The mass production of primed electronics can be achieved by roll-to-roll（R2R） printing system, so highly accurate web tension is required that can minimize the register error and keep the thickness and roughness of...The mass production of primed electronics can be achieved by roll-to-roll（R2R） printing system, so highly accurate web tension is required that can minimize the register error and keep the thickness and roughness of printed devices in limits. The web tension of a R2R system is regulated by the use of integrated load cells and active dancer system for printed electronics applications using decentralized multi-input-single-output（MISO） regularized variable learning rate backpropagation artificial neural networks. The active dancer system is used before printing system to reduce disturbances in the web tension of process span. The classical PID control result in tension spikes with the change in roll diameter of winder and unwinder rolls. The presence of dancer in R2R system shows that improved web tension control in printing span and the web tension can be enhanced from 3.75 N to 4.75 N. The overshoot of system is less than ±2.5 N and steady state error is within ± 1 N where load cells have a signal noise of ±0.7 N. The integration of load cells and active dancer with self-adapting neural network control provide a solution to the web tension control of multispan roll-to-roll system.展开更多
The healthcare system is moving away from traditional hospital-centric models towards a more personalised,patient-centric approach driven by the concept called‘lab on wearables’.The nucleus of this concept is ground...The healthcare system is moving away from traditional hospital-centric models towards a more personalised,patient-centric approach driven by the concept called‘lab on wearables’.The nucleus of this concept is grounded on the translation of biological signals into actionable healing information with the help of soft,conformable and biocompatible sensors.This soft flexible electronic platform development is more leaning towards unconventional electronics fabrication routes like printed electronics over clean room based micro-electronics manufacturing.Printed electronics can harness the potential of stretchable foils,bio-derived functional materials and organic electronics,enabling the development of biodegradable and bioresorbable wound monitoring systems that are conformable with the skin.The review explores the potential of sustainable and biocompatible printed electronics in transducing wound biomarkers into actionable healing insights,enabling timely interventions.This work also provides a roadmap for printed electronics-based wound monitoring and on-demand treatment solutions,offering a glimpse into the future promises of the technology.展开更多
The field of printed electronics has been extensively researched for its versatility and scalability in flexible and large-area applications.Impedance is of great importance for the performance and reliability of elec...The field of printed electronics has been extensively researched for its versatility and scalability in flexible and large-area applications.Impedance is of great importance for the performance and reliability of electronics.However,its measurement requires electrical contacts,which makes it difficult on complex or bio-interfaces.Although the printing process is accessible,impedance characterization may be cumbersome,which can create a bottleneck during the manufacturing process.This paper reports the first effort at developing a convolutional neural network(CNN)based image regression model to replace impedance spectroscopy(IS).In our study,the CNN model learned the features of inkjet-printed electrode images that are dependent on the printing and sintering of nanomaterials and quantitatively predicted the resistance and capacitance of the equivalent circuit of the inkjet-printed lines.The image-based impedance spectroscopy(IIS)is expected to be the cornerstone as a revolutionary approach to electronics research and development enabled by deep neural networks.展开更多
This study investigates laser sintering of Cu particle-free ink(Cu formate tetrahydrate—amino-2-propanol complex)as an alternative to conventional sintering in an oven(under inert/reducing atmosphere).Utilizing benef...This study investigates laser sintering of Cu particle-free ink(Cu formate tetrahydrate—amino-2-propanol complex)as an alternative to conventional sintering in an oven(under inert/reducing atmosphere).Utilizing benefits of high-speed localized heating using laser,substrate damage can be prevented for low-melting substrates such as Polyethylene Terephthalate(PET).Firstly,a suitable sintering process window is achieved based on energy density for two different flexible polymeric susbtrates:Polyimide and PET using different laser parameters(laser power,scan rate and spot diameter).Subsequently,characterization of laser sintered traces are also made using different laser optic profiles(Gaussian and top hat).Different methodologies for fabrication of metallized Cu layer were also demonstrated.A very low bulk resistivity of 3.24µΩcm(1.87 times of bulk Cu)was achieved on trace thickness of 0.85±0.15µm exhibiting good adherence to polymeric substrates.A promising fabrication process of low-cost and reliable flexible printed electronic devices is demonstrated.展开更多
Stable aqueous carbon inks,with graphene sheets(GSs)and carbon black(CB)as conductive fillers,are prepared by a simple one-pot ball-milling method.The asprepared composite ink with 10 wt%GSs shows optimized rheologica...Stable aqueous carbon inks,with graphene sheets(GSs)and carbon black(CB)as conductive fillers,are prepared by a simple one-pot ball-milling method.The asprepared composite ink with 10 wt%GSs shows optimized rheological properties(viscosity and thixotropy)for screen printing.The as-printed coatings based on the above ink are uniform and dense on a polyimide substrate,and exhibit a sandwich-type conductive three dimensional network at the microscale.The resistivity of the typical composite coating is as low as 0.23±0.01Ωcm(92±4Ωsq^-1,25μm),which is 30%as that of a pure CB coating(0.77±0.01Ωcm).It is noteworthy that the resistivity decreases to 0.18±0.01Ωcm(72±4Ωsq^-1,25μm)after a further rolling compression.The coating exhibits good mechanical flexibility,and the resistance slightly increases by 12%after 3000 bending cycles.With the CB/GSs composite coatings as a flexible conductor,fascinating luminescent bookmarks and membrane switches were fabricated,demonstrating the tremendous potential of these coatings in the commercial production of flexible electronics and devices.展开更多
