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
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
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
Printed circuit boards(PCBs)are representative composite materials,and their high-quality drilling machining remains a persistent challenge in the industry.The finishing of the cutting edge of a microdrill is crucial ...Printed circuit boards(PCBs)are representative composite materials,and their high-quality drilling machining remains a persistent challenge in the industry.The finishing of the cutting edge of a microdrill is crucial to drill performance in machining fine-quality holes with a prolonged tool life.The miniature size involving submicron scale geometric dimensions,a complex flute shape,and low fracture toughness makes the cutting edge of microdrills susceptible to breakage and has been the primary limiting factor in edge preparation for microdrills.In this study,a newly developed cutting edge preparation method for microdrills was tested experimentally on electronic printed circuit boards.The proposed method,namely,shear thickening polishing,limited the cutting edge burrs and chipping on the cutting edge,and this in turn transformed the cutting edge’s radius from being sharp to smooth.Moreover,the edge–edge radius could be regulated by adjusting the processing time.PCB drilling experiments were conducted to investigate the influence of different cutting edge radii on wear,hole position accuracy,nail head value,and hole wall roughness.The proposed approach showed 20%enhancement in hole position accuracy,33%reduction in the nail head value,and 19%reduction in hole wall roughness compared with the original microdrill.However,a threshold is needed;without it,excessive shear thickening polishing will result in a blunt edge,which may accelerate the wear of the microdrill.Wear was identified as the primary factor that reduced hole quality.The study indicates that in printed circuit board machining,microdrills should effectively eliminate grinding defects and maintain the sharpness of the cutting edge as much as possible to obtain excellent drilling quality.Overall,shear thickening polishing is a promising method for cutting edge preparation of microdrills.Further research and optimization can lead to additional improvements in microdrill performance and contribute to the continued advancement of printed circuit board manufacturing.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
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 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
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
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
Pulsed electrohydrodynamic printing (EHDP) is used to fabricate conductive silver patterns with micrometer resolution. The silver ink pendant experiences swelling, pulsation, and ejection under an applied pulse volt...Pulsed electrohydrodynamic printing (EHDP) is used to fabricate conductive silver patterns with micrometer resolution. The silver ink pendant experiences swelling, pulsation, and ejection under an applied pulse voltage of 20 Hz. The droplet deposi- tion frequency is equal to the applied voltage frequency so that the EHDP can deposit silver ink on demand. A low applied voltage favors uniform and non-scattering silver patterns while a high applied voltage results in ink scattering. Discrete drop- lets with 45-55 gm in diameter and continuous tracks with 60 gm in width are generated by using a ll0-i.tm-cailber nozzle. The feature size of deposited patterns is about half of the nozzle caliber, and a finer resolution can be achieved with the intro- duction of smaller nozzle calibers. Furthermore, the appropriate curing condition is investigated for sufficient combustion of ink solvent. The minimum resistivity of 3.3 gf~ cm is demonstrated for a continuous track cured at 200~C for 10 min. Eventu- ally, several passive electrical components, such as coated resistors, interdigitated capacitors (6 pF), and spiral inductors (0.6 gH), are successfully fabricated.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
Integrating the topology design and printing method offers a promising methodology to realize large stretchability for interconnects.Herein,eco-friendly and waterbased Ag nanowires(NWs)inks were formulated and used fo...Integrating the topology design and printing method offers a promising methodology to realize large stretchability for interconnects.Herein,eco-friendly and waterbased Ag nanowires(NWs)inks were formulated and used for screen-printing highly stretchable and flexible interconnects on a large area(more than 335 mm x 175 mm).The stretchability of the interconnects was realized by introducing kirigami topology structures.The topology designed models were established to simulate the influence of kirigami patterns on wire compliance and to estimate the maximum stretchability via finite element analysis(FEA).The mechanic mechanism results demonstrate that an increase of the wave numbers results in larger stretchability,and the rectangular type of wave shows better stretchability than the zigzag and sine structures.Comparatively,the electrical and mechanical properties of the interconnects were measured and analyzed,and the experimental results were consistent with FEA.The electric conductivity of the interconnects is stable at^10,427 S cm-1 even after 1000 cycles of 15.83 mm radius bending,280%stretching and 200%twisting-stretching deformation,demonstrating outstanding mechanical reliability of the interconnects.The topology designed interconnects have been applied in stretchable flexible light-emitting diode,indicating their broad application prospects in next-generation stretchable electronics.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 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
