Titanium dioxide (TiO_2) thin films were prepared on microscopes slides by sol-gel and dip-coating processes from specially formulated sols.The results show that there exists anatase and rutile structure of TiO_2 when...Titanium dioxide (TiO_2) thin films were prepared on microscopes slides by sol-gel and dip-coating processes from specially formulated sols.The results show that there exists anatase and rutile structure of TiO_2 when heat treatment temperature is 450℃,and at 800℃,TiO_2 particle size is of below 100 nm and rutile structure is presented.In the range of 360 nm~400 nm the transmittance of TiO_2 sol increases with the increasing of the concentration of Ti(OC_4H_9)_4 in ethanol solution. The transmittance of TiO_2 films with various number of the layer is measured to be 0% below 320 nm,and the three-layer TiO_2 film is of the best UV resistance in the range of 320 nm~400 nm.展开更多
As a specific name,Chinese traditional drama appeared in the 1960s,which specifically refers to the reserved plays of various traditional dramas that coexisted with modern dramas and newly edited historical dramas bef...As a specific name,Chinese traditional drama appeared in the 1960s,which specifically refers to the reserved plays of various traditional dramas that coexisted with modern dramas and newly edited historical dramas before the foundation of New China.Traditional drama has aesthetic characteristics such as freehand,stylization,singing and dancing,and it has profoundly affected the aesthetic taste of the Chinese people because of its rich spiritual and aesthetic accumulation.展开更多
Flexible strain sensors with high sensitivity,wide detection range,and low detection limit have continuously attracted great interest due to their tremendous application potential in areas such as health/medical-care,...Flexible strain sensors with high sensitivity,wide detection range,and low detection limit have continuously attracted great interest due to their tremendous application potential in areas such as health/medical-care,human-machine interface,as well as safety and security.While both of a high sensitivity and a wide working range are desired key parameters for a strain sensor,they are usually contrary to each other to be achieved on the same sensor due to the tightly structure dependence of both of them.Here,a flexible strain sensor with both high sensitivity and wide strain detection range is prepared based on the design of an integrated membrane containing both of parallel aligned and randomly aligned carbon nanofibers(CNFs).The parallel aligned CNF membrane(p-CNF)exhibits a low strain detection limit and high sensitivity,while the random aligned CNF membrane(r-CNF)exhibits a large strain detection range.Taking the advantages of both p-CNF and r-CNF,the strain sensor with stacked p-CNF and r-CNF(p/r-CNF)exhibits both high sensitivity and wide working range.Its gauge factor(GF)is 1,272 for strains under 0.5%and 2,266 for strain from 70%to 100%.At the same time,it can work in a wide strain range of 0.005%to 100%,fulfilling the requirements for accurately detecting full-range human motions.We demonstrated its applications in the recognition of facial expressions and joint movements.Furtherly,we constructed an intelligent lip-language recognition system,which can accurately track phonetic symbols and may help people with language disabilities,proving the potential of this strain sensor in health management and medical assistance.Besides,we foresee that the dual-alignment structure design of the p/r-CNF strain sensor may also be applied in the design of other high performance sensors.展开更多
Stretchable and flexible supercapacitors are highly desired due to their many potential applications in wearable devices. However, it is challenging to fabricate supercapacitors that can withstand large tensile strain...Stretchable and flexible supercapacitors are highly desired due to their many potential applications in wearable devices. However, it is challenging to fabricate supercapacitors that can withstand large tensile strain while maintaining high performance. Herein, we report an ultra-stretchable wire-shaped supercapacitor based on carbon nanotube@graphene@MnO2 fibers wound around a superelastic core fiber. The supercapacitor can sustain tensile strain up to 850%, which is the highest value reported for this type of device to date, while maintaining stable electrochemical performance. The energy density of the supercapacitor is 3.37 mWh·cm^-3 at a power density of 54.0 mW·cm^-3. The results show that 82% of the specific capacitance is retained after 1,000 stretch-release cycles with strains of 700%, demonstrating the superior durability of the elastic supercapacitor and showcasing its potential application in ultra-stretchable flexible electronics.展开更多