Liquid metal based printed electronics was a newly emerging frontier in recent years. However, restricted by the single silver-white appearance of the liquid metal （LM）, the colors of currently available printed ele...Liquid metal based printed electronics was a newly emerging frontier in recent years. However, restricted by the single silver-white appearance of the liquid metal （LM）, the colors of currently available printed electronics were rather limited. Here, a new conceptual LM based colorful printed electronics was proposed where electrical wires and circuits with numerous colors can be made via a straightforward, efficient and accurate printing procedure. Firstly, the LM was printed on the substrate to construct a conductive wire. Then it was frozen to a solid. Subsequently, colorful pigments were coated on the originally printed liquid metal conductive wires, which finally were packaged with PDMS. Such multicolored conductive wire exhibits excellent conductivity, and good temperature resistance （do not fade at high temperature）. Further, the adhesion mechanism of the mineral pigments on the liquid metal layer was disclosed. And the pigment layer was discovered to well protect the LM from the outside environments, and enhance the durability of the LM conductive wire at the same time. These multicolored liquid metal wires take an aesthetic appearance, excellent printability, flexibility, large conductivity and stable performance, which would significantly enhance the sense of beanty and experience when compared to the conventional printed electronics.展开更多
This study explores the feasibility of different laser systems to sinter screen-printed lines from nonconductive copper nanoparticles(Cu NPs)on polyethylene terephthalate polymer film.These materials are commonly used...This study explores the feasibility of different laser systems to sinter screen-printed lines from nonconductive copper nanoparticles(Cu NPs)on polyethylene terephthalate polymer film.These materials are commonly used in manufacturing functional printed electronics for large-area applications.Here,optical and thermal characterization of the materials is conducted to identify suitable laser sources and process conditions.Direct diode(808 nm),Nd:YAG(1064 nm and second harmonic of 532 nm),and ytterbium fiber(1070 nm)lasers are explored.Optimal parameters for sintering the Cu NPs are identified for each laser system,which targets low resistivity and high processing speed.Finally,the quality of the sintered tracks is quantified,and the laser sintering mechanisms observed under different wavelengths are analyzed.Practical considerations are discussed to improve the laser sintering process of Cu NPs.展开更多
A new generation of RFID materials with de- signed-in compatibility helps raise quality, reliability and process efficiency If RFID technology is headed for the heights predicted by forecasters, it will require an ong...A new generation of RFID materials with de- signed-in compatibility helps raise quality, reliability and process efficiency If RFID technology is headed for the heights predicted by forecasters, it will require an ongoing evolution of new materials and re- lated technologies to help reduce card/label assembly costs and improve performance. From a materials standpoint, the critical elements in any printed RFID inlay include the chip, the chip attachment method, the antenna,展开更多
Disposable devices designed for single and/or multiple reliable measurements over a short duration have attracted considerable interest recently. However, these devices often use non-recyclable and non-biodegradable m...Disposable devices designed for single and/or multiple reliable measurements over a short duration have attracted considerable interest recently. However, these devices often use non-recyclable and non-biodegradable materials and wasteful fabrication methods. Herein, we present ZnO nanowires(NWs) based degradable high-performance UV photodetectors(PDs) on flexible chitosan substrate. Systematic investigations reveal the presented device exhibits excellent photo response, including high responsivity(55 A/W), superior specific detectivity(4×10^(14) jones), and the highest gain(8.5×10~(10)) among the reported state of the art biodegradable PDs. Further, the presented PDs display excellent mechanical flexibility under wide range of bending conditions and thermal stability in the measured temperature range(5–50 ℃).The biodegradability studies performed on the device, in both deionized(DI) water(pH≈6) and PBS solution(pH=7.4),show fast degradability in DI water(20 mins) as compared to PBS(48 h). These results show the potential the presented approach holds for green and cost-effective fabrication of wearable, and disposable sensing systems with reduced adverse environmental impact.展开更多
Metal oxide thin-films transistors(TFTs)produced from solution-based printing techniques can lead to large-area electronics with low cost.However,the performance of current printed devices is inferior to those from va...Metal oxide thin-films transistors(TFTs)produced from solution-based printing techniques can lead to large-area electronics with low cost.However,the performance of current printed devices is inferior to those from vacuum-based methods due to poor film uniformity induced by the“coffeering”effect.Here,we report a novel approach to print highperformance indium tin oxide(ITO)-based TFTs and logic inverters by taking advantage of such notorious effect.ITO has high electrical conductivity and is generally used as an electrode material.However,by reducing the film thickness down to nanometers scale,the carrier concentration of ITO can be effectively reduced to enable new applications as active channels in transistors.The ultrathin(~10-nm-thick)ITO film in the center of the coffee-ring worked as semiconducting channels,while the thick ITO ridges(>18-nm-thick)served as the contact electrodes.The fully inkjet-printed ITO TFTs exhibited a high saturation mobility of 34.9 cm2 V^(−1) s^(−1) and a low subthreshold swing of 105 mV dec^(−1).In addition,the devices exhibited excellent electrical stability under positive bias illumination stress(PBIS,ΔV_(th)=0.31 V)and negative bias illuminaiton stress(NBIS,ΔV_(th)=−0.29 V)after 10,000 s voltage bias tests.More remarkably,fully printed n-type metal–oxide–semiconductor(NMOS)inverter based on ITO TFTs exhibited an extremely high gain of 181 at a low-supply voltage of 3 V,promising for advanced electronics applications.展开更多
