The application of thermoelectric devices(TEDs)for personalized thermoregulation is attractive for saving energy while balancing the quality of life.TEDs that directly attach to human skin remarkably minimized the ene...The application of thermoelectric devices(TEDs)for personalized thermoregulation is attractive for saving energy while balancing the quality of life.TEDs that directly attach to human skin remarkably minimized the energy wasted for cooling the entire environment.However,facing the extreme dynamic geometry change and strain of human skin,conventional TEDs cannot align with the contour of our bodies for the best thermoregulation effect.Hence,we designed a kirigami-based wearable TED with excellent water vapor permeability,flexibility,and conformability.Numerical analysis and experimental results reveal that our product can withstand various types of large mechanical deformation without circuit rupture.The stated outcome and proposed facile approach not only reinforce the development of wearable TEDs but also offer an innovative opportunity for different electronics that require high conformability.展开更多
Kirigami arts have provided a more promising method for building multiscale structures,which can shape two-dimensional(2D)sheets into three-dimensional(3D)configurations by cutting and folding.Here,we first carried ou...Kirigami arts have provided a more promising method for building multiscale structures,which can shape two-dimensional(2D)sheets into three-dimensional(3D)configurations by cutting and folding.Here,we first carried out a theoretical analysis of the mechanical properties of 2D honeycomb lattice structures and experimental verification combined with finite element(FE)simulation.Furthermore,a series of thick-walled 3D kirigami-inspired honeycomb(TW3KH)structures with different mechanical properties were designed and fabricated on the exploration and optimization of geometric parameters of 2D honeycomb structures.The investigations of folding feasibility,self-expansion,and self-folding performance experimentally showed that our designed four-dimensional(4D)printing structure had good programmability and shape memory capability and a large volume change ratio during shape change.Meanwhile,research on its compression deformation behavior found that the TW3KH structures can recover load-bearing capacity very well when the angle is positive.Therefore,these TW3KH structures have great advantages in space-saving smart load-bearing equipment.展开更多
Wearable electronics are advancing towards miniaturization and flexibility.However,traditional energy supply methods have largely hindered their development.An effective solution to this problem is to convert human me...Wearable electronics are advancing towards miniaturization and flexibility.However,traditional energy supply methods have largely hindered their development.An effective solution to this problem is to convert human mechanical energy into electricity to power wearable electronic devices.Therefore,it is greatly attractive to design flexible,foldable and even stretchable energy harvesting devices.Herein,we use the electrospinning and kirigami approach to develop a type of highly stretchable kirigami-patterned nanofiber-based triboelectric nanogenerator(K-TENG).Due to its innovative structural design,the K-TENG can achieve a tensile strain of 220%,independent of the tensile properties of the material itself.When a person swings their arms,the K-TENG fixed to the clothing can convert mechanical energy from human movement into electrical energy.The produced electricity can directly drive 50 LED lights and a digital watch,or be stored in a lithium battery to charge the smartwatch and smartphone,respectively.This study employs a new method to fabricate a stretchable triboelectric nanogenerator and demonstrates its promising applications in wearable power technology.展开更多
Optical encryption,exploiting degrees of freedom of light as parameters to encode and decode information,plays an indispensable role in our daily life.Responsive structural color materials can give real-time visible f...Optical encryption,exploiting degrees of freedom of light as parameters to encode and decode information,plays an indispensable role in our daily life.Responsive structural color materials can give real-time visible feedback to external stimuli and provide ideal candidates for optical encryption.However,the development of existing responsive structural color materials is hindered by poor repeatability and long feedback time.Meanwhile,there are only few strategies to exploit structural colors in multichannel information encryption.Herein,bioinspired by the structural color variation due to a change in angle arising from the movement of animal’s scales or feathers,we developed a general multichannel information encryption strategy using a two-dimensional deformable kirigami arranging orientations of the grating arrays by design.The kirigami grating sheet shows rapid,repeatable,and programmable color change.This strategy utilizes the topological space deformation to guide the change of optical property,which suggests new possibilities for spatial and spectral encryption as well as mechano-sensing and camouflage.展开更多