Skin,the largest organ in the human body,is sensitive to external stimuli.In recent years,an increasing number of skin-inspired electronics,including wearable electronics,implantable electronics,and electronic skin,ha...Skin,the largest organ in the human body,is sensitive to external stimuli.In recent years,an increasing number of skin-inspired electronics,including wearable electronics,implantable electronics,and electronic skin,have been developed because of their broad applications in healthcare and robotics.Physical sensors are one of the key building blocks of skin-inspired electronics.Typical physical sensors include mechanical sensors,temperature sensors,humidity sensors,electrophysiological sensors,and so on.In this review,we systematically review the latest advances of skin-inspired mechanical sensors,temperature sensors,and humidity sensors.The working mechanisms,key materials,device structures,and performance of various physical sensors are summarized and discussed in detail.Their applications in health monitoring,human disease diagnosis and treatment,and intelligent robots are reviewed.In addition,several novel properties of skin-inspired physical sensors such as versatility,self-healability,and implantability are introduced.Finally,the existing challenges and future perspectives of physical sensors for practical applications are discussed and proposed.展开更多
Silkworm silk fbers have been woven into textiles for thousands of years,because of their attractive luster,good mechanical properties,excellent biocompatibility,and large-scale production.With the development of huma...Silkworm silk fbers have been woven into textiles for thousands of years,because of their attractive luster,good mechanical properties,excellent biocompatibility,and large-scale production.With the development of human society,preparation of silk fbers with modifed or enhanced properties are highly desirable for potential applications in structural materials and smart textiles.Herein,we realized the reinforcement of multiple properties of silk fbers by feeding silkworms with Ag nanowire(Ag NW)modifed diets.The obtained silk fbers show obviously enhanced comprehensive mechanical properties,including improved tensile strength,elongation at break,tensile modulus,and toughness,which are increased by 37.2%,37.6%,68.3%,and 69.8%,respectively.Furthermore,compared with unmodifed silk,the electrical conductivity and thermal conductivity of modifed silk fbers are improved by 246.4%and 32.1%,respectively.The analysis on the components and structure shows that the incorporated Ag NWs lead to increased content of random coil/α-helix,improved orientation of crystallites,and increased content of Ag compared to pristine silk fbers,which may contribute to the enhanced mechanical,electrical,and thermal properties.展开更多
Smart textiles are attracting great interest.Particularly,air-conditioning textiles are highly desired for their merits in energy conservation and personal temperature/humidity management.Currently,air-conditioning te...Smart textiles are attracting great interest.Particularly,air-conditioning textiles are highly desired for their merits in energy conservation and personal temperature/humidity management.Currently,air-conditioning textiles can be fabricated by two strategies.One uses infrared-radiation-adaptive materials,and the other uses moisture-responsive actuators that can regulate temperature and humidity simultaneously.Here,the fabrication of a silk-yarn switch comprising electrospun highly aligned nanofibers is reported and its application in air-conditioning textiles is demonstrated.Silk yarn rotates in contact with liquid,and can be recovered by drying.The different responses and wetting behaviors of the switch to H_(2)O and C_(2)H_(6)O is investigated.It is argued that alignment and surface hydrophilicity of nanofibers play important roles in this term.To elaborate,actuating trait is mainly controlled by reduction of the surface free energy of aligned silk nanofibers,during the wetting process.As proof of concept,the application of the sweat-driven silk-yarn switch in regulating the temperature/humidity of the human body is demonstrated in this work.Considering the large production,versatile processibility,and good biocompatibility,silk actuator may have practical applications in designing smart switches(or valves)for intelligent textiles,artificial muscles,and other application scenarios.展开更多