It has long been a dream in the electronics industry to be able to write out electronics directly, as simply as printing a picture onto paper with an offi ce printer. The fi rstever prototype of a liquid-metal printer...It has long been a dream in the electronics industry to be able to write out electronics directly, as simply as printing a picture onto paper with an offi ce printer. The fi rstever prototype of a liquid-metal printer has been invented and demonstrated by our lab, bringing this goal a key step closer. As part of a continuous endeavor, this work is dedicated to significantly extending such technology to the consumer level by making a very practical desktop liquid-metal printer for society in the near future. Through the industrial design and technical optimization of a series of key technical issues such as working reliability, printing resolution, automatic control, human-machine interface design, software, hardware, and integration between software and hardware, a high-quality personal desktop liquid-metal printer that is ready for mass production in industry was fabricated. Its basic features and important technical mechanisms are explained in this paper, along with demonstrations of several possible consumer end-uses for making functional devices such as li ght-emitting diode(LED) displays. This liquid-metal printer is an automatic, easyto-use, and low-cost personal electronics manufacturing tool with many possible applications. This paper discusses important roles that the new machine may play for a group of emerging needs. The prospective future of this cuttingedge technology is outlined, along with a comparative interpretation of several historical printing methods. This desktop liquid-metal printer is expected to become a basic electronics manufacturing tool for a wide variety of emerging practices in the academic realm, in industry, and in education as well as for individual end-users in the near future.展开更多
In order to overcome the shortcomings of low-cost anti-oxidation conductive ink and its preparation method in the field of printing electronics, core-shell coated Cu@Ag nanoparticles were used to prepare conductive in...In order to overcome the shortcomings of low-cost anti-oxidation conductive ink and its preparation method in the field of printing electronics, core-shell coated Cu@Ag nanoparticles were used to prepare conductive ink, and a printed circuit was obtained by inkjet printing. Copper nanoparticles were prepared by a chemical reduction method and then coated with Cu@Ag particles by a copper-based self-catalytic reaction. Conductive ink was prepared by ball milling and dispersion and printed on PI film to form a conductive coating. After characterization and analysis, the particle size and dispersion of the obtained Cu@Ag meet the requirements and can be stored stably under normal atmospheric conditions. The resistivity of the conductive film sintered at 300˚C is only 10.6 μΩ<span style="font-size:10.0pt;font-family:"">∙</span>cm.展开更多
Achieving simultaneous high conductivity and mechanical durability in printed flexible electronics remains a central challenge.Here we report a systematic investigation of silver nanoparticle(AgNP)size effects on film...Achieving simultaneous high conductivity and mechanical durability in printed flexible electronics remains a central challenge.Here we report a systematic investigation of silver nanoparticle(AgNP)size effects on film performance using a pH-mediated synthesis that decouples particle size from organic content.This strategy enables direct assessment of size-dependent sintering and mechanical behaviors,previously obscured by varied polymer concentrations of traditional size control methods.With consistent organic content,AgNPs of smaller size demonstrated more effective sintering,forming denser and more cohesive microstructures,contrary to prior reports with varied organic concentration.This yielded highly conductive films with resistivities as low as 2.34μΩcm,approaching bulk silver.Additionally,electrohydrodynamic(EHD)printing of these inks produced flexible circuits with significantly improved mechanical resilience.The resistance of a printed pattern remained stable over 1,000 bending cycles at a 2.9 mm radius and increased by only 56.7%after 50,000 cycles,with no visible microstructural cracking.展开更多
It has been more than three decades since stereolithography began to emerge in various forms of additive manufacturing and 3D printing. Today these technologies are proliferating worldwide in various forms of advanced...It has been more than three decades since stereolithography began to emerge in various forms of additive manufacturing and 3D printing. Today these technologies are proliferating worldwide in various forms of advanced manufacturing. The largest segment of the 3D printing market today involves various polymer component fabrications, particularly complex structures not attainable by other manufacturing methods.Conventional printer head systems have also been adapted to selectively print various speciated human cells and special molecules in attempts to construct human organs, beginning with skin and various tissue patches. These efforts are discussed along with metal and alloy fabrication of a variety of implant and bone replacement components by creating powder layers, which are selectively melted into complex forms（such as foams and other open-cellular structures） using laser and electron beams directed by CAD software. Efforts to create a ＂living implant＂ by bone ingrowth and eventual vascularization within these implants will be discussed briefly. Novel printer heads for direct metal droplet deposition as in other 3D printing systems are briefly described since these concepts will allow for the eventual fabrication of very large and complex products, including automotive and aerospace structures and components.展开更多
In a rational exercise, in the present paper it is extrapolated how the development of ICTs （information and communication technologies） and the incipient technological development of additive manufacturing has the ...In a rational exercise, in the present paper it is extrapolated how the development of ICTs （information and communication technologies） and the incipient technological development of additive manufacturing has the potential to change our society. In the following, it is analyzing the evolution of man over physical matter and how this has shaped our society. The main milestones or key stages in history that have marked a transcendental change in the human-machine-environment relationship have been identified and consequently have led us to ask ourselves： What is next, how far are we, and what are we capable of printing？ In an attempt to identify the current state of the art, highlighting the possibilities those additive technologies can offer.展开更多
In this paper, a flexible and stretchable circuit has been fabricated by the printing method based on Ag NWs/PDMS composite. The randomly oriented Ag NWs were buried in PDMS to form a conductive and stretchable electr...In this paper, a flexible and stretchable circuit has been fabricated by the printing method based on Ag NWs/PDMS composite. The randomly oriented Ag NWs were buried in PDMS to form a conductive and stretchable electrode. Stable conductivity was achieved with a large range of tensile strain（0-50%） after the initial stretching/releasing cycle. The stable electrical response is due to the buckling of the Ag NWs/PDMS composite layer. Furthermore, printed stretchable circuits integrated with commercial ICs have been demonstrated for wearable applications.展开更多
