Super-fine electrohydrodynamic inkjet(SIJ)printing of perovskite nanocrystal(PNC)colloid ink exhibits significant potential in the fabrication of high-resolution color conversion microstructures arrays for fullcolor m...Super-fine electrohydrodynamic inkjet(SIJ)printing of perovskite nanocrystal(PNC)colloid ink exhibits significant potential in the fabrication of high-resolution color conversion microstructures arrays for fullcolor micro-LED displays.However,the impact of solvent on both the printing process and the morphology of SIJ-printed PNC color conversion microstructures remains underexplored.In this study,we prepared samples of CsPbBr3PNC colloid inks in various solvents and investigated the solvent's impact on SIJ printed PNC microstructures.Our findings reveal that the boiling point of the solvent is crucial to the SIJ printing process of PNC colloid inks.Only does the boiling point of the solvent fall in the optimal range,the regular positioned,micron-scaled,conical PNC microstructures can be successfully printed.Below this optimal range,the ink is unable to be ejected from the nozzle;while above this range,irregular positioned microstructures with nanoscale height and coffee-ring-like morphology are produced.Based on these observations,high-resolution color conversion PNC microstructures were effectively prepared using SIJ printing of PNC colloid ink dispersed in dimethylbenzene solvent.展开更多
As an accurate 2D/3D fabrication tool,inkjet printing technology has great potential in preparation of micro electronic devices.The morphology of droplets produced by the inkjet printer has a great impact on the accur...As an accurate 2D/3D fabrication tool,inkjet printing technology has great potential in preparation of micro electronic devices.The morphology of droplets produced by the inkjet printer has a great impact on the accuracy of deposition.In this study,the drop-on-demand(DoD)inkjet simulation model was established,and the accuracy of the simulation model was verified by corresponding experiments.The simulation result shows that the velocity of the droplet front and tail,as well as the time to disconnect from the nozzle is mainly affected by density(ρ),viscosity(μ)and surface tension(σ)of droplets.When the liquid filament is about to disconnect from the nozzle,the filament length and filament front velocity are found to have a linear correlation withσ/ρμand ln(ρ/(μσ1/2)).展开更多
Inkjet printing has emerged as a potential solution processing method for large-area patterned films.During inkjet printing,a single droplet without satellite droplet is required for high-quality film.Herein,we propos...Inkjet printing has emerged as a potential solution processing method for large-area patterned films.During inkjet printing,a single droplet without satellite droplet is required for high-quality film.Herein,we propose a strategy for obtaining a single droplet by adjusting the reduced concentration(c/c^(*),where c^(*)is the critical overlap concentration)in the range of 1.0-1.5.Droplet formation can be categorized into three distinct regimes:(1)c/c^(*)<1.0,satellite droplet;(2)c/c^(*)=1.0-1.5,single droplet;(3)c/c^(*)>2.0,no droplet.Furthermore,an inertial-capillary balance led to the 2/3-power scaling of the minimum radius with time for the solutions of c/c^(*)<1.0.However,for the solutions of c/c^(*)=1.0-1.5,the ligament radius decreased exponentially with time.Moreover,the Weissenberg number was higher than the critical value of 0.5,indicating that the polymer chains underwent coil-stretch transition.The viscoelastic-capillary balance dominated instead of the inertial-capillary balance.The resulting viscoelastic resistance reduced the length of the ligament and increased the velocity difference between the satellite and main droplets.Consequently,a single droplet was formed.In addition,the law can be successfully generalized to various molecular weights,molecular structures and solvents.展开更多
Inkjet 3D printing has potential in the additive manufacturing of electronic circuits and devices.However,inks that can be used for printing layers with T5%>300℃ or hardness>200 MPa have been rarely reported.Cy...Inkjet 3D printing has potential in the additive manufacturing of electronic circuits and devices.However,inks that can be used for printing layers with T5%>300℃ or hardness>200 MPa have been rarely reported.Cyanate ester(CE)polymers have excellent thermal stability,high strength,and low shrinkage compared to other common dielectric inks for inkjet 3D printing,but cannot be quickly shaped by ultraviolet(UV)irradiation or thermal treatment.Combining CEs with UV-curable monomers may be a possible way to accelerate crosslinking,but there are challenges from the adverse effects of the dilution of both monomers.In this study,dielectric inks with acrylate and cyanate moieties were developed.The low viscosity and surface tension of the CE precursor(Bisphenol E cyanate ester)were combined with photocurable acrylate diluent monomers and cross-linker to realize an ink suitable for inkjet 3D printing.An internal dual three-dimensional cross-linked network structure resin was prepared by a combination of photocuring and thermal curing with T5%up to 326.69℃,hardness up to 431.84 MPa,dielectric constant of 2.70 at 8 GHz,and shrinkage of 1.64%.The developed dielectric inks can be applied to the 3D printing of printed circuit boards and other electronic devices that require dielectric properties.展开更多
