Stretchable energy storage devices,maintaining the capability of steady operation under large mechanical strain,have become increasing more important with the development of stretchable electronic devices.Stretchable ...Stretchable energy storage devices,maintaining the capability of steady operation under large mechanical strain,have become increasing more important with the development of stretchable electronic devices.Stretchable supercapacitors(SSCs),with high power density,modest energy density,and superior mechanical properties are regarded as one of the most promising power supplies to stretchable electronic devices.Conductive polymers,such as polyaniline(PANI),polypyrrole(PPy),polythiophene(PTh)and poly(3,4-ehtylenedioxythiophene)(PEDOT),are among the well-studied electroactive materials for the construction of SSCs because of their high specific theoretical capacity,excellent electrochemical activity,light weight,and high flexibility.Much effort has been devoted to developing stretchable,conductive polymer-based SSCs with different device structures,such as sandwich-type and fiber-shaped type SSCs.This review summarizes the material and structural design for con ductive polymer-based SSCs and discusses the challenge and importa nt di recti ons in this emergi ng field.展开更多
Continuous deforming always leads to the performance degradation of a flexible triboelectric nanogenerator due to the Young’s modulus mismatch of different functional layers.In this work,we fabricated a fiber-shaped ...Continuous deforming always leads to the performance degradation of a flexible triboelectric nanogenerator due to the Young’s modulus mismatch of different functional layers.In this work,we fabricated a fiber-shaped stretchable and tailorable triboelectric nanogenerator(FST-TENG)based on the geometric construction of a steel wire as electrode and ingenious selection of silicone rubber as triboelectric layer.Owing to the great robustness and continuous conductivity,the FST-TENGs demonstrate high stability,stretchability,and even tailorability.For a single device with ~6 cm in length and ~3 mm in diameter,the open-circuit voltage of ~59.7 V,transferred charge of ~23.7 nC,short-circuit current of ~2.67 μA and average power of ~2.13 μW can be obtained at 2.5 Hz.By knitting several FST-TENGs to be a fabric or a bracelet,it enables to harvest human motion energy and then to drive a wearable electronic device.Finally,it can also be woven on dorsum of glove to monitor the movements of gesture,which can recognize every single finger,different bending angle,and numbers of bent finger by analyzing voltage signals.展开更多
Stretchable and conformal humidity sensors that can be attached to the human body for continuously monitoring the humidity of the environment around the human body or the moisture level of the human skin can play an i...Stretchable and conformal humidity sensors that can be attached to the human body for continuously monitoring the humidity of the environment around the human body or the moisture level of the human skin can play an important role in electronic skin and personal healthcare applications. However, most stretchable humidity sensors are based on the geometric engineering of non-stretchable components and only a few detailed studies are available on stretchable humidity sensors under applied mechanical deformations. In this paper, we propose a transparent, stretchable humidity sensor with a simple fabrication process, having intrinsically stretchable components that provide high stretchability, sensitivity, and stability along with fast response and relaxation time. Composed of reduced graphene oxide-polyurethane composites and an elastomeric conductive electrode, this device exhibits impressive response and relaxation time as fast as 3.5 and 7 s, respectively. The responsivity and the response and relaxation time of the device in the presence of humidity remain almost unchanged under stretching up to a strain of 60% and after 10,000 stretching cycles at a 40% strain. Further, these stretchable humidity sensors can be easily and conformally attached to a finger for monitoring the humidity levels of the environment around the human body, wet objects, or human skin.展开更多
Conductive hydrogels have potential applications in shielding electromagnetic(EM)radiation interference in deformable and wearable electronic devices,but usually suffer from poor environmental stability and stretching...Conductive hydrogels have potential applications in shielding electromagnetic(EM)radiation interference in deformable and wearable electronic devices,but usually suffer from poor environmental stability and stretching-induced shielding performance degradation.Although organohydrogels can improve the environmental stability of materials,their development is at the expense of reducing electrical conductivity and thus weakening EM interference shielding ability.Here,a MXene organohydrogel is prepared which is composed of MXene network for electron conduction,binary solvent channels for ion conduction,and abundant solvent-polymer-MXene interfaces for EM wave scattering.This organohydrogel possesses excellent anti-drying ability,low-temperature tolerance,stretchability,shape adaptability,adhesion and rapid self-healing ability.Two effective strategies have been proposed to solve the problems of current organohydrogel shielding materials.By reasonably controlling the MXene content and the glycerol-water ratio in the gel,MXene organohydrogel can exhibit exceptionally enhanced EM interference shielding performances compared to MXene hydrogel due to the increased physical cross-linking density of the gel.Moreover,MXene organohydrogel shows attractive stretching-enhanced interference effectiveness,caused by the connection and parallel arrangement of MXene nanosheets.This well-designed MXene organohydrogel has potential applications in shielding EM interference in deformable and wearable electronic devices.展开更多
Copper nanowires （Cu NWs） have attracted increasing attention as building blocks for electronics due to their outstanding electrical properties and low cost. However, organic residues and oxide layers ubiquitously e...Copper nanowires （Cu NWs） have attracted increasing attention as building blocks for electronics due to their outstanding electrical properties and low cost. However, organic residues and oxide layers ubiquitously existing on the surface of Cu NWs impede good inter-wire contact. Commonly used methods such as thermal annealing and acid treatment often lead to nanowire damage. Herein, hydrogen plasma treatment at room temperature has been demonstrated to be effective for simultaneous surface cleaning and selective welding of Cu NWs at junctions. Transparent electrodes with excellent optical-electrical performance （19 ff）-sq-1 @ 90% T） and enhanced stability have been fabricated and integrated into organic solar cells. Besides, Cu NW conductors with superior stretchability and cycling stability under stretching speeds of up to 400 mm-min-＇ can also be produced by the nanowelding process, and the feasibility of their application in stretchable LED circuits has been demonstrated.展开更多