We combined lightweight and mechanically flexible printed transistors and actuators with a paper unmanned aerial vehicle(UAV)glider prototype to demonstrate electrically controlled glide path modification in a lightwe...We combined lightweight and mechanically flexible printed transistors and actuators with a paper unmanned aerial vehicle(UAV)glider prototype to demonstrate electrically controlled glide path modification in a lightweight,disposable UAV system.The integration of lightweight and mechanically flexible electronics that is offered by printed electronics is uniquely attractive in this regard because it enables flight control in an inexpensive,disposable,and easily integrated system.Here,we demonstrate electroactive polymer(EAP)actuators that are directly printed into paper that act as steering elements for low cost,lightweight paper UAVs.We drive these actuators by using ion gel-gated organic thin film transistors(OTFTs)that are ideally suited as drive transistors for these actuators in terms of drive current and frequency requirements.By using a printing-based fabrication process on a paper glider,we are able to deliver an attractive path to the realization of inexpensive UAVs for ubiquitous sensing and monitoring flight applications.展开更多
Nitrate is the primary water-soluble macronutrient essential for plant growth that is converted from excess fish feeds,fish effluents,and degrading biomaterials on the aquaponic pond floor,and when aquacultural malpra...Nitrate is the primary water-soluble macronutrient essential for plant growth that is converted from excess fish feeds,fish effluents,and degrading biomaterials on the aquaponic pond floor,and when aquacultural malpractices occur,large amounts of it retain in the water system causing increase rate in eutrophication and toxifies fish and aquaculture plants.Recent nitrate sensor prototypes still require performing the additional steps of water sample deionization and dilution and were constructed with expensive materials.In response to the challenge of sensor enhancement and aquaponic water quality monitoring,this study developed sensitive,repeatable,and reproducible screen-printed graphite electrodes on polyvinyl chloride and parchment paper substrates with silver as electrode material and 60:40 graphite powder:nail polish formulated conductive ink for electrical traces,integrated with 9-gene genetic expression model as a function of peak anodic current and electrochemical test time for nitrate concentration prediction that is embedded into low-power Arduino ESP32 for in situ nitrate sensing in aquaponic pond water.Five SPE electrical traces were designed on the two types of substrates.Scanning electron microscopy with energy dispersive X-ray confirmed the electrode surface morphology.Electrochemical cyclic voltammetry using 10 to 100 mg/L KNO3 and water from three-depth regions of the actual pond established the electrochemical test time(10.5 s)and electrode potential(0.135 V)protocol necessary to produce peak current that corresponds to the strength of nitrate ions during redox.The findings from in situ testing revealed that the proposed sensors have strong linear predictions(R2=0.968 MSE=1.659 for nSPEv and R2=0.966 MSE=4.697 for nSPEp)in the range of 10 to 100 mg/L and best detection limit of 3.15μg/L,which are comparable to other sensors of more complex construction.The developed three-electrode electrochemical nitrate sensor confirms that it is reliable for both biosensing in controlled solutions and in situ aquaponic pond water systems.展开更多
In this work, a simple methodology was developed to enhance the patterning resolution of inkjet printing, involving process optimization as well as substrate modification and treatment. The line width of the inkjetpri...In this work, a simple methodology was developed to enhance the patterning resolution of inkjet printing, involving process optimization as well as substrate modification and treatment. The line width of the inkjetprinted silver lines was successfully reduced to 1/3 of the original value using this methodology. Large-area flexible circuits with delicate patterns and good morphology were thus fabricated. The resultant flexible circuits showed excellent electrical conductivity as low as 4.5 Ω/□ and strong tolerance to mechanical bending. The simple methodology is also applicable to substrates with various wettability, which suggests a general strategy to enhance the printing quality of inkjet printing for manufacturing high-performance large-area flexible electronics.展开更多
Continuously printable electronics have the significant advantage of being efficient for fabricating conductive polymer composites;however,the precise tailoring of the 3D hierarchical morphology of conductive nanocomp...Continuously printable electronics have the significant advantage of being efficient for fabricating conductive polymer composites;however,the precise tailoring of the 3D hierarchical morphology of conductive nanocomposites in a simple dripping step remains challenging.Here,we introduce a one-step direct printing technique to construct diverse microdome morphologies influenced by the interfacial Marangoni effect and nanoparticle interactions.Using a jet dispenser for continuous processing,we effectively fabricated a soft epidermislike e-skin containing 64 densely arrayed pressure sensing pixels with a hierarchical dome array for enhanced linearity and ultrasensitivity.The e-skin has 36 temperature-sensing pixels in the outer layer,with a shield-shaped dome that is insensitive to pressure stimuli.Our prosthetic finger inserted with the printed sensor arrays was capable of ultragentle detection and manipulation,such as stably holding a fragile biscuit,using a soft dropper to elaborately produce water droplets and harvesting soft fruits;these activities are challenging for existing high-sensitivity tactile sensors.展开更多
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF),Ministry of Education,Science and Technology,Korea(Grant No.2010-0026163)Strategy Technology Development Project,Ministry of Knowledge Economy,Korea(Grant No.10032149)
文摘The mass production of primed electronics can be achieved by roll-to-roll（R2R） printing system, so highly accurate web tension is required that can minimize the register error and keep the thickness and roughness of printed devices in limits. The web tension of a R2R system is regulated by the use of integrated load cells and active dancer system for printed electronics applications using decentralized multi-input-single-output（MISO） regularized variable learning rate backpropagation artificial neural networks. The active dancer system is used before printing system to reduce disturbances in the web tension of process span. The classical PID control result in tension spikes with the change in roll diameter of winder and unwinder rolls. The presence of dancer in R2R system shows that improved web tension control in printing span and the web tension can be enhanced from 3.75 N to 4.75 N. The overshoot of system is less than ±2.5 N and steady state error is within ± 1 N where load cells have a signal noise of ±0.7 N. The integration of load cells and active dancer with self-adapting neural network control provide a solution to the web tension control of multispan roll-to-roll system.