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
With the rapid development of deep space exploration and commercial flight, a series of tough scientific and technological challenges were raised, which urgently require ever advanced technologies to tackle with. Rece...With the rapid development of deep space exploration and commercial flight, a series of tough scientific and technological challenges were raised, which urgently require ever advanced technologies to tackle with. Recently, liquid metals, as a kind of newly emerging functional material, are attracting various attention and many breakthroughs have been made on earth. Such a scientific trend also suggests promising approaches for solving those extreme challenges in space environment. To fulfill the increasing needs thus involved, this article is dedicated to systematically introducing liquid metal material and its related disciplines into space science and technology. Firstly, existing application of liquid metal cooling for space nuclear power was summarized. Then, some potential space practices were tentatively put forward, such as liquid metal thermal interface medium,liquid metal phase change material, liquid metal convection cooling, metal alloy thermal storage, liquid metal electromagnetic shielding and liquid metal electronic printing. Fundamental as well as practical issues that would differ with earth were interpreted. Finally, potential liquid metal space experiments were proposed to investigate the liquid metal hydrodynamic characteristic, wettability and phase change mechanism in space physical environment. Overall, liquid metal enabled space science and technology investigation will not only help efficiently solve the current and future space technological problems, but also aid to stimulate the advancement of liquid metal space material science.展开更多
Surface tension plays a core role in dominating various surface and interface phenomena. For liquid metals with high melting temperature, a profound understanding of the behaviors of surface tension is crucial in indu...Surface tension plays a core role in dominating various surface and interface phenomena. For liquid metals with high melting temperature, a profound understanding of the behaviors of surface tension is crucial in industrial processes such as casting, welding, and solidification, etc. Recently, the room temperature liquid metal (RTLM) mainly composed of gallium-based alloys has caused widespread concerns due to its increasingly realized unique virtues. The surface properties of such materials are rather vital in nearly all applications involved from chip cooling, thermal energy harvesting, hydrogen generation, shape changeable soft machines, printed electronics to 3D fabrication, etc. owing to its pretty large surface tension of approximately 700 mN/m. In order to promote the research of surface tension of RTLM, this paper is dedicated to present an overview on the roles and mechanisms of surface tension of liquid metal and summarize the latest progresses on the understanding of the basic knowledge, theories, influencing factors and experimental measure- ment methods clarified so far. As a practical technique to regulate the surface tension of RTLM, the fimdamental principles and applications of electrowetting are also interpreted. Moreover, the unique phenomena of RTLM surface tension issues such as surface tension driven self- actuation, modified wettability on various substrates and the functions of oxides are discussed to give an insight into the acting mechanism of surface tension. Furthermore, future directions worthy of pursuing are pointed out.展开更多
Graphene oxide and silver nanowires were bar coated onto polyethylene terephthalate (PET) substrates and then welded using an ultraviolet (UV)-assisted flash light irradiation process to achieve both high electric...Graphene oxide and silver nanowires were bar coated onto polyethylene terephthalate (PET) substrates and then welded using an ultraviolet (UV)-assisted flash light irradiation process to achieve both high electrical conductivity and low haze. The irradiation process connected adjacent silver nanowires by welding, while simultaneously reducing the graphene oxide to graphene. This process was performed using a custom W-assisted flash light welding system at room temperature under ambient conditions and was extremely rapid, with processing time of several milliseconds. The effects of varying the weight fractions of the silver nanowires and graphene oxide and of varying the W-assisted flash light welding conditions (light energy and pulse duration) were investigated. The surface morphologies of the welded silver nanowire/graphene films were analyzed using scanning electron microscopy. Optical characterizations, including transmittance and haze measurements, were also conducted using a spectrophotometer. To test their resistance to oxidation, the welded silver nanowire/graphene films were subjected to high temperature in a furnace (100 ℃), and their sheet resistances were measured every hour. The flash light welding process was found to yield silver nanowire/graphene films with high oxidation resistance, high conductivity (14.35 Ω·sq-1), high transmittance (93.46%), and low haze (0.9%). This material showed uniform temperature distribution when applied as a resistive heating film.展开更多