Stretchable electronic sensing devices are defining the path toward wearable electronics. High-performance flexible strain sensors attached on clothing or human skin are required for potential applications in the ente...Stretchable electronic sensing devices are defining the path toward wearable electronics. High-performance flexible strain sensors attached on clothing or human skin are required for potential applications in the entertainment,health monitoring, and medical care sectors. In this work,conducting copper electrodes were fabricated onpolydimethylsiloxane as sensitive stretchable microsensors by integrating laser direct writing and transfer printing approaches. The copper electrode was reduced from copper salt using laser writing rather than the general approach of printing with pre-synthesized copper or copper oxide nanoparticles. An electrical resistivity of 96 l X cm was achieved on 40-lm-thick Cu electrodes on flexible substrates. The motion sensing functionality successfully demonstrated a high sensitivity and mechanical robustness.This in situ fabrication method leads to a path toward electronic devices on flexible substrates.展开更多
Silver nanowires （AgNWs） have emerged as a promising nanomaterial for next generation stretchable electronics. However, until now, the fabrication of AgNW- based components has been hampered by complex and time-cons...Silver nanowires （AgNWs） have emerged as a promising nanomaterial for next generation stretchable electronics. However, until now, the fabrication of AgNW- based components has been hampered by complex and time-consuming steps. Here, we introduce a facile, fast, and one-step methodology for the fabrication of highly conductive and stretchable AgNW/polyurethane （PU） composite electrodes based on a high-intensity pulsed light （HIPL） technique. HIPL simultaneously improved wire-wire junction conductivity and wire-substrate adhesion at room temperature and in air within 50 μs, omitting the complex transfer-curing-implanting process. Owing to the localized deformation of PU at interfaces with AgNWs, embedding of the nanowires was rapidly carried out without substantial substrate damage. The resulting electrode retained a low sheet resistance （high electrical conductivity） of 〈10 Ω/sq even under 100% strain, or after 1,000 continuous stretching-relaxation cycles, with a peak strain of 60%. The fabricated electrode has found immediate application as a sensor for motion detection. Furthermore, based on our electrode, a light emitting diode （LED） driven by integrated stretchable AgNW conductors has been fabricated. In conclusion, our present fabrication approach is fast, simple, scalable, and cost- efficient, making it a good candidate for a future roll-to-roll process.展开更多
The urgent demand for portable electronics has promoted the development of high-efficienc）9 sustainable, and even stretchable self-charging power sources. In this work, we propose a flexible self-charging power unit ...The urgent demand for portable electronics has promoted the development of high-efficienc）9 sustainable, and even stretchable self-charging power sources. In this work, we propose a flexible self-charging power unit based on folded carbon （FC） paper for harvesting mechanical energy from human motion and power portable electronics. The present unit mainly consists of a triboelectric nanogenerator （FC-TENG） and a supercapacitor （FC-SC）, both based on folded carbon paper, as energy harvester and storage device, respectively. This favorable geometric design provides the high Young＇s modulus carbon paper with excellent stretchability and enables the power unit to work even under severe deformations, such as bending, twisting, and rolling. In addition, the tensile strain can be maximized by tuning the folding angle of the triangle-folded carbon paper. Moreover, the waterproof property of the packaged device make it washable, protect it from human sweat, and enable it to work in harsh environments. Finally, the as-prepared self-charging power unit was tested by placing it on the human body to harvest mechanical energy from hand tapping, foot treading, and arm touching, successfully powering an electronic watch. This work demonstrates the impressive potential of stretchable self-charging power units, which will further promote the development of high Young＇s modulus materials for wearable/portable electronics.展开更多
With the advent of the 5G era and the rise of the Internet of Things,various sensors have received unprecedented attention,especially wearable and stretchable sensors in the healthcare field.Here,a stretchable,self-he...With the advent of the 5G era and the rise of the Internet of Things,various sensors have received unprecedented attention,especially wearable and stretchable sensors in the healthcare field.Here,a stretchable,self-healable,self-adhesive,and room-temperature oxygen sensor with excellent repeatability,a full concentration detection range(0-100%),low theoretical limit of detection(5.7 ppm),high sensitivity(0.2%/ppm),good linearity,excellent temperature,and humidity tolerances is fabricated by using polyacrylamide-chitosan(PAM-CS)double network(DN)organohydrogel as a novel transducing material.The PAM-CS DN organohydrogel is transformed from the PAM-CS composite hydrogel using a facile soaking and solvent replacement strategy.Compared with the pristine hydrogel,the DN organohydrogel displays greatly enhanced mechanical strength,moisture retention,freezing resistance,and sensitivity to oxygen.Notably,applying the tensile strain improves both the sensitivity and response speed of the organohydrogel-based oxygen sensor.Furthermore,the response to the same concentration of oxygen before and after self-healing is basically the same.Importantly,we propose an electrochemical reaction mechanism to explain the positive current shift of the oxygen sensor and corroborate this sensing mechanism through rationally designed experiments.The organohydrogel oxygen sensor is used to monitor human respiration in real-time,verifying the feasibility of its practical application.This work provides ideas for fabricating more stretchable,self-healable,self-adhesive,and high-performance gas sensors using ion-conducting organohydrogels.展开更多
Flexible strain sensors exhibit outstanding advantages in terms of sensitivity and stability by detecting changes in physical signals.It can be easily attached to human skin and clothed to achieve monitoring of human ...Flexible strain sensors exhibit outstanding advantages in terms of sensitivity and stability by detecting changes in physical signals.It can be easily attached to human skin and clothed to achieve monitoring of human motion and health.However,general sensing material shows low stretchability and cannot respond to signals under large deformation.In this work,a highly stretchable polymer composite was developed by adding small amount(0.17 wt.%)of silver nanowires(AgNWs)in stretchable conductive polymer materials.The conductivity of polymer/AgNWs composite is 1.3 S/m with the stretchability up to 500%.The stretchable strain sensor based on the polymer/AgNWs composite can respond to strain signals in real time,even for 1%strain response,and shows excellent stability over 1,000 loading/unloading cycles.Moreover,the strain sensor can be attached to human skin and clothed to monitor joints,throat and pulse of the human body.The human body electrocardiogram(ECG)signal was detected successfully with the polymer/AgNWs electrode,which is comparable to the signal obtained by the commercial electrode.Overall,the sensors enable monitoring of human movement and health.These advantages make it a potential application in wearable devices and electronic skin.展开更多