Silkworm silk,which is obtained from domesticated Bombyx mori(B.mori),can be produced in a large scale.However,the mechanical properties of silkworm silk are inferior to its counterpart,spider dragline silk.Therefore,...Silkworm silk,which is obtained from domesticated Bombyx mori(B.mori),can be produced in a large scale.However,the mechanical properties of silkworm silk are inferior to its counterpart,spider dragline silk.Therefore,researchers are continuously exploring approaches to reinforce silkworm silk.Herein,we report a facile and scalable hot stretching process to reinforce natural silk fibers obtained from silkworm cocoons.Experimental results show that the obtained hot-stretched silk fibers(HSSFs)retain the chemical components of the original silk fibers while being endowed with increasedβ-sheet nanocrystal content and crystalline orientation,leading to enhanced mechanical properties.Significantly,the average modulus of the HSSFs reaches 21:6±2:8 GPa,which is about twice that of pristine silkworm silk fibers(11:0±1:7 GPa).Besides,the tensile strength of the HSSFs reaches 0:77±0:13 GPa,which is also obviously higher than that of the pristine silk(0:56±0:08 GPa).The results show that the hot stretching treatment is effective and efficient for producing superstiff,strong,and tough silkworm silk fibers.We anticipate this approach may be also effective for reinforcing other natural or artificial polymer fibers or films containing abundant hydrogen bonds.展开更多
Carbon nanotubes(CNTs)hold great promise in many fields because of their unique structures and properties.However,the preparation of CNTs generally involves cumbersome equipment and time-consuming processes.Here,we re...Carbon nanotubes(CNTs)hold great promise in many fields because of their unique structures and properties.However,the preparation of CNTs generally involves cumbersome equipment and time-consuming processes.Here,we report an ultra-fast carbothermal shock(CTS)approach for synthesizing CNTs with a simple homemade setup by employing Joule heating of a carbon substrate.Carbonized silk fabric(CSF)loaded with transition metal salts in ethanol solution was used as the substrate,which was treated with a pulse voltage of 40 V for only 50 ms and then covered with uniform CNTs grown with bimetallic alloy catalyst nanoparticles(diameter:~9 nm).The temperature ramp rate is as high as 105 K/s.The as-obtained sample has a unique fluffy structure similar to the trichobothrium of spiders,endowing it versatile applications such as airflow sensors or air filters.The CTS technique presents an easy-accessible and highly efficient approach for synthesizing CNTs,which may be also applied in synthesizing other nanomaterials.展开更多
文摘Titanium dioxide (TiO_2) thin films were prepared on microscopes slides by sol-gel and dip-coating processes from specially formulated sols.The results show that there exists anatase and rutile structure of TiO_2 when heat treatment temperature is 450℃,and at 800℃,TiO_2 particle size is of below 100 nm and rutile structure is presented.In the range of 360 nm~400 nm the transmittance of TiO_2 sol increases with the increasing of the concentration of Ti(OC_4H_9)_4 in ethanol solution. The transmittance of TiO_2 films with various number of the layer is measured to be 0% below 320 nm,and the three-layer TiO_2 film is of the best UV resistance in the range of 320 nm~400 nm.
基金This thesis is a staged achievement of the National Social Science Fund’s major art projects“Contemporary Inheritance Research of Chinese Traditional Art”(Project Number:19ZD01)“Aesthetics and Art Keyword Research”(Project Number:17ZDA017).
文摘As a specific name,Chinese traditional drama appeared in the 1960s,which specifically refers to the reserved plays of various traditional dramas that coexisted with modern dramas and newly edited historical dramas before the foundation of New China.Traditional drama has aesthetic characteristics such as freehand,stylization,singing and dancing,and it has profoundly affected the aesthetic taste of the Chinese people because of its rich spiritual and aesthetic accumulation.
基金supported by the National Natural Science Foundation of China(Nos.52125201 and 21975141)the National Key Research and Development Program of China(No.2020YFA0210702).