文摘The healthcare system is moving away from traditional hospital-centric models towards a more personalised,patient-centric approach driven by the concept called‘lab on wearables’.The nucleus of this concept is grounded on the translation of biological signals into actionable healing information with the help of soft,conformable and biocompatible sensors.This soft flexible electronic platform development is more leaning towards unconventional electronics fabrication routes like printed electronics over clean room based micro-electronics manufacturing.Printed electronics can harness the potential of stretchable foils,bio-derived functional materials and organic electronics,enabling the development of biodegradable and bioresorbable wound monitoring systems that are conformable with the skin.The review explores the potential of sustainable and biocompatible printed electronics in transducing wound biomarkers into actionable healing insights,enabling timely interventions.This work also provides a roadmap for printed electronics-based wound monitoring and on-demand treatment solutions,offering a glimpse into the future promises of the technology.
基金supported by the Ministry of Education through the Basic Science Research Program through the National Research Foundation of Korea(NRF-2021R1I1A3059714)by the Korea Institute of Industrial Technology as"Development of root technology for multi-product flexible production(KITECH EO-24-0009)+1 种基金supported by project for Collabo R&Dbetween Industry,University,and Research Institute funded by Korea Ministry of SMEs and Startups in 2023(RS-2023-00224114)supported by the faculty research fund of Sejong University in 2024。
文摘The field of printed electronics has been extensively researched for its versatility and scalability in flexible and large-area applications.Impedance is of great importance for the performance and reliability of electronics.However,its measurement requires electrical contacts,which makes it difficult on complex or bio-interfaces.Although the printing process is accessible,impedance characterization may be cumbersome,which can create a bottleneck during the manufacturing process.This paper reports the first effort at developing a convolutional neural network(CNN)based image regression model to replace impedance spectroscopy(IS).In our study,the CNN model learned the features of inkjet-printed electrode images that are dependent on the printing and sintering of nanomaterials and quantitatively predicted the resistance and capacitance of the equivalent circuit of the inkjet-printed lines.The image-based impedance spectroscopy(IIS)is expected to be the cornerstone as a revolutionary approach to electronics research and development enabled by deep neural networks.
基金supported by the Bavarian Collaborative Research Program(BayVFP)of the Free State of Bavaria,Germany within the project‘ADDIRA’’under the grant number DIE-2107-005//DIE0159/01Laser facility at Liverpool John Moore University,Faculty of Engineering and Technology funded through FET Pump Prime Awards 2023/2024.
文摘This study investigates laser sintering of Cu particle-free ink(Cu formate tetrahydrate—amino-2-propanol complex)as an alternative to conventional sintering in an oven(under inert/reducing atmosphere).Utilizing benefits of high-speed localized heating using laser,substrate damage can be prevented for low-melting substrates such as Polyethylene Terephthalate(PET).Firstly,a suitable sintering process window is achieved based on energy density for two different flexible polymeric susbtrates:Polyimide and PET using different laser parameters(laser power,scan rate and spot diameter).Subsequently,characterization of laser sintered traces are also made using different laser optic profiles(Gaussian and top hat).Different methodologies for fabrication of metallized Cu layer were also demonstrated.A very low bulk resistivity of 3.24µΩcm(1.87 times of bulk Cu)was achieved on trace thickness of 0.85±0.15µm exhibiting good adherence to polymeric substrates.A promising fabrication process of low-cost and reliable flexible printed electronic devices is demonstrated.
基金supported by the Scientific and Technological Key Project of Shanxi Province (MC2016-04 and MC2016-08)Natural Science Foundation of Shanxi Province (201801D221156)+2 种基金DNL Cooperation Fund of CAS (DNL180308)Science and Technology Service Network Initiative of CAS (KFJ-STS-ZDTP-068)Youth Innovation Promotion Association of CAS
文摘Stable aqueous carbon inks,with graphene sheets(GSs)and carbon black(CB)as conductive fillers,are prepared by a simple one-pot ball-milling method.The asprepared composite ink with 10 wt%GSs shows optimized rheological properties(viscosity and thixotropy)for screen printing.The as-printed coatings based on the above ink are uniform and dense on a polyimide substrate,and exhibit a sandwich-type conductive three dimensional network at the microscale.The resistivity of the typical composite coating is as low as 0.23±0.01Ωcm(92±4Ωsq^-1,25μm),which is 30%as that of a pure CB coating(0.77±0.01Ωcm).It is noteworthy that the resistivity decreases to 0.18±0.01Ωcm(72±4Ωsq^-1,25μm)after a further rolling compression.The coating exhibits good mechanical flexibility,and the resistance slightly increases by 12%after 3000 bending cycles.With the CB/GSs composite coatings as a flexible conductor,fascinating luminescent bookmarks and membrane switches were fabricated,demonstrating the tremendous potential of these coatings in the commercial production of flexible electronics and devices.
