releases the internal pressure of the anionic host on the cation vips and results in a downward shift of the phase transition temperature by 10 K.
基金Funded by National Natural Science Foundation of China(No. 50875253)Natural Science Foundation of Jiangsu Province of China(No. BK2008127)Key Project of Chinese Ministry of Education(NO.107054)
文摘The tribological properties of newly developed friction material were evaluated by statistical analysis of the major affecting factors.The material for investigation was non-metallic friction material synergistically reinforced with aramid fibre and CaSO 4 whisker,which was developed for hoisting applications in coal mine.The response surface method（RSM）was employed to analyze the material performances affected by the independent and interactive effect of the factors under the normal working condition and severe working condition,respectively.Results showed that under the normal working condition,the newly developed material exhibited stable tribological properties which were insensitive to the test conditions.While under the severe working condition,the sliding velocity was the most dominant factor affecting the friction coefficient.Additionally,compared to the commercially available material,the modified material showed superior wear resistance and thermal stability.
基金a member of a research project supported by the Research Fund of Kastamonu University via project num-ber Kü-BAP01/2016-4
文摘In this paper,we consider the dynamic response of a pre-stressed sandwich plate-strip with a piezoelectric core and elastic layers under the action of a time-harmonic force resting on a rigid foundation.The investigation is carried out within the framework of the piecewise homogeneous body model by utilizing the exact equations of motion and relations of the linear theory of electro-elasticity.It is assumed that there is a shear-spring-type imperfect contact between the layers,but a complete contact between the plate-strip and the rigid foundation.A mathematical model of the problem is constructed,and the governing equations of motion are solved by employing the finite element method（FEM）.Numerical results illustrating the influence of a change in the value of the shear-spring parameter on the dynamic response of the plate-strip are then presented.
基金This work was supported by the National Key R&D Program of China(No.2017YFA0204903)the National Natural Science Foundation of China(No.21871119).
文摘Stimuli-responsive molecules are highly desirable in different scenario such as smart materials,bio-imaging,and environment monitoring.Herein,a series of hetero polycycles which show optical response toward chemical stimuli are synthesized from trithiasumanene(TTS).The TTS is transformed into ortho-quinone form,which then undergoes three-component Debus-Radziszewski reaction with aldehydes and ammonia to give oxazole-fused TTS(2-6).The thiophene rings on 3-5 are selectively oxidized to thiophene-S,S-dioxides,affording 3-3O_(2)-5-3O_(2).It is found that the electronic structures of these compounds are governed by the sub-stituents on oxazole moiety and oxidation state of thiophene ring.Moreover,these hetero polycycles exhibit optical response toward different chemical stimuli.Particularly,compounds 6 and 3-3O_(2) can serve as fluorescence detectors for harmful chemicals sulfide ions(S2-/HS-)and aniline,respectively.This work indicates that TTS is a promising precursor for the creation of responsive materials.
基金supported by the National Natural Science Foundation of China(52225307 and 22105193)the CAS Project for Young Scientists in Basic Research(YSBR-004)+1 种基金the Fundamental Research Funds for the Central Universities(20720220007 and 20720220011)partially carried out at the University of Science and Technology of China(USTC)Center of Micro and Nanoscale Research and Fabrication。
文摘Responsive soft materials capable of complex,reversible,and rapid geometric deformations under external stimuli hold significant potential for applications in minimally invasive medicine,wearable devices,and soft robotics.In this study,we present a novel approach for designing reconfigurable three dimensional(3D)deformable magnetic soft materials through photothermal programming.By embedding hard magnetic particles within a polymer matrix composed of fibrous polypyrrole(PPy)and semi-crystalline polymer,we develop magnetic composites that can be remotely controlled to achieve precise,programmable deformations under an external magnetic field.The key innovation lies in utilizing the photothermal effect of PPy,which temporarily alters the viscosity of the composite when irradiated with infrared light,allowing dynamic orientation of the magnetic particles.Upon cooling,the magnetic anisotropy is solidified,enabling rapid and reversible geometric changes.This method allows for intricate control over the magnetization distribution,leading to the development of multifunctional devices with various potential applications such as complex 3D deformations for soft robotics,multimodal electrical switches,rewritable quick response codes,and shape-adaptable grippers.Our study not only enhances the understanding of magnetic moment programming in soft materials but also opens new avenues for the design of adaptive and responsive materials for advanced technological applications.