文摘Flexible strain sensors with high sensitivity,wide detection range,and low detection limit have continuously attracted great interest due to their tremendous application potential in areas such as health/medical-care,human-machine interface,as well as safety and security.While both of a high sensitivity and a wide working range are desired key parameters for a strain sensor,they are usually contrary to each other to be achieved on the same sensor due to the tightly structure dependence of both of them.Here,a flexible strain sensor with both high sensitivity and wide strain detection range is prepared based on the design of an integrated membrane containing both of parallel aligned and randomly aligned carbon nanofibers(CNFs).The parallel aligned CNF membrane(p-CNF)exhibits a low strain detection limit and high sensitivity,while the random aligned CNF membrane(r-CNF)exhibits a large strain detection range.Taking the advantages of both p-CNF and r-CNF,the strain sensor with stacked p-CNF and r-CNF(p/r-CNF)exhibits both high sensitivity and wide working range.Its gauge factor(GF)is 1,272 for strains under 0.5%and 2,266 for strain from 70%to 100%.At the same time,it can work in a wide strain range of 0.005%to 100%,fulfilling the requirements for accurately detecting full-range human motions.We demonstrated its applications in the recognition of facial expressions and joint movements.Furtherly,we constructed an intelligent lip-language recognition system,which can accurately track phonetic symbols and may help people with language disabilities,proving the potential of this strain sensor in health management and medical assistance.Besides,we foresee that the dual-alignment structure design of the p/r-CNF strain sensor may also be applied in the design of other high performance sensors.
基金supported by the National Natural Science Foundation of China(52125201 and 21975141)the National Key Basic Research and Development Program of China(2020YFA0210702)。
基金This work was supported by the National Natural Science Foundation of China (Nos. 51422204, 51372132, and 51672153) and the National Basic Research Program of China (Nos. 2016YFA0200103 and 2013CB228506).
文摘Stretchable and flexible supercapacitors are highly desired due to their many potential applications in wearable devices. However, it is challenging to fabricate supercapacitors that can withstand large tensile strain while maintaining high performance. Herein, we report an ultra-stretchable wire-shaped supercapacitor based on carbon nanotube@graphene@MnO2 fibers wound around a superelastic core fiber. The supercapacitor can sustain tensile strain up to 850%, which is the highest value reported for this type of device to date, while maintaining stable electrochemical performance. The energy density of the supercapacitor is 3.37 mWh·cm^-3 at a power density of 54.0 mW·cm^-3. The results show that 82% of the specific capacitance is retained after 1,000 stretch-release cycles with strains of 700%, demonstrating the superior durability of the elastic supercapacitor and showcasing its potential application in ultra-stretchable flexible electronics.
基金National Key Basic Research and Development Program,Grant/Award Number:2016YFA0200103National Natural Science Foundation of China,Grant/Award Numbers:21975141,51672153National Program for Support of Top-notch Young Professionals,Grant/Award Number:N/A。
文摘Skin,the largest organ in the human body,is sensitive to external stimuli.In recent years,an increasing number of skin-inspired electronics,including wearable electronics,implantable electronics,and electronic skin,have been developed because of their broad applications in healthcare and robotics.Physical sensors are one of the key building blocks of skin-inspired electronics.Typical physical sensors include mechanical sensors,temperature sensors,humidity sensors,electrophysiological sensors,and so on.In this review,we systematically review the latest advances of skin-inspired mechanical sensors,temperature sensors,and humidity sensors.The working mechanisms,key materials,device structures,and performance of various physical sensors are summarized and discussed in detail.Their applications in health monitoring,human disease diagnosis and treatment,and intelligent robots are reviewed.In addition,several novel properties of skin-inspired physical sensors such as versatility,self-healability,and implantability are introduced.Finally,the existing challenges and future perspectives of physical sensors for practical applications are discussed and proposed.
基金This work was financially supported by the National Natural Science Foundation of China(21975141 and 52125201)the National Key Basic Research and Development Program(2020YFA0210702).
文摘Silkworm silk fbers have been woven into textiles for thousands of years,because of their attractive luster,good mechanical properties,excellent biocompatibility,and large-scale production.With the development of human society,preparation of silk fbers with modifed or enhanced properties are highly desirable for potential applications in structural materials and smart textiles.Herein,we realized the reinforcement of multiple properties of silk fbers by feeding silkworms with Ag nanowire(Ag NW)modifed diets.The obtained silk fbers show obviously enhanced comprehensive mechanical properties,including improved tensile strength,elongation at break,tensile modulus,and toughness,which are increased by 37.2%,37.6%,68.3%,and 69.8%,respectively.Furthermore,compared with unmodifed silk,the electrical conductivity and thermal conductivity of modifed silk fbers are improved by 246.4%and 32.1%,respectively.The analysis on the components and structure shows that the incorporated Ag NWs lead to increased content of random coil/α-helix,improved orientation of crystallites,and increased content of Ag compared to pristine silk fbers,which may contribute to the enhanced mechanical,electrical,and thermal properties.