Zn anode-based electrochromic devices(ZECDs)stand out as a highly promising technology in the upcoming era of multifunctional electronic devices,offering a blend of electrochromic capabilities and energy storage funct...Zn anode-based electrochromic devices(ZECDs)stand out as a highly promising technology in the upcoming era of multifunctional electronic devices,offering a blend of electrochromic capabilities and energy storage functions within a single transparent platform.However,significant challenges persist in achieving efficient patterning,ensuring long-term stability,and fast color-switching kinetics for these devices.In this study,heterogeneous tungsten oxide nanowires(W_(17)O_(47)/Na_(0.1)WO_(3),WNOs)are formulated into inkjet printing ink to assemble patternable ZECDs.The heterogeneous electrode structure of WNO enables a highly capacitive-controlled mechanism that promotes fast electrochromic/electrochemical behavior.Notably,by utilizing a three-dimensional MXene mesh modified substrate,the inkjet-printed ZECDs exhibit a wide optical modulation range of 69.13%,rapid color-changing kinetics(t_(c)=4.1 s,t_(b)=5.4 s),and highly reversible capacities of 70 mAh cm^(-2)over 1000 cycles.This scalable strategy develops the patterned electrodes with a wide optical modulation range and substantial energy storage properties,offering promising prospects for their application in next-generation smart electronics.展开更多
Polymer thin film with uniform thickness and flat surface profile is the key point for polymer light emitting diodes(PLEDs) by inkjet printing. However, the coffee ring effect is usually observed due to the mismatch b...Polymer thin film with uniform thickness and flat surface profile is the key point for polymer light emitting diodes(PLEDs) by inkjet printing. However, the coffee ring effect is usually observed due to the mismatch between the evaporation of the solvent and the decrease of solution volume, which promotes the formation of radial flow from the interior of the drop to the edge. In this paper, coffee ring effects of inkjet printed poly(spirobifluorene) films were proposed to be restrained by decreasing capillary force by adding co-solvent with high boiling point and high viscosity to the main solvent. The low evaporation rate of the co-solvent can reduce the driving force of the radial flow; meanwhile the high viscosity of the co-solvent can increase the resistance of the radial flow. Thus, polymer films with improve uniformity can be obtained due to the suppression of the radial flow. The device performance was greatly improved under the condition of proper film thickness and film uniformity and the maximum luminous efficiency of devices with inkjet printed poly(spirobifluorene) can reach 80% of the spin-coated devices.展开更多
By means of inkjet printing technique, flexible and all-solid-state micro-supercapacitors(MSCs) were fabricated with carbon-based hybrid ink composed of graphene oxide(GO,98.0vol.%) ink and commercial pen ink(2.0vol.%...By means of inkjet printing technique, flexible and all-solid-state micro-supercapacitors(MSCs) were fabricated with carbon-based hybrid ink composed of graphene oxide(GO,98.0vol.%) ink and commercial pen ink(2.0vol.%). A small amount of commercial pen ink was added to effectively reduce the agglomeration of theGO sheets during solvent evaporation and the following reduction processes in which the presence of graphite carbon nanoparticles served as nano-spacer to separate GO sheets. The printed device fabricated using the hybrid ink,combined with the binder-free microelectrodes and interdigital microelectrode configuration, exhibits nearly 780%enhancement in areal capacitance compared with that of pure GO ink. It also shows excellent flexibility and cycling stability with nearly 100% retention of the areal capacitance after 10,000 cycles. The all-solid-state device can be optionally connected in series or in parallel to meet the voltage and capacity requirements for a given application.This work demonstrates a promising future of the carbonbased hybrid ink for directly large-scale inkjet printing MSCs for disposable energy storage devices.展开更多