基金supported by the National Natural Science Foundation of China(21805150)Natural Science Foundation of Shandong Province(ZR2019BB034)+1 种基金the Taishan Scholar Program of Shandong Province of China(ts20110829)Science and Technology Planning Project of Guangdong Province of China(2016B030309002)
文摘Solvent free DNA-surfactant melts are receiving continuous attractions in recent years.Their physical properties could be regulated via changing the alkyl chain length of surfactants.As an ideal external stimulus,light has been used in the regulation of mechanical properties of DNA thermotropic liquid crystal(TLC)containing an azobenzene motif,while in this case,the UV light is the only effective excitation source.However,in comparison with visible light,UV light causes damage to DNA and has low tissue-penetration efficiency problem.In this work,a new type of DNA-didodecyldimethylammonium bromide(DNA-DDAB)TLCs fabricating with gold nanoparticles(AuNPs)was demonstrated.The visible light-induced photothermal effect of AuNPs could change the mechanical properties of AuNPs/DNA-DDAB TLCs,as shown by clearly boundary motion activity and viscoelasticity change.Furthermore,the ratio of AuNPs and charge stoichiometry of DNA:DDAB also affected photocurrent generation property of these DNA melts.The development of this visible light responsive DNA melt might facilitate the related studies in biomedicine and biomaterials.
基金Shenzhen Science and Technology Program,Grant/Award Numbers:JCYJ20210324132810026,KQTD20210811090146075,GXWD20220811164014001National Natural Science Foundation of China,Grant/Award Numbers:52375175,52005128Guangdong Basic and Applied Basic Research Foundation,Grant/Award Number:2024A1515240015。
文摘Soft robots based on stimuli-responsive materials,such as those responsive to thermal,magnetic,or light stimuli,hold great potential for adaptive locomotion and multifunc-tionality in complex environments.Among these,liquid crystal elastomers(LCEs)and magnetic microparticles have emerged as particularly promising candidates,leverag-ing their thermal responsiveness and magnetic controllability,respectively.However,integrating these modes to achieve synergistic multimodal actuation remains a signif-icant challenge.Here,we present the thermo-magnetic petal morphing robot,which combines LCEs with embedded magnetic microparticles to enable reversible shape morphing via remote light-to-thermal actuation and high-speed rolling locomotion under external magnetic fields.The robot can achieve rapid deformation under near-infrared light,transitioning from a closed spherical to an open cross-like configuration with consistent shape recovery across multiple cycles,and demonstrates a maximum locomotion speed of 30 body lengths per second,outperforming many state-of-the-art soft robots.Moreover,the robot’s performance remains robust across dry,wet,and underwater conditions,with adjustable magnetic particle concentrations allow-ing tunable actuation performance.Our work addresses the need for soft robots with enhanced versatility and adaptability in complex environments,paving the way for applications in areas such as targeted drug delivery and industrial material handling.
基金supported by the Independent Research Fund Denmark(project THz-GRIP:2035-00365B).
文摘Recent advancements in high-energy terahertz(THz)sources,driven by powerful laser systems,now enable the generation of ultrashort THz pulses with energies up to several millijoules,spanning frequencies from 1 to 30 THz.A key breakthrough is developing a reliable single-shot detection method,essential for measuring the electric field of these broadband,low-repetition-rate pulses,which is vital for exploring the complex dynamics of THz emission and studying extreme nonlinear material responses in this range.Existing detection methods have been limited to lower frequencies.Here,we introduce the first potentially single-shot-capable THz detection technique for capturing ultra-broadband waveforms.Utilizing a 1-μm-thick SiN detection chip,we exploit THz field-induced second harmonic generation to achieve real-time monitoring of THz waveforms with frequency content up to 30 THz.By adjusting the angle between the THz and optical probe beams,we can fine-tune the detection window for enhanced flexibility.Our novel THz detector is ideally suited for high-energy,low-repetition-rate sources,unlocking new frontiers in THz research.
基金The authors thank the European Research Council(ERC StG Agreement No.257099)the H2020 FET-Open Mag-nify Project(Grant Agreement No.801378)+2 种基金the ANR Integrations(14-CE06-0021)the LabEx CSC,the CNRS,the University of Strasbourgthe Institut Universi-taire de France(IUF).
文摘Bistable[c2]daisy chain rotaxanes represent a par-ticularly intriguing class of interlocked molecules that can produce internal sliding movements with a net contraction or extension at the single-molecule level.
基金support from National Natural Science Foundation of China(Nos.82274104,81903557,and 82074024)Natural Science Foundation of Jiangsu Province(No.BK20190802)+3 种基金Young Elite Scientists Sponsorship Program by CACM(No.2021-QNRC2-A01)Natural Science Foundation Youth Project of Nanjing University of Chinese Medicine(No.NZY81903557)College Students’Innovative Entrepreneurial Training of Jiangsu Province(No.202110315021)College Students’Innovative Entrepreneurial Training of Kangyuan School of Chinese Herbal Medicine of Nanjing University of Chinese Medicine(No.kyxysc12).