The rapid increase in the aging population prompts the development of wearable devices and sophisticated robots. With their ability to collect complex information about their surroundings via e-skins, robots could per...The rapid increase in the aging population prompts the development of wearable devices and sophisticated robots. With their ability to collect complex information about their surroundings via e-skins, robots could perform more dynamic and variable tasks such as rescue missions or caring for the elderly. In this paper, we present a new concept of utilizing a very simple, highly flexible and stretchable capacitor sensor array, that can be attached on the surface of a retractable robot hand to realize three functions: determining the location, shape, and pressure of an object. This adaptive sensing system is accomplished using capacitors connected by aligned carbon nanotube(CNT) films constructed on an elastomer dielectric material, which can reduce the requirement on the accuracy of the machine vision system. This study has a very broad application in the manufacture of intelligent software robots.展开更多
Screen sensors are the most commonly used human-machine interfaces in our everyday life,which have been extensively applied in personal electronics like cellphones.Touchless screen sensors are attracting growing inter...Screen sensors are the most commonly used human-machine interfaces in our everyday life,which have been extensively applied in personal electronics like cellphones.Touchless screen sensors are attracting growing interest due to their distinct advantages of high interaction freedom,comfortability,and hand hygiene.However,the material compositions of current touchless screen sensors are rigid and fragile,hardly meeting the needs of wearable and stretchable on-skin electronics development.Additionally,these touchless screen sensors are also restricted by high power consumption,limited gesture types of recognition,and the requirement of light conditions.Here,we report a stretchable on-skin touchless screen sensor(OTSS)enabled by an ionic hydrogel-based triboelectric nanogenerator(TENG).Compared with current touchless screen sensors,the OTSS is stretchable,self-powered,and competent to recognize diverse gestures by making use of charges naturally carried on fingers without the need of sufficient light conditions.An on-skin noncontact screen operating system is further demonstrated on the basis of the OTSS,which could unlock a cellphone interface in touchless operation mode on the human skin.This work for the first time introduces the on-skin touchless concept to screen sensors and offers a direction to develop new-generation screen sensors for future cellphones and personal electronics.展开更多
There has been ongoing keen interest to mold electronic devices into desired shapes and be laid on desired configurable surfaces. In specific, the ability to design materials that can bend, twist, compress and stretch...There has been ongoing keen interest to mold electronic devices into desired shapes and be laid on desired configurable surfaces. In specific, the ability to design materials that can bend, twist, compress and stretch repeatedly, while still able to maintain its full capability as conductors or electrodes, has led to numerous efforts to develop flexible and stretchable (bio)devices that are both technologically challenging and environmentally friendly (e.g. biodegradable). In this review, we highlight several recent significant results that have made impacts toward the field of flexible and stretchable electronics, sensors and power sources.展开更多
As a stretchable seamless device,electronic skin(E-skin)has drawn enormous interest due to its skin-like sensing capability.Besides the basic perception of force and temperature,multiple perception that is beyond exis...As a stretchable seamless device,electronic skin(E-skin)has drawn enormous interest due to its skin-like sensing capability.Besides the basic perception of force and temperature,multiple perception that is beyond existing functions of human skin is becoming an important direction for E-skin developments.However,the present E-skins for multiple perceptions mainly rely on different sensing materials and heterogeneous integration,resulting in a complex device structure.Additionally,their stretchability is usually achieved by the complicated microstructure design of rigid materials.Here,we report an intrinsically stretchable polymer semiconductor based E-skin with a simple structure for multiple perceptions of force,temperature,and visible light.The E-skin is on the basis of poly(3-hexylthiophene)(P3HT)nanofibers percolated polydimethylsiloxane(PDMS)composite polymer semiconductor,which is fabricated by a facile solution method.The E-skin shows reliable sensing capabilities when it is used to perceive strain,pressure,temperature,and visible light.Based on the E-skin,an intelligent robotic hand sensing and controlling system is further demonstrated.Compared with conventional E-skins for multiple perceptions,this E-skin only has a simple monolayer sensing membrane without the need of combining different sensing materials,heterogeneous integration,and complicated microstructure design.Such a strategy of utilizing intrinsically stretchable polymer semiconductor to create simple structured E-skin for multiple perceptions will promote the development of E-skins in a broad application scenario,such as artificial robotic skins,virtual reality,intelligent gloves,and biointegrated electronics.展开更多
The remarkable ability of biological systems to sense and adapt to complex environmental conditions has inspired the design of next-generation electronics with advanced functionalities.This review focuses on emerging ...The remarkable ability of biological systems to sense and adapt to complex environmental conditions has inspired the design of next-generation electronics with advanced functionalities.This review focuses on emerging bio-inspired strategies for the development of flexible and stretchable electronics that can accommodate mechanical deformations and integrate seamlessly with biological systems.We will provide an overview of the practical considerations in the materials and structure designs of flexible and stretchable electronics.Recent progress in bio-inspired pressure/strain sensors,stretchable electrodes,mesh electronics,and flexible energy devices are then discussed,with an emphasis on their unconventional micro/nanostructure designs and advanced functionalities.Finally,current challenges and future perspectives are identified and discussed.展开更多