基金This work was supported by the NSF of China(51672153,51422204,21975141)the National Key Basic Research and Development Program(No.2016YFA0200103)the National Program for Support of Top-notch Young Professionals.
文摘Smart textiles are attracting great interest.Particularly,air-conditioning textiles are highly desired for their merits in energy conservation and personal temperature/humidity management.Currently,air-conditioning textiles can be fabricated by two strategies.One uses infrared-radiation-adaptive materials,and the other uses moisture-responsive actuators that can regulate temperature and humidity simultaneously.Here,the fabrication of a silk-yarn switch comprising electrospun highly aligned nanofibers is reported and its application in air-conditioning textiles is demonstrated.Silk yarn rotates in contact with liquid,and can be recovered by drying.The different responses and wetting behaviors of the switch to H_(2)O and C_(2)H_(6)O is investigated.It is argued that alignment and surface hydrophilicity of nanofibers play important roles in this term.To elaborate,actuating trait is mainly controlled by reduction of the surface free energy of aligned silk nanofibers,during the wetting process.As proof of concept,the application of the sweat-driven silk-yarn switch in regulating the temperature/humidity of the human body is demonstrated in this work.Considering the large production,versatile processibility,and good biocompatibility,silk actuator may have practical applications in designing smart switches(or valves)for intelligent textiles,artificial muscles,and other application scenarios.
基金the National Natural Science Foundation of China(52125201 and 21975141)the National Key Basic Research and Development Program(2020YFA0210702).
文摘Silkworm silk,which is obtained from domesticated Bombyx mori(B.mori),can be produced in a large scale.However,the mechanical properties of silkworm silk are inferior to its counterpart,spider dragline silk.Therefore,researchers are continuously exploring approaches to reinforce silkworm silk.Herein,we report a facile and scalable hot stretching process to reinforce natural silk fibers obtained from silkworm cocoons.Experimental results show that the obtained hot-stretched silk fibers(HSSFs)retain the chemical components of the original silk fibers while being endowed with increasedβ-sheet nanocrystal content and crystalline orientation,leading to enhanced mechanical properties.Significantly,the average modulus of the HSSFs reaches 21:6±2:8 GPa,which is about twice that of pristine silkworm silk fibers(11:0±1:7 GPa).Besides,the tensile strength of the HSSFs reaches 0:77±0:13 GPa,which is also obviously higher than that of the pristine silk(0:56±0:08 GPa).The results show that the hot stretching treatment is effective and efficient for producing superstiff,strong,and tough silkworm silk fibers.We anticipate this approach may be also effective for reinforcing other natural or artificial polymer fibers or films containing abundant hydrogen bonds.
基金the National Key Technology R&D Program of China(No.2020YFA0210702)the National Natural Science Foundation of China(No.21975141).
文摘Carbon nanotubes(CNTs)hold great promise in many fields because of their unique structures and properties.However,the preparation of CNTs generally involves cumbersome equipment and time-consuming processes.Here,we report an ultra-fast carbothermal shock(CTS)approach for synthesizing CNTs with a simple homemade setup by employing Joule heating of a carbon substrate.Carbonized silk fabric(CSF)loaded with transition metal salts in ethanol solution was used as the substrate,which was treated with a pulse voltage of 40 V for only 50 ms and then covered with uniform CNTs grown with bimetallic alloy catalyst nanoparticles(diameter:~9 nm).The temperature ramp rate is as high as 105 K/s.The as-obtained sample has a unique fluffy structure similar to the trichobothrium of spiders,endowing it versatile applications such as airflow sensors or air filters.The CTS technique presents an easy-accessible and highly efficient approach for synthesizing CNTs,which may be also applied in synthesizing other nanomaterials.