Fully printed perovskite solar cells(PSCs)were fabricated in air with all constituent layers,except for electrodes,deposited by the blade coating technique.The PSCs incorporated,for the first time,a nanometer-thick pr...Fully printed perovskite solar cells(PSCs)were fabricated in air with all constituent layers,except for electrodes,deposited by the blade coating technique.The PSCs incorporated,for the first time,a nanometer-thick printed bathocuproine(BCP)hole blocking buffer using blade coating and deposited at relative humidity up to 50%.The PSCs with a p-i-n structure(glass/indium tin oxide(ITO)/poly(3,4-ethylenedioxythiophene)polystyrene sulfonate(PEDOT:PSS)/CH_(3)NH_(3)Pbl_(3)/[6,6]-phenyl-C_(61)-butyric acid methyl ester(PCBM)/BCP/Ag)delivered a maximum power conversion efficiency(PCE)of 14.9%on an active area of 0.5 cm^(2)when measured under standard test conditions.The PSCs with a blade coated BCP delivered performance of 10%and 63%higher(in relative terms)than those incorporating a spin coated BCP or without any BCP film,respectively.The atomic force microscopy(AFM)showed that blade coated films were more homogeneous and acted also as a surface planarizer leading to a reduction of roughness which improved BCP/Ag interface lowering charge recombination.The demonstration of 15%efficient devices with all constituent layers,including nanometer-thick BCP(〜10 nm),deposited by blade coating in air,demonstrates a route for industrialization of this technology.展开更多
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.
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.
基金support from the National Natural Science Foundation of China(Grant No.52175441)the Natural Science Foundation of Zhejiang Province,China(Grant No.LD22E050010)+4 种基金the travel scholarship from the China Scholarship Council(Grant No.202208330333)for secondment of Jiahuan Wang at London South Bank University(LSBU)for working closely with Prof.GoelSaurav Goel would like to acknowledge the funding support from UK Research and Innovation,UKRI(Grant Nos.EP/S036180/1 and EP/T024607/1)the feasibility study awards to LSBU from the UKRI National Interdisciplinary Circular Economy Hub(Grant No.EP/V029746/1)Transforming the Foundation Industries:A Network+(Grant No.EP/V026402/1)the International Exchange Cost Share Award by the Royal Society(Grant No.IEC\NSFC\223536).This work accessed the supercomputing service(Isambard-AI,Bristol,UK)via the Resource Allocation Panel and Kittrick(LSBU)-based computational resources.
文摘Printed circuit boards(PCBs)are representative composite materials,and their high-quality drilling machining remains a persistent challenge in the industry.The finishing of the cutting edge of a microdrill is crucial to drill performance in machining fine-quality holes with a prolonged tool life.The miniature size involving submicron scale geometric dimensions,a complex flute shape,and low fracture toughness makes the cutting edge of microdrills susceptible to breakage and has been the primary limiting factor in edge preparation for microdrills.In this study,a newly developed cutting edge preparation method for microdrills was tested experimentally on electronic printed circuit boards.The proposed method,namely,shear thickening polishing,limited the cutting edge burrs and chipping on the cutting edge,and this in turn transformed the cutting edge’s radius from being sharp to smooth.Moreover,the edge–edge radius could be regulated by adjusting the processing time.PCB drilling experiments were conducted to investigate the influence of different cutting edge radii on wear,hole position accuracy,nail head value,and hole wall roughness.The proposed approach showed 20%enhancement in hole position accuracy,33%reduction in the nail head value,and 19%reduction in hole wall roughness compared with the original microdrill.However,a threshold is needed;without it,excessive shear thickening polishing will result in a blunt edge,which may accelerate the wear of the microdrill.Wear was identified as the primary factor that reduced hole quality.The study indicates that in printed circuit board machining,microdrills should effectively eliminate grinding defects and maintain the sharpness of the cutting edge as much as possible to obtain excellent drilling quality.Overall,shear thickening polishing is a promising method for cutting edge preparation of microdrills.Further research and optimization can lead to additional improvements in microdrill performance and contribute to the continued advancement of printed circuit board manufacturing.
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.
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.