文摘Despite noteworthy technological progress and promising preclinical trials,brain disorders are still the leading causes of death globally.Extracellular vesicles(EVs),nano-/micro-sized membrane vesicles carrying bioactive molecules,are involved in cellular communication.Based on their unique properties,including superior biocompatibility,non-immunogenicity,and blood-brain barrier(BBB)penetration,EVs can shield their cargos from immune clearance and transport them to specific site,which have attracted increasing interests as novel nanocarriers for brain disorders.However,considering the limitations of native EVs,such as poor encapsulation efficiency,inadequate targeting capability,uncontrolled drug release,and limited production,researchers bioengineer EVs to fully exploit the clinical potential.Herein,this review initially describes the basic properties,biogenesis,and uptake process of EVs from different subtypes.Then,we highlight the application of EVs derived from different sources for personalized therapy and novel strategies to construct bioengineered EVs for enhanced diagnosis and treatment of brain disorders.Besides,it also presents a systematic comparison between EVs and other brain-targeted nanocarriers.Finally,existing challenges and future perspectives of EVs have been discussed,hoping to bolster the research from benchtop to bedside.
基金support by the National Key Research and Development Program of China(2022YFB3203801,2022YFB3203804,2022YFB3203800)the Leading Talent of“Ten Thousand Plan”-National High-Level Talents Special Support Plan,National Natural Science Foundation of China(32071374)+4 种基金Program of Shanghai Academic Research Leader under the Science and Technology Innovation Action Plan(21XD1422100)Program of Shanghai Science and Technology Development(22TS1400700)Zhejiang Provincial Natural Science Foundation of China(LR22C100001)Innovative Research Team of High-Level Local Universities in Shanghai(SHSMU-ZDCX20210900)CAS Interdisciplinary Innovation Team(JCTD-2020-08).
文摘DNA-mediated programming is emerging as an effective technology that enables controlled dynamic assembly/disassembly of inorganic nanocrystals(NC)with precise numbers and spatial locations for biomedical imaging applications.In this review,we will begin with a brief overview of the rules of NC dynamic assembly driven by DNA ligands,and the research progress on the relationship between NC assembly modes and their biomedical imaging performance.Then,we will give examples on how the driven program is designed by different interactions through the configuration switching of DNA-NC conjugates for biomedical applications.Finally,we will conclude with the current challenges and future perspectives of this emerging field.Hopefully,this review will deepen our knowledge on the DNA-guided precise assembly of NCs,which may further inspire the future development of smart chemical imaging devices and high-performance biomedical imaging probes.
基金financially supported by the National Natural Science Foundation of China(21991141)the Natural Science Foundation of Zhejiang Province(LZ20B010001)Zhejiang Normal University。
文摘Optic-electric responsive materials have attracted much attention for their applications in temperaturesensing,actuators,and memory switches.However,it is a challenge to integrate various functions to form multifunctional responsive materials.As molecule-based hybrid materials usually consist of organic and inorganic components,the introduction of multiple functions can be achieved through structural construction.Thus far,even though fulltemperature cover is required for device applications,fulltemperature covered multi-switchable hybrid materials have rarely been successfully synthesized.Herein,the dynamic[(CH3)3NOH]+cation and luminous center Mn(II)were introduced to form a hybrid material[(CH3)3NOH][Mn Cl3],showing multiple temperature-responsive behaviors.Upon temperature change,it exhibits multi-state dielectric switching response and intensity or peak shift response of luminous in full-temperature range(low,room,and high temperatures).These responsive behaviors are triggered by the motion or reorientation of[(CH3)3NOH]+cations and inorganic framework.Overall,the switchable photoelectric material has potential applications in multiple encrypted storage and sensor devices.
基金the National Natural Science Foundation of China (51173018)the National Basic Research Program of China (973 program, 2013CB834704)
文摘Luminescent materials exhibiting emission switching in the solid state have drawn much attention though there is still no clear design strategy for such materials. In this letter, we reported the crystallization induced emission enhancement (CIEE) of di(4-ethoxyphenyl)dibenzofulvene (1), and achieved switching its emission among four different colors through modulation of its molecular packing patterns. We have investigated its potential application as optical recording materials. The twisted conformations of CIEE compounds afford morphology dependent emission and facilitate tuning their emission through modulation of molecular packing patterns. Thus we provide a possible design strategy for solid stimulus responsive luminescent materials.