In wearable electronics,significant research has gone into imparting stretchability and flexibility to otherwise rigid electronic components while maintaining their electrical properties.Thus far,this has been achieve...In wearable electronics,significant research has gone into imparting stretchability and flexibility to otherwise rigid electronic components while maintaining their electrical properties.Thus far,this has been achieved through various geometric modifications of the rigid conductive components themselves,such as with microcracked,buckled,or planar meander structures.Additionally,strategic placement of these resulting components within the overall devices,such as embedding them at the neutral plane,has been found to further enhance mechanical stability under deformation.However,these strategies are still limited in performance,failing to achieve fully strain-insensitive electrical performance under biaxial stretching,twisting,and mixed strain states.Here,we developed a new platform for wearable,motion artifact-free sensors using a graphene-based multiaxially stretchable kirigami-patterned mesh structure.The normalized resistance change of the electrodes and graphene embedded in the structure is smaller than 0.5%and 0.23%under 180°torsion and 100%biaxial strain,respectively.Moreover,the resistance change is limited to 5%under repeated stretching-releasing cycles from 0%to 100%biaxial strain.In addition,we investigated the deformation mechanisms of the structure with finite element analysis.Based on the simulation results,we derived a dimensionless geometric parameter that enables prediction of stretchability of the structure with high accuracy.Lastly,as a proof-of-concept,we demonstrated a biaxially-stretchable graphene-based sensor array capable of monitoring of temperature and glucose level with minimized motion-artifacts.展开更多
The recently emerging laser-induced graphene(LIG)technology,with one-step processing and designable features,has been widely used in the fabrication of wearable/portable electronics.Herein,by taking inspiration from k...The recently emerging laser-induced graphene(LIG)technology,with one-step processing and designable features,has been widely used in the fabrication of wearable/portable electronics.Herein,by taking inspiration from kirigami,we designed a stretchable supercapacitor(SC)step by step through controlling laser induction and cutting process on the polyimide(PI)film,with the use of one single CO_(2) laser source.Firstly,the carbonized basic geometric units of lines were produced on PI films to investigate the processing-structure relationships.Then,the complex photothermal conversion and heat transfer progress involved in the carbonized process were simulated by a photothermal model.Both experimental and theoretical results suggested that the laser power,scan rate and focus condition have great influence on the size,shape and morphology of the carbonized lines.Finally,we optimized the parameters of laser induction and cutting process to fabricate the kirigami-inspired SCs with reliable electrochemical properties and editable mechanical flexibility,showing great potential in the field of flexible electronics.展开更多
Kirigami is an art of paper cutting,which can be used in mechanical metamaterials,actuators,and energy absorption based on its deployable and load-deflection characteristics.Traditional cuts with zero width produce un...Kirigami is an art of paper cutting,which can be used in mechanical metamaterials,actuators,and energy absorption based on its deployable and load-deflection characteristics.Traditional cuts with zero width produce undesirable plastic deformation or even tear fracture due to stress concentration in stretching.This study proposes to enlarge the cut width into a notch flexure,which is applied to an orthogonality-cutted kirigami sheet,which buckles out of plane into a 3D configuration patterns under uniaxial tension.The use of compliant beam as the notch makes the stress distribution around the cuts more uniform in both elastic and elastoplastic regime.The experimental and numerical results show that by tuning the geometric parameters of cuts and material properties of the sheets,the trigger condition of 3D patterns can be adjusted.Potential capability of tunable phononic wave propagation in this kirigami-inspired metamaterial is demonstrated.This design methodology offers a theoretical guide for kirigami-based structures.展开更多
Magnetic kirigami with tunable configurations under magnetic actuation is of significant interest in various emerging fields.However,there remains a grand challenge to develop magnetic kirigami with a facile fabricati...Magnetic kirigami with tunable configurations under magnetic actuation is of significant interest in various emerging fields.However,there remains a grand challenge to develop magnetic kirigami with a facile fabrication strategy,programmable mag-netization,and functionality.In this work,we present a novel magnetic kirigami that is readily fabricated by the laser cutting technique.The magnetic kirigami consists of an array of magnetic microplates,each with a programmed magnetization.By applying an actuation magnetic field,each microplate can rotate and even flip,allowing for predesigned kirigami configura-tions.By further coating the surface of the microplate array,the magnetic kirigami can be programmed with functionality.We demonstrate a potential application of information encryption by engineering magnetic kirigami into a magneto-responsive QR code.Providing a simple fabrication strategy,our work paves the way for other applications of magnetic kirigami.展开更多
Kirigami, the ancient Japanese paper cutting technique, has been applied to achieve high stretchability and low energy loss of designed metallic glass. Despite the exploration of the underlying deformation mechanism o...Kirigami, the ancient Japanese paper cutting technique, has been applied to achieve high stretchability and low energy loss of designed metallic glass. Despite the exploration of the underlying deformation mechanism of kirigami-inspired structures from the energy point of view, the morphable responses of the kirigami patterns and the origin of the kirigami response are yet to be fully understood. This study reveals the mechanical driven-forms of the kirigami structure with the corresponding deformation stages. Based on the beam deflection theory, the elastic buckling behavior of kirigami metallic glass is manifested and a critical force prediction model is developed. Moreover, a force concentration parameter is introduced in the rigid-plastic deformation stage, predicting the nominal ultimate force. The kirigami-inspired facture force is firstly proposed. The findings of these models are in good agreement with the experimental sizedependent kirigami responses, and expected to provide significant insights into the understanding of the deformation behavior and the design of kirigami metallic glasses.展开更多