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 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 the National Natural Science Foundation of China (Grant No. 51035002)the Key Project of Chinese Ministry of Edu-cation (Grant No. 708055)the Fundamental Research Funds for the Central Universities (Grant No. 2010121039)
文摘Pulsed electrohydrodynamic printing (EHDP) is used to fabricate conductive silver patterns with micrometer resolution. The silver ink pendant experiences swelling, pulsation, and ejection under an applied pulse voltage of 20 Hz. The droplet deposi- tion frequency is equal to the applied voltage frequency so that the EHDP can deposit silver ink on demand. A low applied voltage favors uniform and non-scattering silver patterns while a high applied voltage results in ink scattering. Discrete drop- lets with 45-55 gm in diameter and continuous tracks with 60 gm in width are generated by using a ll0-i.tm-cailber nozzle. The feature size of deposited patterns is about half of the nozzle caliber, and a finer resolution can be achieved with the intro- duction of smaller nozzle calibers. Furthermore, the appropriate curing condition is investigated for sufficient combustion of ink solvent. The minimum resistivity of 3.3 gf~ cm is demonstrated for a continuous track cured at 200~C for 10 min. Eventu- ally, several passive electrical components, such as coated resistors, interdigitated capacitors (6 pF), and spiral inductors (0.6 gH), are successfully fabricated.
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supported by the National Natural Science Foundation of China(51471121)the Basic Research Plan Program of Shenzhen City(JCYJ20170303170426117)+2 种基金the Natural Science Foundation of Jiangsu Province(BK20160383)the Fundamental Research Funds for the Central Universities(2042018kf203)Wuhan University
文摘Integrating the topology design and printing method offers a promising methodology to realize large stretchability for interconnects.Herein,eco-friendly and waterbased Ag nanowires(NWs)inks were formulated and used for screen-printing highly stretchable and flexible interconnects on a large area(more than 335 mm x 175 mm).The stretchability of the interconnects was realized by introducing kirigami topology structures.The topology designed models were established to simulate the influence of kirigami patterns on wire compliance and to estimate the maximum stretchability via finite element analysis(FEA).The mechanic mechanism results demonstrate that an increase of the wave numbers results in larger stretchability,and the rectangular type of wave shows better stretchability than the zigzag and sine structures.Comparatively,the electrical and mechanical properties of the interconnects were measured and analyzed,and the experimental results were consistent with FEA.The electric conductivity of the interconnects is stable at^10,427 S cm-1 even after 1000 cycles of 15.83 mm radius bending,280%stretching and 200%twisting-stretching deformation,demonstrating outstanding mechanical reliability of the interconnects.The topology designed interconnects have been applied in stretchable flexible light-emitting diode,indicating their broad application prospects in next-generation stretchable electronics.
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.
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 by the Key Project of the National Natural Science Foundation of China (Grant No. 91748206)the Frontier Project of the Chinese Academy of Sciences and Dean’s Research Funding。
文摘With the rapid development of deep space exploration and commercial flight, a series of tough scientific and technological challenges were raised, which urgently require ever advanced technologies to tackle with. Recently, liquid metals, as a kind of newly emerging functional material, are attracting various attention and many breakthroughs have been made on earth. Such a scientific trend also suggests promising approaches for solving those extreme challenges in space environment. To fulfill the increasing needs thus involved, this article is dedicated to systematically introducing liquid metal material and its related disciplines into space science and technology. Firstly, existing application of liquid metal cooling for space nuclear power was summarized. Then, some potential space practices were tentatively put forward, such as liquid metal thermal interface medium,liquid metal phase change material, liquid metal convection cooling, metal alloy thermal storage, liquid metal electromagnetic shielding and liquid metal electronic printing. Fundamental as well as practical issues that would differ with earth were interpreted. Finally, potential liquid metal space experiments were proposed to investigate the liquid metal hydrodynamic characteristic, wettability and phase change mechanism in space physical environment. Overall, liquid metal enabled space science and technology investigation will not only help efficiently solve the current and future space technological problems, but also aid to stimulate the advancement of liquid metal space material science.