Transparent conductive electrodes play a significant role in the fabrication and development of optoelectronic devices. As next generation optoelectronic devices tend towards mobile and wearable devices, the added att...Transparent conductive electrodes play a significant role in the fabrication and development of optoelectronic devices. As next generation optoelectronic devices tend towards mobile and wearable devices, the added attribute of flexibility or stretchability for these electrodes becomes increasingly important. However, mechanical requirements aside, transparent conductive electrodes must still retain high transparency and conductivity, with the metrics for these parameters being compared to the standard, indium tin oxide. In the search to replace indium tin oxide, two materials that have risen to the forefront are carbon nanotubes and silver nanowires due to their high transparency, conductivity, mechanical compliance, and ease of fabrication. This review highlights recent innovations made by our group in electrodes utilizing carbon nanotubes and silver nanowires, in addition to the use of these electrodes in discrete devices and integrated systems.展开更多
Respiratory monitoring plays a pivotal role in health assessment and provides an important application prospect for flexible humidity sensors.However,traditional humidity sensors suffer from a trade-off between deform...Respiratory monitoring plays a pivotal role in health assessment and provides an important application prospect for flexible humidity sensors.However,traditional humidity sensors suffer from a trade-off between deformability,sensitivity,and transparency,and thus the development of high-performance,stretchable,and low-cost humidity sensors is urgently needed as wearable electronics.Here,ultrasensitive,highly deformable,and transparent humidity sensors are fabricated based on cost-effective polyacrylamide-based double network hydrogels.Concomitantly,a general method for preparing hydrogel films with controllable thickness is proposed to boost the sensitivity of hydrogel-based sensors due to the extensively increased specific surface area,which can be applied to different polymer networks and facilitate the development of flexible integrated electronics.In addition,sustainable tapioca rich in hydrophilic polar groups is introduced for the first time as a second cross-linked network,exhibiting excellent water adsorption capacity.Through the synergistic optimization of structure and composition,the obtained hydrogel film exhibits an ultrahigh sensitivity of 13,462.1%/%RH,which is unprecedented.Moreover,the hydrogel film-based sensor exhibits excellent repeatability and the ability to work normally under stretching with even enhanced sensitivity.As a proof of concept,we integrate the stretchable sensor with a specially designed wireless circuit and mask to fabricate a wireless respiratory interruption detection system with Bluetooth transmission,enabling real-time monitoring of human health status.This work provides a general strategy to construct high-performance,stretchable,and miniaturized hydrogel-based sensors as next-generation wearable devices for real-time monitoring of various physiological signals.展开更多
Stretchable electronics that monitor joint activity and treat diseases based on liquid metal could be used in the development of healthcare applications.Such devices can be seamlessly integrated with human skin.Howeve...Stretchable electronics that monitor joint activity and treat diseases based on liquid metal could be used in the development of healthcare applications.Such devices can be seamlessly integrated with human skin.However,most high-precision microstructures and complex patterns are difficult to fabricate due to the limitations of conventional fabrication solutions,resulting in suboptimal performance under practical conditions.Here,a liquid-metal stretchable system utilizing natural leaf veins was reported as microstructures,which was based on a biomimetic concept and utilized an all-solution process for the preparation of complex microstructures.The systems are ultra-high tensile(800%tensile strain),environmentally stable(20 days)and mechanically durable(300-cycle).The system can accurately recognize the wearer's finger bending level as well as simple gesture signals.At the same time,the system acts as a wearable heater,which can realize the fast heating behavior of heating up to 50℃in 3 min under the human body-safe voltage(1.5 V).The tensile stability is demonstrated by the heterogeneous integration of lasers(405 nm)with the system interconnects for a stretchable and wearable light source.展开更多
Stretchable power sources,especially stretchable lithium-ion batteries(LIBs),have attracted increasing attention due to their enormous prospects for powering flexible/wearable electronics.Despite recent advances,it is...Stretchable power sources,especially stretchable lithium-ion batteries(LIBs),have attracted increasing attention due to their enormous prospects for powering flexible/wearable electronics.Despite recent advances,it is still challenging to develop ultra-stretchable LIBs that can withstand large deformation.In particular,stretchable LIBs require an elastic electrolyte as a basic component,while the conductivity of most elastic electrolytes drops sharply during deformation,especially during large deformations.This is why highly stretchable LIBs have not yet been realized until now.As a proof of concept,a super-stretchable LIB with strain up to 1200%is created based on an intrinsically super-stretchable polymer electrolyte as the lithium-ion conductor.The super-stretchable conductive system is constructed by an effective diblock copolymerization strategy via photocuring of vinyl functionalized 2-ureido-4-pyrimidone(VFUpy),an acrylic monomer containing succinonitrile and a lithium salt,achieving high ionic conductivity(3.5×10^(-4)mS cm^(-1)at room temperature(RT))and large deformation(the strain can reach 4560%).The acrylic elastomer containing Li-ion conductive domains can strongly increase the compatibility between the neighboring elastic networks,resulting in high ionic conductivity under ultra-large deformation,while VFUpy increases elasticity modulus(over three times)and electrochemical stability(voltage window reaches 5.3 V)of the prepared polymer conductor.At a strain of up to 1200%,the resulting stretchable LIBs are still sufficient to power LEDs.This study sheds light on the design and development of high-performance intrinsically super-stretchable materials for the advancement of highly elastic energy storage devices for powering flexible/wearable electronics that can endure large deformation.展开更多
文摘Stretchable energy storage devices,maintaining the capability of steady operation under large mechanical strain,have become increasing more important with the development of stretchable electronic devices.Stretchable supercapacitors(SSCs),with high power density,modest energy density,and superior mechanical properties are regarded as one of the most promising power supplies to stretchable electronic devices.Conductive polymers,such as polyaniline(PANI),polypyrrole(PPy),polythiophene(PTh)and poly(3,4-ehtylenedioxythiophene)(PEDOT),are among the well-studied electroactive materials for the construction of SSCs because of their high specific theoretical capacity,excellent electrochemical activity,light weight,and high flexibility.Much effort has been devoted to developing stretchable,conductive polymer-based SSCs with different device structures,such as sandwich-type and fiber-shaped type SSCs.This review summarizes the material and structural design for con ductive polymer-based SSCs and discusses the challenge and importa nt di recti ons in this emergi ng field.