Given the rise in the popularity of wearable electronics that are able to deform into desirable configurations while maintaining electrochemical functionality,stretchable and flexible(hybrid)supercapacitors(SCs)have b...Given the rise in the popularity of wearable electronics that are able to deform into desirable configurations while maintaining electrochemical functionality,stretchable and flexible(hybrid)supercapacitors(SCs)have become increasingly of interest as innovative energy storage devices.Their outstanding power density,long lifetime with low capacitance loss,and appropriate energy density,in particular in hybrid cases make them ideal candidates for flexible electronics.The aim of this review paper is to provide an in-depth discussion of these stretchable and flexible SCs ranging from fabrication to electro-mechanical properties.This review paper begins with a short overview of the fundamentals of charge storage mechanisms and different types of multivalent metal-ion hybrid SCs.The research methods leading up to the current state of these stretchable and flexible SCs are then presented.This is followed by an in-depth presentation of the challenges associated with the fabrication methods for different configurations.Proposed novel strategies to maximize the elastic and electrochemical properties of stretchable/flexible or quasi-solid-state SCs are classified and the pros and cons associated with each are shown.The advances in mechanical properties and the expected advancements for the future of these SCs are discussed in the last section.展开更多
基金supported by the National Natural Science Foundation of China(No.62122002)the Project of City University of Hong Kong(Nos.9667221,9678274,and 9680322)+1 种基金as part of the InnoHK Project on Project 2.2—AI-based 3D ultrasound imaging algorithm at Hong Kong Centre for Cerebro-Cardiovascular Health Engineering(COCHE)the Project of Research Grants Council of the Hong Kong Special Administrative Region(Nos.11213721,11215722,and 11211523)。
文摘The application of thermoelectric devices(TEDs)for personalized thermoregulation is attractive for saving energy while balancing the quality of life.TEDs that directly attach to human skin remarkably minimized the energy wasted for cooling the entire environment.However,facing the extreme dynamic geometry change and strain of human skin,conventional TEDs cannot align with the contour of our bodies for the best thermoregulation effect.Hence,we designed a kirigami-based wearable TED with excellent water vapor permeability,flexibility,and conformability.Numerical analysis and experimental results reveal that our product can withstand various types of large mechanical deformation without circuit rupture.The stated outcome and proposed facile approach not only reinforce the development of wearable TEDs but also offer an innovative opportunity for different electronics that require high conformability.
基金This work was supported by the National Natural Science Foundation of China(Nos.12072094 and 12172106).
文摘Kirigami arts have provided a more promising method for building multiscale structures,which can shape two-dimensional(2D)sheets into three-dimensional(3D)configurations by cutting and folding.Here,we first carried out a theoretical analysis of the mechanical properties of 2D honeycomb lattice structures and experimental verification combined with finite element(FE)simulation.Furthermore,a series of thick-walled 3D kirigami-inspired honeycomb(TW3KH)structures with different mechanical properties were designed and fabricated on the exploration and optimization of geometric parameters of 2D honeycomb structures.The investigations of folding feasibility,self-expansion,and self-folding performance experimentally showed that our designed four-dimensional(4D)printing structure had good programmability and shape memory capability and a large volume change ratio during shape change.Meanwhile,research on its compression deformation behavior found that the TW3KH structures can recover load-bearing capacity very well when the angle is positive.Therefore,these TW3KH structures have great advantages in space-saving smart load-bearing equipment.
基金the China Postdoctoral Science Foundation(Grant No.2023TQ0316)the National Natural Science Foundation of China(Grant No.52273046).
文摘Wearable electronics are advancing towards miniaturization and flexibility.However,traditional energy supply methods have largely hindered their development.An effective solution to this problem is to convert human mechanical energy into electricity to power wearable electronic devices.Therefore,it is greatly attractive to design flexible,foldable and even stretchable energy harvesting devices.Herein,we use the electrospinning and kirigami approach to develop a type of highly stretchable kirigami-patterned nanofiber-based triboelectric nanogenerator(K-TENG).Due to its innovative structural design,the K-TENG can achieve a tensile strain of 220%,independent of the tensile properties of the material itself.When a person swings their arms,the K-TENG fixed to the clothing can convert mechanical energy from human movement into electrical energy.The produced electricity can directly drive 50 LED lights and a digital watch,or be stored in a lithium battery to charge the smartwatch and smartphone,respectively.This study employs a new method to fabricate a stretchable triboelectric nanogenerator and demonstrates its promising applications in wearable power technology.