基金supported by Beijing Municipal Science and Technology Funding(Grant No.Z151100003715002)Key Project Funding of Chinese Academy of Sciences
文摘Liquid metal based printed electronics was a newly emerging frontier in recent years. However, restricted by the single silver-white appearance of the liquid metal （LM）, the colors of currently available printed electronics were rather limited. Here, a new conceptual LM based colorful printed electronics was proposed where electrical wires and circuits with numerous colors can be made via a straightforward, efficient and accurate printing procedure. Firstly, the LM was printed on the substrate to construct a conductive wire. Then it was frozen to a solid. Subsequently, colorful pigments were coated on the originally printed liquid metal conductive wires, which finally were packaged with PDMS. Such multicolored conductive wire exhibits excellent conductivity, and good temperature resistance （do not fade at high temperature）. Further, the adhesion mechanism of the mineral pigments on the liquid metal layer was disclosed. And the pigment layer was discovered to well protect the LM from the outside environments, and enhance the durability of the LM conductive wire at the same time. These multicolored liquid metal wires take an aesthetic appearance, excellent printability, flexibility, large conductivity and stable performance, which would significantly enhance the sense of beanty and experience when compared to the conventional printed electronics.
基金The corresponding author,Hongyu Zheng,would like to acknowledge the grant support of Shandong Taishan Scholar Scheme(Grant No.ts20190401).
文摘This study explores the feasibility of different laser systems to sinter screen-printed lines from nonconductive copper nanoparticles(Cu NPs)on polyethylene terephthalate polymer film.These materials are commonly used in manufacturing functional printed electronics for large-area applications.Here,optical and thermal characterization of the materials is conducted to identify suitable laser sources and process conditions.Direct diode(808 nm),Nd:YAG(1064 nm and second harmonic of 532 nm),and ytterbium fiber(1070 nm)lasers are explored.Optimal parameters for sintering the Cu NPs are identified for each laser system,which targets low resistivity and high processing speed.Finally,the quality of the sintered tracks is quantified,and the laser sintering mechanisms observed under different wavelengths are analyzed.Practical considerations are discussed to improve the laser sintering process of Cu NPs.
文摘A new generation of RFID materials with de- signed-in compatibility helps raise quality, reliability and process efficiency If RFID technology is headed for the heights predicted by forecasters, it will require an ongoing evolution of new materials and re- lated technologies to help reduce card/label assembly costs and improve performance. From a materials standpoint, the critical elements in any printed RFID inlay include the chip, the chip attachment method, the antenna,
基金supported in part by Engineering and Physical Science Research Council (EPSRC) through Engineering Fellowship (EP/R029644/1)Hetero-print Programme Grant (EP/R03480X/1)European Commission through grant references (H2020-MSCAITN2019-861166)。
文摘Disposable devices designed for single and/or multiple reliable measurements over a short duration have attracted considerable interest recently. However, these devices often use non-recyclable and non-biodegradable materials and wasteful fabrication methods. Herein, we present ZnO nanowires(NWs) based degradable high-performance UV photodetectors(PDs) on flexible chitosan substrate. Systematic investigations reveal the presented device exhibits excellent photo response, including high responsivity(55 A/W), superior specific detectivity(4×10^(14) jones), and the highest gain(8.5×10~(10)) among the reported state of the art biodegradable PDs. Further, the presented PDs display excellent mechanical flexibility under wide range of bending conditions and thermal stability in the measured temperature range(5–50 ℃).The biodegradability studies performed on the device, in both deionized(DI) water(pH≈6) and PBS solution(pH=7.4),show fast degradability in DI water(20 mins) as compared to PBS(48 h). These results show the potential the presented approach holds for green and cost-effective fabrication of wearable, and disposable sensing systems with reduced adverse environmental impact.
基金This research was financially supported under the Westlake Multidisciplinary Research Initiative Center(MRIC)Seed Fund(Grant No.MRIC20200101).
文摘Metal oxide thin-films transistors(TFTs)produced from solution-based printing techniques can lead to large-area electronics with low cost.However,the performance of current printed devices is inferior to those from vacuum-based methods due to poor film uniformity induced by the“coffeering”effect.Here,we report a novel approach to print highperformance indium tin oxide(ITO)-based TFTs and logic inverters by taking advantage of such notorious effect.ITO has high electrical conductivity and is generally used as an electrode material.However,by reducing the film thickness down to nanometers scale,the carrier concentration of ITO can be effectively reduced to enable new applications as active channels in transistors.The ultrathin(~10-nm-thick)ITO film in the center of the coffee-ring worked as semiconducting channels,while the thick ITO ridges(>18-nm-thick)served as the contact electrodes.The fully inkjet-printed ITO TFTs exhibited a high saturation mobility of 34.9 cm2 V^(−1) s^(−1) and a low subthreshold swing of 105 mV dec^(−1).In addition,the devices exhibited excellent electrical stability under positive bias illumination stress(PBIS,ΔV_(th)=0.31 V)and negative bias illuminaiton stress(NBIS,ΔV_(th)=−0.29 V)after 10,000 s voltage bias tests.More remarkably,fully printed n-type metal–oxide–semiconductor(NMOS)inverter based on ITO TFTs exhibited an extremely high gain of 181 at a low-supply voltage of 3 V,promising for advanced electronics applications.