基金supported by National Natural Science Foundation of China (NSFC) (No. 61804103)National Key R&D Program of China (No. 2017YFA0205002)+8 种基金Natural Science Foundation of the Jiangsu Higher Education Institutions of China (Nos. 18KJA535001 and 14KJB 150020)Natural Science Foundation of Jiangsu Province of China (Nos. BK20170343 and BK20180242)China Postdoctoral Science Foundation (No. 2017M610346)State Key Laboratory of Silicon Materials, Zhejiang University (No. SKL2018-03)Nantong Municipal Science and Technology Program (No. GY12017001)Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University (KSL201803)supported by Collaborative Innovation Center of Suzhou Nano Science & Technology, the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the 111 ProjectJoint International Research Laboratory of Carbon-Based Functional Materials and Devices
文摘Continuous deforming always leads to the performance degradation of a flexible triboelectric nanogenerator due to the Young’s modulus mismatch of different functional layers.In this work,we fabricated a fiber-shaped stretchable and tailorable triboelectric nanogenerator(FST-TENG)based on the geometric construction of a steel wire as electrode and ingenious selection of silicone rubber as triboelectric layer.Owing to the great robustness and continuous conductivity,the FST-TENGs demonstrate high stability,stretchability,and even tailorability.For a single device with ~6 cm in length and ~3 mm in diameter,the open-circuit voltage of ~59.7 V,transferred charge of ~23.7 nC,short-circuit current of ~2.67 μA and average power of ~2.13 μW can be obtained at 2.5 Hz.By knitting several FST-TENGs to be a fabric or a bracelet,it enables to harvest human motion energy and then to drive a wearable electronic device.Finally,it can also be woven on dorsum of glove to monitor the movements of gesture,which can recognize every single finger,different bending angle,and numbers of bent finger by analyzing voltage signals.
文摘Stretchable and conformal humidity sensors that can be attached to the human body for continuously monitoring the humidity of the environment around the human body or the moisture level of the human skin can play an important role in electronic skin and personal healthcare applications. However, most stretchable humidity sensors are based on the geometric engineering of non-stretchable components and only a few detailed studies are available on stretchable humidity sensors under applied mechanical deformations. In this paper, we propose a transparent, stretchable humidity sensor with a simple fabrication process, having intrinsically stretchable components that provide high stretchability, sensitivity, and stability along with fast response and relaxation time. Composed of reduced graphene oxide-polyurethane composites and an elastomeric conductive electrode, this device exhibits impressive response and relaxation time as fast as 3.5 and 7 s, respectively. The responsivity and the response and relaxation time of the device in the presence of humidity remain almost unchanged under stretching up to a strain of 60% and after 10,000 stretching cycles at a 40% strain. Further, these stretchable humidity sensors can be easily and conformally attached to a finger for monitoring the humidity levels of the environment around the human body, wet objects, or human skin.
基金This work was financially supported by Beijing Natural Science Foundation(2212033)National Natural Science Foundation of China(51971008,U1832138,51731002 and 51671010)+1 种基金the Fundamental Research Funds for the Central UniversitiesOpen access funding provided by Shanghai Jiao Tong University
文摘Conductive hydrogels have potential applications in shielding electromagnetic(EM)radiation interference in deformable and wearable electronic devices,but usually suffer from poor environmental stability and stretching-induced shielding performance degradation.Although organohydrogels can improve the environmental stability of materials,their development is at the expense of reducing electrical conductivity and thus weakening EM interference shielding ability.Here,a MXene organohydrogel is prepared which is composed of MXene network for electron conduction,binary solvent channels for ion conduction,and abundant solvent-polymer-MXene interfaces for EM wave scattering.This organohydrogel possesses excellent anti-drying ability,low-temperature tolerance,stretchability,shape adaptability,adhesion and rapid self-healing ability.Two effective strategies have been proposed to solve the problems of current organohydrogel shielding materials.By reasonably controlling the MXene content and the glycerol-water ratio in the gel,MXene organohydrogel can exhibit exceptionally enhanced EM interference shielding performances compared to MXene hydrogel due to the increased physical cross-linking density of the gel.Moreover,MXene organohydrogel shows attractive stretching-enhanced interference effectiveness,caused by the connection and parallel arrangement of MXene nanosheets.This well-designed MXene organohydrogel has potential applications in shielding EM interference in deformable and wearable electronic devices.
基金This work was financially supported by the National Basic Research Program of China （No. 2012CB932303）, the National Natural Science Foundation of China （No. 61301036）, Shanghai Municipal Natural Science Foundation （No. 13ZR1463600）, and the Innovation Project of Shanghai Institute of Ceramics.
文摘Copper nanowires （Cu NWs） have attracted increasing attention as building blocks for electronics due to their outstanding electrical properties and low cost. However, organic residues and oxide layers ubiquitously existing on the surface of Cu NWs impede good inter-wire contact. Commonly used methods such as thermal annealing and acid treatment often lead to nanowire damage. Herein, hydrogen plasma treatment at room temperature has been demonstrated to be effective for simultaneous surface cleaning and selective welding of Cu NWs at junctions. Transparent electrodes with excellent optical-electrical performance （19 ff）-sq-1 @ 90% T） and enhanced stability have been fabricated and integrated into organic solar cells. Besides, Cu NW conductors with superior stretchability and cycling stability under stretching speeds of up to 400 mm-min-＇ can also be produced by the nanowelding process, and the feasibility of their application in stretchable LED circuits has been demonstrated.
基金supported by National Natural Science Foundation of China (51575016)the Beijing Oversea High-Level Talent Project+1 种基金strategic research Grant (KZ20141000500, B-type) of Beijing Natural Science Foundation P.R. Chinathe support by the China Scholarship Council (20160654015) for his research stay at the Institute of Physical and Chemical Research,Wako, Japan
文摘Stretchable electronic sensing devices are defining the path toward wearable electronics. High-performance flexible strain sensors attached on clothing or human skin are required for potential applications in the entertainment,health monitoring, and medical care sectors. In this work,conducting copper electrodes were fabricated onpolydimethylsiloxane as sensitive stretchable microsensors by integrating laser direct writing and transfer printing approaches. The copper electrode was reduced from copper salt using laser writing rather than the general approach of printing with pre-synthesized copper or copper oxide nanoparticles. An electrical resistivity of 96 l X cm was achieved on 40-lm-thick Cu electrodes on flexible substrates. The motion sensing functionality successfully demonstrated a high sensitivity and mechanical robustness.This in situ fabrication method leads to a path toward electronic devices on flexible substrates.