基金supported by the National Key R&D Program of China(2022YFE0202000 and 2018YFA0208500)the National Science Fund for Distinguished Young Scholars(22225502)+3 种基金the National Natural Science Foundation of China(22073107,21522308,and 22150410331)Bureau of International Cooperation,Chinese Academy of Sciences(027GJHZ2022044MI)K.C.Wong Education Foundation,National Key R&D Program of China(2018YFA0208501)Youth Innovation Promotion Association,Chinese Academy of Sciences.
文摘Optical encryption,exploiting degrees of freedom of light as parameters to encode and decode information,plays an indispensable role in our daily life.Responsive structural color materials can give real-time visible feedback to external stimuli and provide ideal candidates for optical encryption.However,the development of existing responsive structural color materials is hindered by poor repeatability and long feedback time.Meanwhile,there are only few strategies to exploit structural colors in multichannel information encryption.Herein,bioinspired by the structural color variation due to a change in angle arising from the movement of animal’s scales or feathers,we developed a general multichannel information encryption strategy using a two-dimensional deformable kirigami arranging orientations of the grating arrays by design.The kirigami grating sheet shows rapid,repeatable,and programmable color change.This strategy utilizes the topological space deformation to guide the change of optical property,which suggests new possibilities for spatial and spectral encryption as well as mechano-sensing and camouflage.
基金S.N.gratefully acknowledges support from the AFOSR(Nos.FA2386-17-l-4071,FA9550-18-1-0405)KRICT(No.GOIKRICT KK1963-807)+2 种基金NSF(Nos.ECCS-1935775,CMMI-1554019,MRSEC DMR-1720633)NASA ECF(No.NNX16AR56G)ONR YIP(No.N00014-17-1-2830)and JITRI.Experiments were carried out in part in the Materials Research Laboratory Central Research Facilities,and Micro and Nano Technology Laboratory at the University of Illinois at Urbana-Champaign.
文摘In wearable electronics,significant research has gone into imparting stretchability and flexibility to otherwise rigid electronic components while maintaining their electrical properties.Thus far,this has been achieved through various geometric modifications of the rigid conductive components themselves,such as with microcracked,buckled,or planar meander structures.Additionally,strategic placement of these resulting components within the overall devices,such as embedding them at the neutral plane,has been found to further enhance mechanical stability under deformation.However,these strategies are still limited in performance,failing to achieve fully strain-insensitive electrical performance under biaxial stretching,twisting,and mixed strain states.Here,we developed a new platform for wearable,motion artifact-free sensors using a graphene-based multiaxially stretchable kirigami-patterned mesh structure.The normalized resistance change of the electrodes and graphene embedded in the structure is smaller than 0.5%and 0.23%under 180°torsion and 100%biaxial strain,respectively.Moreover,the resistance change is limited to 5%under repeated stretching-releasing cycles from 0%to 100%biaxial strain.In addition,we investigated the deformation mechanisms of the structure with finite element analysis.Based on the simulation results,we derived a dimensionless geometric parameter that enables prediction of stretchability of the structure with high accuracy.Lastly,as a proof-of-concept,we demonstrated a biaxially-stretchable graphene-based sensor array capable of monitoring of temperature and glucose level with minimized motion-artifacts.
基金the National Natural Science Foundation of China(Grant No.51775197)the Science and Technology Planning Project of Guangdong Province(Grant No.2018A050506007)the Guangzhou Science and Technology Program Project(Grant No.201704020090)。
文摘The recently emerging laser-induced graphene(LIG)technology,with one-step processing and designable features,has been widely used in the fabrication of wearable/portable electronics.Herein,by taking inspiration from kirigami,we designed a stretchable supercapacitor(SC)step by step through controlling laser induction and cutting process on the polyimide(PI)film,with the use of one single CO_(2) laser source.Firstly,the carbonized basic geometric units of lines were produced on PI films to investigate the processing-structure relationships.Then,the complex photothermal conversion and heat transfer progress involved in the carbonized process were simulated by a photothermal model.Both experimental and theoretical results suggested that the laser power,scan rate and focus condition have great influence on the size,shape and morphology of the carbonized lines.Finally,we optimized the parameters of laser induction and cutting process to fabricate the kirigami-inspired SCs with reliable electrochemical properties and editable mechanical flexibility,showing great potential in the field of flexible electronics.