文摘Surface tension plays a core role in dominating various surface and interface phenomena. For liquid metals with high melting temperature, a profound understanding of the behaviors of surface tension is crucial in industrial processes such as casting, welding, and solidification, etc. Recently, the room temperature liquid metal (RTLM) mainly composed of gallium-based alloys has caused widespread concerns due to its increasingly realized unique virtues. The surface properties of such materials are rather vital in nearly all applications involved from chip cooling, thermal energy harvesting, hydrogen generation, shape changeable soft machines, printed electronics to 3D fabrication, etc. owing to its pretty large surface tension of approximately 700 mN/m. In order to promote the research of surface tension of RTLM, this paper is dedicated to present an overview on the roles and mechanisms of surface tension of liquid metal and summarize the latest progresses on the understanding of the basic knowledge, theories, influencing factors and experimental measure- ment methods clarified so far. As a practical technique to regulate the surface tension of RTLM, the fimdamental principles and applications of electrowetting are also interpreted. Moreover, the unique phenomena of RTLM surface tension issues such as surface tension driven self- actuation, modified wettability on various substrates and the functions of oxides are discussed to give an insight into the acting mechanism of surface tension. Furthermore, future directions worthy of pursuing are pointed out.
文摘Graphene oxide and silver nanowires were bar coated onto polyethylene terephthalate (PET) substrates and then welded using an ultraviolet (UV)-assisted flash light irradiation process to achieve both high electrical conductivity and low haze. The irradiation process connected adjacent silver nanowires by welding, while simultaneously reducing the graphene oxide to graphene. This process was performed using a custom W-assisted flash light welding system at room temperature under ambient conditions and was extremely rapid, with processing time of several milliseconds. The effects of varying the weight fractions of the silver nanowires and graphene oxide and of varying the W-assisted flash light welding conditions (light energy and pulse duration) were investigated. The surface morphologies of the welded silver nanowire/graphene films were analyzed using scanning electron microscopy. Optical characterizations, including transmittance and haze measurements, were also conducted using a spectrophotometer. To test their resistance to oxidation, the welded silver nanowire/graphene films were subjected to high temperature in a furnace (100 ℃), and their sheet resistances were measured every hour. The flash light welding process was found to yield silver nanowire/graphene films with high oxidation resistance, high conductivity (14.35 Ω·sq-1), high transmittance (93.46%), and low haze (0.9%). This material showed uniform temperature distribution when applied as a resistive heating film.
基金We acknow ledge Petroleo Brasileiro S.A.(PETROBRAS)under the project“Research and Development of Perovskite form ulations for production of printed photovoltaic cells and modulesM for funding.S.C.-H and T.M.B.acknowledge to have received funding from Departamen to del Huila’s Scholarship Program No.677 from Huila,Colombia,the European Unions H orizon 2020 research and innovation program under grant agreement no.763989 APOLO,Lazio Region“Gruppi di Ricerca”under project no.85-2017-15373(SIROH)according to L.R.Lazio 13/08,and the Italian Ministry o f University and Research(MIUR)through the PRIN2017 BOOSTER(project n.2017YXX8AZ)grant.This publication reflects only the authors' views and the funding agencies are not liable for any use that may be made of the inform ation contained therein.We thank to Gabriela Amorim for solar cell encapsulation.We thank engineering departm ent at CSEM Brasil for developing the nitrogen blower system.We thank to Centro de Microscopia,Laboratorio de Caracterizacao e de Processam ento de Nanom ateriais from Federal University of M inas Gerais,for providing the experimental facilities and Prof.Wagner da Nova Mussel for XRD results.
文摘Fully printed perovskite solar cells(PSCs)were fabricated in air with all constituent layers,except for electrodes,deposited by the blade coating technique.The PSCs incorporated,for the first time,a nanometer-thick printed bathocuproine(BCP)hole blocking buffer using blade coating and deposited at relative humidity up to 50%.The PSCs with a p-i-n structure(glass/indium tin oxide(ITO)/poly(3,4-ethylenedioxythiophene)polystyrene sulfonate(PEDOT:PSS)/CH_(3)NH_(3)Pbl_(3)/[6,6]-phenyl-C_(61)-butyric acid methyl ester(PCBM)/BCP/Ag)delivered a maximum power conversion efficiency(PCE)of 14.9%on an active area of 0.5 cm^(2)when measured under standard test conditions.The PSCs with a blade coated BCP delivered performance of 10%and 63%higher(in relative terms)than those incorporating a spin coated BCP or without any BCP film,respectively.The atomic force microscopy(AFM)showed that blade coated films were more homogeneous and acted also as a surface planarizer leading to a reduction of roughness which improved BCP/Ag interface lowering charge recombination.The demonstration of 15%efficient devices with all constituent layers,including nanometer-thick BCP(〜10 nm),deposited by blade coating in air,demonstrates a route for industrialization of this technology.