文摘Silver nanowires （AgNWs） have emerged as a promising nanomaterial for next generation stretchable electronics. However, until now, the fabrication of AgNW- based components has been hampered by complex and time-consuming steps. Here, we introduce a facile, fast, and one-step methodology for the fabrication of highly conductive and stretchable AgNW/polyurethane （PU） composite electrodes based on a high-intensity pulsed light （HIPL） technique. HIPL simultaneously improved wire-wire junction conductivity and wire-substrate adhesion at room temperature and in air within 50 μs, omitting the complex transfer-curing-implanting process. Owing to the localized deformation of PU at interfaces with AgNWs, embedding of the nanowires was rapidly carried out without substantial substrate damage. The resulting electrode retained a low sheet resistance （high electrical conductivity） of 〈10 Ω/sq even under 100% strain, or after 1,000 continuous stretching-relaxation cycles, with a peak strain of 60%. The fabricated electrode has found immediate application as a sensor for motion detection. Furthermore, based on our electrode, a light emitting diode （LED） driven by integrated stretchable AgNW conductors has been fabricated. In conclusion, our present fabrication approach is fast, simple, scalable, and cost- efficient, making it a good candidate for a future roll-to-roll process.
文摘The urgent demand for portable electronics has promoted the development of high-efficienc）9 sustainable, and even stretchable self-charging power sources. In this work, we propose a flexible self-charging power unit based on folded carbon （FC） paper for harvesting mechanical energy from human motion and power portable electronics. The present unit mainly consists of a triboelectric nanogenerator （FC-TENG） and a supercapacitor （FC-SC）, both based on folded carbon paper, as energy harvester and storage device, respectively. This favorable geometric design provides the high Young＇s modulus carbon paper with excellent stretchability and enables the power unit to work even under severe deformations, such as bending, twisting, and rolling. In addition, the tensile strain can be maximized by tuning the folding angle of the triangle-folded carbon paper. Moreover, the waterproof property of the packaged device make it washable, protect it from human sweat, and enable it to work in harsh environments. Finally, the as-prepared self-charging power unit was tested by placing it on the human body to harvest mechanical energy from hand tapping, foot treading, and arm touching, successfully powering an electronic watch. This work demonstrates the impressive potential of stretchable self-charging power units, which will further promote the development of high Young＇s modulus materials for wearable/portable electronics.
基金support from the National Natural Science Foundation of China(61801525)the Guangdong Basic and Applied Basic Research Foundation(2020A1515010693)+1 种基金the Guangdong Natural Science Funds Grant(2018A030313400),the Science and Technology Program of Guangzhou(201904010456)the Fundamental Research Funds for the Central Universities,Sun Yat-sen University(2021qntd09).
文摘With the advent of the 5G era and the rise of the Internet of Things,various sensors have received unprecedented attention,especially wearable and stretchable sensors in the healthcare field.Here,a stretchable,self-healable,self-adhesive,and room-temperature oxygen sensor with excellent repeatability,a full concentration detection range(0-100%),low theoretical limit of detection(5.7 ppm),high sensitivity(0.2%/ppm),good linearity,excellent temperature,and humidity tolerances is fabricated by using polyacrylamide-chitosan(PAM-CS)double network(DN)organohydrogel as a novel transducing material.The PAM-CS DN organohydrogel is transformed from the PAM-CS composite hydrogel using a facile soaking and solvent replacement strategy.Compared with the pristine hydrogel,the DN organohydrogel displays greatly enhanced mechanical strength,moisture retention,freezing resistance,and sensitivity to oxygen.Notably,applying the tensile strain improves both the sensitivity and response speed of the organohydrogel-based oxygen sensor.Furthermore,the response to the same concentration of oxygen before and after self-healing is basically the same.Importantly,we propose an electrochemical reaction mechanism to explain the positive current shift of the oxygen sensor and corroborate this sensing mechanism through rationally designed experiments.The organohydrogel oxygen sensor is used to monitor human respiration in real-time,verifying the feasibility of its practical application.This work provides ideas for fabricating more stretchable,self-healable,self-adhesive,and high-performance gas sensors using ion-conducting organohydrogels.
基金This research was financially supported by the National Natural Science Foundation of China(Nos.51673214 and 61804185)the National Key Research and Development Program of China(No.2017YFA0206600)+1 种基金the Natural Science Foundation of Hunan Province(No.2019JJ50804)the Free Exploration and Innovation Project of Central South University(No.2019zzts427).
文摘Flexible strain sensors exhibit outstanding advantages in terms of sensitivity and stability by detecting changes in physical signals.It can be easily attached to human skin and clothed to achieve monitoring of human motion and health.However,general sensing material shows low stretchability and cannot respond to signals under large deformation.In this work,a highly stretchable polymer composite was developed by adding small amount(0.17 wt.%)of silver nanowires(AgNWs)in stretchable conductive polymer materials.The conductivity of polymer/AgNWs composite is 1.3 S/m with the stretchability up to 500%.The stretchable strain sensor based on the polymer/AgNWs composite can respond to strain signals in real time,even for 1%strain response,and shows excellent stability over 1,000 loading/unloading cycles.Moreover,the strain sensor can be attached to human skin and clothed to monitor joints,throat and pulse of the human body.The human body electrocardiogram(ECG)signal was detected successfully with the polymer/AgNWs electrode,which is comparable to the signal obtained by the commercial electrode.Overall,the sensors enable monitoring of human movement and health.These advantages make it a potential application in wearable devices and electronic skin.