基金This work was supported by the XJTU joint-collaboration project in multi-disciplines[xhj032021014-03]National Key Research and Development Program of China[2019YFB1311600]+1 种基金Shanxi Key Research and Development Program[2020ZDLGY06-11]Natural Science Foundation of China[No.52075411 and U1913213].
文摘Kirigami is an art of paper cutting,which can be used in mechanical metamaterials,actuators,and energy absorption based on its deployable and load-deflection characteristics.Traditional cuts with zero width produce undesirable plastic deformation or even tear fracture due to stress concentration in stretching.This study proposes to enlarge the cut width into a notch flexure,which is applied to an orthogonality-cutted kirigami sheet,which buckles out of plane into a 3D configuration patterns under uniaxial tension.The use of compliant beam as the notch makes the stress distribution around the cuts more uniform in both elastic and elastoplastic regime.The experimental and numerical results show that by tuning the geometric parameters of cuts and material properties of the sheets,the trigger condition of 3D patterns can be adjusted.Potential capability of tunable phononic wave propagation in this kirigami-inspired metamaterial is demonstrated.This design methodology offers a theoretical guide for kirigami-based structures.
基金National Natural Science Foundation of China(Project Nos.51975597,21872176,22072185,and 12272369)Natural Science Foundation of Guangdong Province(Project Nos.2019A1515011011 and 2022A1515011065)+3 种基金Special Support Plan for High Level Talents in Guangdong Province(Project No.2017TQ04X674)Key Research and Development Plan of Guangdong Province(Project No.2018B0909060)Pearl River Talents Program of Guangdong Province(Project No.2017GC010671)Organized scientific research project of Guangdong Normal University of Technology(Project No.22GPNUZDJS21).
文摘Magnetic kirigami with tunable configurations under magnetic actuation is of significant interest in various emerging fields.However,there remains a grand challenge to develop magnetic kirigami with a facile fabrication strategy,programmable mag-netization,and functionality.In this work,we present a novel magnetic kirigami that is readily fabricated by the laser cutting technique.The magnetic kirigami consists of an array of magnetic microplates,each with a programmed magnetization.By applying an actuation magnetic field,each microplate can rotate and even flip,allowing for predesigned kirigami configura-tions.By further coating the surface of the microplate array,the magnetic kirigami can be programmed with functionality.We demonstrate a potential application of information encryption by engineering magnetic kirigami into a magneto-responsive QR code.Providing a simple fabrication strategy,our work paves the way for other applications of magnetic kirigami.
基金fully supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region,China(Project No.PolyU 15222017)。
文摘Kirigami, the ancient Japanese paper cutting technique, has been applied to achieve high stretchability and low energy loss of designed metallic glass. Despite the exploration of the underlying deformation mechanism of kirigami-inspired structures from the energy point of view, the morphable responses of the kirigami patterns and the origin of the kirigami response are yet to be fully understood. This study reveals the mechanical driven-forms of the kirigami structure with the corresponding deformation stages. Based on the beam deflection theory, the elastic buckling behavior of kirigami metallic glass is manifested and a critical force prediction model is developed. Moreover, a force concentration parameter is introduced in the rigid-plastic deformation stage, predicting the nominal ultimate force. The kirigami-inspired facture force is firstly proposed. The findings of these models are in good agreement with the experimental sizedependent kirigami responses, and expected to provide significant insights into the understanding of the deformation behavior and the design of kirigami metallic glasses.
文摘Given the rise in the popularity of wearable electronics that are able to deform into desirable configurations while maintaining electrochemical functionality,stretchable and flexible(hybrid)supercapacitors(SCs)have become increasingly of interest as innovative energy storage devices.Their outstanding power density,long lifetime with low capacitance loss,and appropriate energy density,in particular in hybrid cases make them ideal candidates for flexible electronics.The aim of this review paper is to provide an in-depth discussion of these stretchable and flexible SCs ranging from fabrication to electro-mechanical properties.This review paper begins with a short overview of the fundamentals of charge storage mechanisms and different types of multivalent metal-ion hybrid SCs.The research methods leading up to the current state of these stretchable and flexible SCs are then presented.This is followed by an in-depth presentation of the challenges associated with the fabrication methods for different configurations.Proposed novel strategies to maximize the elastic and electrochemical properties of stretchable/flexible or quasi-solid-state SCs are classified and the pros and cons associated with each are shown.The advances in mechanical properties and the expected advancements for the future of these SCs are discussed in the last section.