基金supported by the Research Funding of the Chinese Academy of Sciences (KGZD-EW-T04-4)
文摘It has long been a dream in the electronics industry to be able to write out electronics directly, as simply as printing a picture onto paper with an offi ce printer. The fi rstever prototype of a liquid-metal printer has been invented and demonstrated by our lab, bringing this goal a key step closer. As part of a continuous endeavor, this work is dedicated to significantly extending such technology to the consumer level by making a very practical desktop liquid-metal printer for society in the near future. Through the industrial design and technical optimization of a series of key technical issues such as working reliability, printing resolution, automatic control, human-machine interface design, software, hardware, and integration between software and hardware, a high-quality personal desktop liquid-metal printer that is ready for mass production in industry was fabricated. Its basic features and important technical mechanisms are explained in this paper, along with demonstrations of several possible consumer end-uses for making functional devices such as li ght-emitting diode(LED) displays. This liquid-metal printer is an automatic, easyto-use, and low-cost personal electronics manufacturing tool with many possible applications. This paper discusses important roles that the new machine may play for a group of emerging needs. The prospective future of this cuttingedge technology is outlined, along with a comparative interpretation of several historical printing methods. This desktop liquid-metal printer is expected to become a basic electronics manufacturing tool for a wide variety of emerging practices in the academic realm, in industry, and in education as well as for individual end-users in the near future.
文摘In order to overcome the shortcomings of low-cost anti-oxidation conductive ink and its preparation method in the field of printing electronics, core-shell coated Cu@Ag nanoparticles were used to prepare conductive ink, and a printed circuit was obtained by inkjet printing. Copper nanoparticles were prepared by a chemical reduction method and then coated with Cu@Ag particles by a copper-based self-catalytic reaction. Conductive ink was prepared by ball milling and dispersion and printed on PI film to form a conductive coating. After characterization and analysis, the particle size and dispersion of the obtained Cu@Ag meet the requirements and can be stored stably under normal atmospheric conditions. The resistivity of the conductive film sintered at 300˚C is only 10.6 μΩ<span style="font-size:10.0pt;font-family:"">∙</span>cm.
基金support ofthe Boeing Fund for the Advancement of Undergraduate Research Excellence in Engineering.
文摘Achieving simultaneous high conductivity and mechanical durability in printed flexible electronics remains a central challenge.Here we report a systematic investigation of silver nanoparticle(AgNP)size effects on film performance using a pH-mediated synthesis that decouples particle size from organic content.This strategy enables direct assessment of size-dependent sintering and mechanical behaviors,previously obscured by varied polymer concentrations of traditional size control methods.With consistent organic content,AgNPs of smaller size demonstrated more effective sintering,forming denser and more cohesive microstructures,contrary to prior reports with varied organic concentration.This yielded highly conductive films with resistivities as low as 2.34μΩcm,approaching bulk silver.Additionally,electrohydrodynamic(EHD)printing of these inks produced flexible circuits with significantly improved mechanical resilience.The resistance of a printed pattern remained stable over 1,000 bending cycles at a 2.9 mm radius and increased by only 56.7%after 50,000 cycles,with no visible microstructural cracking.
基金based by the Office of Research and Sponsored Projects at The University of Texas at El Paso
文摘It has been more than three decades since stereolithography began to emerge in various forms of additive manufacturing and 3D printing. Today these technologies are proliferating worldwide in various forms of advanced manufacturing. The largest segment of the 3D printing market today involves various polymer component fabrications, particularly complex structures not attainable by other manufacturing methods.Conventional printer head systems have also been adapted to selectively print various speciated human cells and special molecules in attempts to construct human organs, beginning with skin and various tissue patches. These efforts are discussed along with metal and alloy fabrication of a variety of implant and bone replacement components by creating powder layers, which are selectively melted into complex forms（such as foams and other open-cellular structures） using laser and electron beams directed by CAD software. Efforts to create a ＂living implant＂ by bone ingrowth and eventual vascularization within these implants will be discussed briefly. Novel printer heads for direct metal droplet deposition as in other 3D printing systems are briefly described since these concepts will allow for the eventual fabrication of very large and complex products, including automotive and aerospace structures and components.
文摘In a rational exercise, in the present paper it is extrapolated how the development of ICTs （information and communication technologies） and the incipient technological development of additive manufacturing has the potential to change our society. In the following, it is analyzing the evolution of man over physical matter and how this has shaped our society. The main milestones or key stages in history that have marked a transcendental change in the human-machine-environment relationship have been identified and consequently have led us to ask ourselves： What is next, how far are we, and what are we capable of printing？ In an attempt to identify the current state of the art, highlighting the possibilities those additive technologies can offer.
基金supported by the National Program on Key Basic Research Project(No.2015CB351901)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA09020201)the National Science Foundation of China(Nos.51603227,51603228)
文摘In this paper, a flexible and stretchable circuit has been fabricated by the printing method based on Ag NWs/PDMS composite. The randomly oriented Ag NWs were buried in PDMS to form a conductive and stretchable electrode. Stable conductivity was achieved with a large range of tensile strain（0-50%） after the initial stretching/releasing cycle. The stable electrical response is due to the buckling of the Ag NWs/PDMS composite layer. Furthermore, printed stretchable circuits integrated with commercial ICs have been demonstrated for wearable applications.
文摘We combined lightweight and mechanically flexible printed transistors and actuators with a paper unmanned aerial vehicle(UAV)glider prototype to demonstrate electrically controlled glide path modification in a lightweight,disposable UAV system.The integration of lightweight and mechanically flexible electronics that is offered by printed electronics is uniquely attractive in this regard because it enables flight control in an inexpensive,disposable,and easily integrated system.Here,we demonstrate electroactive polymer(EAP)actuators that are directly printed into paper that act as steering elements for low cost,lightweight paper UAVs.We drive these actuators by using ion gel-gated organic thin film transistors(OTFTs)that are ideally suited as drive transistors for these actuators in terms of drive current and frequency requirements.By using a printing-based fabrication process on a paper glider,we are able to deliver an attractive path to the realization of inexpensive UAVs for ubiquitous sensing and monitoring flight applications.