基金supported by the National Key Research and Development Program of China(Grant No.2017YFB0307000-01)the National Natural Science Foundation of China(Grant No.91648109)the Priority Academic Program Development of Jiangsu Higher Education Institutions,333 Project of Jiangsu Province
文摘The rapid increase in the aging population prompts the development of wearable devices and sophisticated robots. With their ability to collect complex information about their surroundings via e-skins, robots could perform more dynamic and variable tasks such as rescue missions or caring for the elderly. In this paper, we present a new concept of utilizing a very simple, highly flexible and stretchable capacitor sensor array, that can be attached on the surface of a retractable robot hand to realize three functions: determining the location, shape, and pressure of an object. This adaptive sensing system is accomplished using capacitors connected by aligned carbon nanotube(CNT) films constructed on an elastomer dielectric material, which can reduce the requirement on the accuracy of the machine vision system. This study has a very broad application in the manufacture of intelligent software robots.
基金supported by the National Natural Science Foundation of China(Nos.62074137,52303112)the Foundation for Outstanding Young Teachers in Universities of Henan Province(No.2021GGJS014)the China Postdoctoral Science Foundation(Nos.2022TQ0281,2023M733213).
文摘Screen sensors are the most commonly used human-machine interfaces in our everyday life,which have been extensively applied in personal electronics like cellphones.Touchless screen sensors are attracting growing interest due to their distinct advantages of high interaction freedom,comfortability,and hand hygiene.However,the material compositions of current touchless screen sensors are rigid and fragile,hardly meeting the needs of wearable and stretchable on-skin electronics development.Additionally,these touchless screen sensors are also restricted by high power consumption,limited gesture types of recognition,and the requirement of light conditions.Here,we report a stretchable on-skin touchless screen sensor(OTSS)enabled by an ionic hydrogel-based triboelectric nanogenerator(TENG).Compared with current touchless screen sensors,the OTSS is stretchable,self-powered,and competent to recognize diverse gestures by making use of charges naturally carried on fingers without the need of sufficient light conditions.An on-skin noncontact screen operating system is further demonstrated on the basis of the OTSS,which could unlock a cellphone interface in touchless operation mode on the human skin.This work for the first time introduces the on-skin touchless concept to screen sensors and offers a direction to develop new-generation screen sensors for future cellphones and personal electronics.
基金funding from the Bill and Melinda Gates Foundation Grand Challenge Award (OPP1032970)
文摘There has been ongoing keen interest to mold electronic devices into desired shapes and be laid on desired configurable surfaces. In specific, the ability to design materials that can bend, twist, compress and stretch repeatedly, while still able to maintain its full capability as conductors or electrodes, has led to numerous efforts to develop flexible and stretchable (bio)devices that are both technologically challenging and environmentally friendly (e.g. biodegradable). In this review, we highlight several recent significant results that have made impacts toward the field of flexible and stretchable electronics, sensors and power sources.
基金the financial support from the National Key Research and Development Program of China (2023YFB3608904)the National Natural Science Foundation of China (21835003)+4 种基金the Natural Science Research Start-Up Foundation of Recruiting Talents of Nanjing University of Posts and Telecommunications (NY222103)the Natural Science Foundation of Jiangsu Province (BE2019120)the Foundation of Key Laboratory of Flexible Electronics of Zhejiang Province (2023FE002)the Program for Jiangsu Specially-Appointed Professor (RK030STP15001)the Leading Talent of Technological Innovation of National Ten-Thousands Talents Program of China
基金This work was supported by the National Natural Science Foundation of China(No.62074137)the Key Research,Development,and Promotion Program of Henan Province(No.202102210004)China Postdoctoral Science Foundation(No.2021TQ0288).
文摘As a stretchable seamless device,electronic skin(E-skin)has drawn enormous interest due to its skin-like sensing capability.Besides the basic perception of force and temperature,multiple perception that is beyond existing functions of human skin is becoming an important direction for E-skin developments.However,the present E-skins for multiple perceptions mainly rely on different sensing materials and heterogeneous integration,resulting in a complex device structure.Additionally,their stretchability is usually achieved by the complicated microstructure design of rigid materials.Here,we report an intrinsically stretchable polymer semiconductor based E-skin with a simple structure for multiple perceptions of force,temperature,and visible light.The E-skin is on the basis of poly(3-hexylthiophene)(P3HT)nanofibers percolated polydimethylsiloxane(PDMS)composite polymer semiconductor,which is fabricated by a facile solution method.The E-skin shows reliable sensing capabilities when it is used to perceive strain,pressure,temperature,and visible light.Based on the E-skin,an intelligent robotic hand sensing and controlling system is further demonstrated.Compared with conventional E-skins for multiple perceptions,this E-skin only has a simple monolayer sensing membrane without the need of combining different sensing materials,heterogeneous integration,and complicated microstructure design.Such a strategy of utilizing intrinsically stretchable polymer semiconductor to create simple structured E-skin for multiple perceptions will promote the development of E-skins in a broad application scenario,such as artificial robotic skins,virtual reality,intelligent gloves,and biointegrated electronics.
基金We thank Dr.Jidong Shi from The Hong Kong Polytechnic University for helpful discussions.This work is supported by the National Natural Science Foundation of China(Nos.21790393 and 51972073)Frontier Research Program of the Chinese Academy of Sciences(No.XDB32030100).
文摘The remarkable ability of biological systems to sense and adapt to complex environmental conditions has inspired the design of next-generation electronics with advanced functionalities.This review focuses on emerging bio-inspired strategies for the development of flexible and stretchable electronics that can accommodate mechanical deformations and integrate seamlessly with biological systems.We will provide an overview of the practical considerations in the materials and structure designs of flexible and stretchable electronics.Recent progress in bio-inspired pressure/strain sensors,stretchable electrodes,mesh electronics,and flexible energy devices are then discussed,with an emphasis on their unconventional micro/nanostructure designs and advanced functionalities.Finally,current challenges and future perspectives are identified and discussed.
基金supported in part by the Air Force Office of Scientific Research (FA9550-12-1-0074, Dr. Charles Lee)
文摘Transparent conductive electrodes play a significant role in the fabrication and development of optoelectronic devices. As next generation optoelectronic devices tend towards mobile and wearable devices, the added attribute of flexibility or stretchability for these electrodes becomes increasingly important. However, mechanical requirements aside, transparent conductive electrodes must still retain high transparency and conductivity, with the metrics for these parameters being compared to the standard, indium tin oxide. In the search to replace indium tin oxide, two materials that have risen to the forefront are carbon nanotubes and silver nanowires due to their high transparency, conductivity, mechanical compliance, and ease of fabrication. This review highlights recent innovations made by our group in electrodes utilizing carbon nanotubes and silver nanowires, in addition to the use of these electrodes in discrete devices and integrated systems.
基金J.W.acknowledges financial supports from the National Natural Science Foundation of China(61801525)the Guangdong Basic and Applied Basic Research Foundation(2020A1515010693)the Fundamental Research Funds for the Central Universities,Sun Yat-sen University(22lgqb17).
文摘Respiratory monitoring plays a pivotal role in health assessment and provides an important application prospect for flexible humidity sensors.However,traditional humidity sensors suffer from a trade-off between deformability,sensitivity,and transparency,and thus the development of high-performance,stretchable,and low-cost humidity sensors is urgently needed as wearable electronics.Here,ultrasensitive,highly deformable,and transparent humidity sensors are fabricated based on cost-effective polyacrylamide-based double network hydrogels.Concomitantly,a general method for preparing hydrogel films with controllable thickness is proposed to boost the sensitivity of hydrogel-based sensors due to the extensively increased specific surface area,which can be applied to different polymer networks and facilitate the development of flexible integrated electronics.In addition,sustainable tapioca rich in hydrophilic polar groups is introduced for the first time as a second cross-linked network,exhibiting excellent water adsorption capacity.Through the synergistic optimization of structure and composition,the obtained hydrogel film exhibits an ultrahigh sensitivity of 13,462.1%/%RH,which is unprecedented.Moreover,the hydrogel film-based sensor exhibits excellent repeatability and the ability to work normally under stretching with even enhanced sensitivity.As a proof of concept,we integrate the stretchable sensor with a specially designed wireless circuit and mask to fabricate a wireless respiratory interruption detection system with Bluetooth transmission,enabling real-time monitoring of human health status.This work provides a general strategy to construct high-performance,stretchable,and miniaturized hydrogel-based sensors as next-generation wearable devices for real-time monitoring of various physiological signals.
基金financially supported by the National Key Research and Development Program of China(No.2021YFA1401100)the National Natural Science Foundation of China(Nos.61825403 and 61921005)。
文摘Stretchable electronics that monitor joint activity and treat diseases based on liquid metal could be used in the development of healthcare applications.Such devices can be seamlessly integrated with human skin.However,most high-precision microstructures and complex patterns are difficult to fabricate due to the limitations of conventional fabrication solutions,resulting in suboptimal performance under practical conditions.Here,a liquid-metal stretchable system utilizing natural leaf veins was reported as microstructures,which was based on a biomimetic concept and utilized an all-solution process for the preparation of complex microstructures.The systems are ultra-high tensile(800%tensile strain),environmentally stable(20 days)and mechanically durable(300-cycle).The system can accurately recognize the wearer's finger bending level as well as simple gesture signals.At the same time,the system acts as a wearable heater,which can realize the fast heating behavior of heating up to 50℃in 3 min under the human body-safe voltage(1.5 V).The tensile stability is demonstrated by the heterogeneous integration of lasers(405 nm)with the system interconnects for a stretchable and wearable light source.
基金We acknowledge financial support from the National Natural Science Foundation of China(21835003,21674050,91833304,21805136 and 61904084)the National Key Basic Research Program of China(2023YFB3608904,2017YFB0404501 and 2014CB648300)+8 种基金the Natural Science Foundation of Jiangsu Province(BK20210601,BE2019120 and BK20190737)Program for Jiangsu Specially-Appointed Professor(RK030STP15001)the Six Talent Peaks Project of Jiangsu Province(TD-XCL-009)the 333 Project of Jiangsu Province(BRA2017402),the NUPT"1311 Project"and Scientific Foundation(NY219159,NY218164 and NY219020)the Leading Talent of Technological Innovation of National Ten-Thousands Talents Program of China,the Excellent Scientific and Technological Innovative Teams of Jiangsu Higher Education Institutions(TJ217038)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD,YX030003)Special Fund of"Jiangsu Provincial High-level Innovative and Entrepreneurial Talents Introduction Program"(the first batch)in 2020(Doctoral Aggregation Program)(CZ030SC20016)China Postdoctoral Science Foundation(2021M691652)Jiangsu Province Postdoctoral Science Foundation(2021K323C).
文摘Stretchable power sources,especially stretchable lithium-ion batteries(LIBs),have attracted increasing attention due to their enormous prospects for powering flexible/wearable electronics.Despite recent advances,it is still challenging to develop ultra-stretchable LIBs that can withstand large deformation.In particular,stretchable LIBs require an elastic electrolyte as a basic component,while the conductivity of most elastic electrolytes drops sharply during deformation,especially during large deformations.This is why highly stretchable LIBs have not yet been realized until now.As a proof of concept,a super-stretchable LIB with strain up to 1200%is created based on an intrinsically super-stretchable polymer electrolyte as the lithium-ion conductor.The super-stretchable conductive system is constructed by an effective diblock copolymerization strategy via photocuring of vinyl functionalized 2-ureido-4-pyrimidone(VFUpy),an acrylic monomer containing succinonitrile and a lithium salt,achieving high ionic conductivity(3.5×10^(-4)mS cm^(-1)at room temperature(RT))and large deformation(the strain can reach 4560%).The acrylic elastomer containing Li-ion conductive domains can strongly increase the compatibility between the neighboring elastic networks,resulting in high ionic conductivity under ultra-large deformation,while VFUpy increases elasticity modulus(over three times)and electrochemical stability(voltage window reaches 5.3 V)of the prepared polymer conductor.At a strain of up to 1200%,the resulting stretchable LIBs are still sufficient to power LEDs.This study sheds light on the design and development of high-performance intrinsically super-stretchable materials for the advancement of highly elastic energy storage devices for powering flexible/wearable electronics that can endure large deformation.