基金the Philippines’Department of Science and Technology-Engineering Research and Development for Technology program,the Intelligent Systems Laboratory and the iNano Laboratory of the De La Salle University,the Fundação para a Ciência e a Tecnologia(FCT)for funding MARE(Marine and Environmental Sciences Centre,UIDB/04292/2020 and UIDB/04292/2020)ARNET(Aquatic Research Infrastructure Network Associated Laboratory,LA/P/0069/2020)B.Duarte researcher contract(CEECIND/00511/2017).
文摘Nitrate is the primary water-soluble macronutrient essential for plant growth that is converted from excess fish feeds,fish effluents,and degrading biomaterials on the aquaponic pond floor,and when aquacultural malpractices occur,large amounts of it retain in the water system causing increase rate in eutrophication and toxifies fish and aquaculture plants.Recent nitrate sensor prototypes still require performing the additional steps of water sample deionization and dilution and were constructed with expensive materials.In response to the challenge of sensor enhancement and aquaponic water quality monitoring,this study developed sensitive,repeatable,and reproducible screen-printed graphite electrodes on polyvinyl chloride and parchment paper substrates with silver as electrode material and 60:40 graphite powder:nail polish formulated conductive ink for electrical traces,integrated with 9-gene genetic expression model as a function of peak anodic current and electrochemical test time for nitrate concentration prediction that is embedded into low-power Arduino ESP32 for in situ nitrate sensing in aquaponic pond water.Five SPE electrical traces were designed on the two types of substrates.Scanning electron microscopy with energy dispersive X-ray confirmed the electrode surface morphology.Electrochemical cyclic voltammetry using 10 to 100 mg/L KNO3 and water from three-depth regions of the actual pond established the electrochemical test time(10.5 s)and electrode potential(0.135 V)protocol necessary to produce peak current that corresponds to the strength of nitrate ions during redox.The findings from in situ testing revealed that the proposed sensors have strong linear predictions(R2=0.968 MSE=1.659 for nSPEv and R2=0.966 MSE=4.697 for nSPEp)in the range of 10 to 100 mg/L and best detection limit of 3.15μg/L,which are comparable to other sensors of more complex construction.The developed three-electrode electrochemical nitrate sensor confirms that it is reliable for both biosensing in controlled solutions and in situ aquaponic pond water systems.
基金supported by the National Key Basic Research Program of China(Nos.2014CB648300,2017YFB0404501)the National Natural Science Foundation of China(Nos.21422402,21674050)+8 种基金the Natural Science Foundation of Jiangsu Province(Nos.BK20140060,BK20130037,BK20140865,BM2012010)the Program for Jiangsu Specially-Appointed Professors(No.RK030STP15001)the Program for New Century Excellent Talents in University(No.NCET-13-0872)the NUPT"1311 Project"and Scientific Foundation(Nos.NY213119,NY213169)the Synergetic Innovation Center for Organic Electronics and Information Displays,the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Leading Talent of Technological Innovation of National Ten Thousands Talents Program of Chinathe Excellent Scientific and Technological Innovative Teams of Jiangsu Higher Education Institutions(No.TJ217038)the Program for Graduate Students Research and Innovation of Jiangsu Province(No.KYZZ16-0253)the 333 Project of Jiangsu Province(Nos.BRA2017402,BRA2015374)
文摘In this work, a simple methodology was developed to enhance the patterning resolution of inkjet printing, involving process optimization as well as substrate modification and treatment. The line width of the inkjetprinted silver lines was successfully reduced to 1/3 of the original value using this methodology. Large-area flexible circuits with delicate patterns and good morphology were thus fabricated. The resultant flexible circuits showed excellent electrical conductivity as low as 4.5 Ω/□ and strong tolerance to mechanical bending. The simple methodology is also applicable to substrates with various wettability, which suggests a general strategy to enhance the printing quality of inkjet printing for manufacturing high-performance large-area flexible electronics.
基金National Research Foundation of Korea,Grant/Award Numbers:RS-2024-00352352,NRF-2022R1A4A3032923South Korean Ministry of Trade,Industry and Energy,Grant/Award Number:RS-2022-00154781National Research Council of Science&Technology,Grant/Award Number:CRC230231-000。
文摘Continuously printable electronics have the significant advantage of being efficient for fabricating conductive polymer composites;however,the precise tailoring of the 3D hierarchical morphology of conductive nanocomposites in a simple dripping step remains challenging.Here,we introduce a one-step direct printing technique to construct diverse microdome morphologies influenced by the interfacial Marangoni effect and nanoparticle interactions.Using a jet dispenser for continuous processing,we effectively fabricated a soft epidermislike e-skin containing 64 densely arrayed pressure sensing pixels with a hierarchical dome array for enhanced linearity and ultrasensitivity.The e-skin has 36 temperature-sensing pixels in the outer layer,with a shield-shaped dome that is insensitive to pressure stimuli.Our prosthetic finger inserted with the printed sensor arrays was capable of ultragentle detection and manipulation,such as stably holding a fragile biscuit,using a soft dropper to elaborately produce water droplets and harvesting soft fruits;these activities are challenging for existing high-sensitivity tactile sensors.