In order to build a ceramic component by inkjet printing, the object must be fabricated through the interaction and solidification of drops, typically in the range of 10–100 p L. In order to achieve this goal, stable...In order to build a ceramic component by inkjet printing, the object must be fabricated through the interaction and solidification of drops, typically in the range of 10–100 p L. In order to achieve this goal, stable ceramic inks must be developed. These inks should satisfy specific rheological conditions that can be illustrated within a parameter space defined by the Reynolds and Weber numbers. Printed drops initially deform on impact with a surface by dynamic dissipative processes, but then spread to an equilibrium shape defined by capillarity. We can identify the processes by which these drops interact to form linear features during printing, but there is a poorer level of understanding as to how 2D and 3D structures form. The stability of 2D sheets of ink appears to be possible over a more limited range of process conditions that is seen with the formation of lines. In most cases, the ink solidifies through evaporation and there is a need to control the drying process to eliminate the "coffee ring" defect. Despite these uncertainties, there have been a large number of reports on the successful use of inkjet printing for the manufacture of small ceramic components from a number of different ceramics. This technique offers good prospects as a future manufacturing technique. This review identifies potential areas for future research to improve our understanding of this manufacturing method.展开更多
Scalable fabrication of high-rate micro-supercapacitors(MSCs)is highly desired for on-chip integration of energy storage components.By virtue of the special self-assembly behavior of 2D materials during drying thin fi...Scalable fabrication of high-rate micro-supercapacitors(MSCs)is highly desired for on-chip integration of energy storage components.By virtue of the special self-assembly behavior of 2D materials during drying thin films of their liquid dispersion,a new inkjet printing technique of passivated graphene micro-flakes is developed to directly print MSCs with 3D networked porous microstructure.The presence of macroscale through-thickness pores provides fast ion transport pathways and improves the rate capability of the devices even with solid-state electrolytes.During multiple-pass printing,the porous microstructure effectively absorbs the successively printed inks,allowing full printing of 3D structured MSCs comprising multiple vertically stacked cycles of current collectors,electrodes,and sold-state electrolytes.The all-solid-state heterogeneous 3D MSCs exhibit excellent vertical scalability and high areal energy density and power density,evidently outperforming the MSCs fabricated through general printing techniques.展开更多
Augmented reality(AR)and virtual reality(VR)are two novel display technologies that are under updates.The essential feature of AR/VR is the full-color display that requires high pixel densities.To generate three-color...Augmented reality(AR)and virtual reality(VR)are two novel display technologies that are under updates.The essential feature of AR/VR is the full-color display that requires high pixel densities.To generate three-color pixels,the fluorescent color conversion layer inevitably includes green and red pixels.To fabricate such sort of display kits,inkjet printing is a promising way to position the color conversion layers.In this review article,the progress of AR/VR technologies is first reviewed,and in succession,the state of the art of inkjet printing,as well as two key issues-the optimization of ink and the reduction of coffee-ring effects,are introduced.Finally,some potential problems associated with the color converting layer are highlighted.展开更多
Controlled growth of patterned single-walled carbon nanotubes (SWNTs) is an important issue in many applications. Herein, we demonstrated a method to pattern catalyst via inkjet printing for the growth of SWNTs, using...Controlled growth of patterned single-walled carbon nanotubes (SWNTs) is an important issue in many applications. Herein, we demonstrated a method to pattern catalyst via inkjet printing for the growth of SWNTs, using metal salt solutions as the inks and an ordinary office-use printer. We printed water solutions of cobalt acetate on hydrophilic Si substrates and grew high quality SWNT films. The composition of the precursor solutions and the hydrophilicity of the substrates were crucial factors to the patterning.展开更多
3D bioprinting has the capability to create 3D cellular constructs with the desired shape using a layer-by-layer approach.Inkjet 3D bioprinting,as a key component of 3D bioprinting,relies on the deposition of cell-lad...3D bioprinting has the capability to create 3D cellular constructs with the desired shape using a layer-by-layer approach.Inkjet 3D bioprinting,as a key component of 3D bioprinting,relies on the deposition of cell-laden droplets to create native-like tissues/organs which are envisioned to be transplantable into human body for replacing damaged ones.Benefiting from its superiorities such as high printing resolution and deposition accuracy,inkjet 3D bioprinting has been widely applied to various areas,including,but not limited to,tissue engineering and drug screening in pharmaceutics.Even though inkjet 3D bioprinting has proved its feasibility and versatility in various fields,the current applications of inkjet 3D bioprinting are still limited by the printing technique and material selection.This review,which specifically focuses on inkjet 3D bioprinting,firstly summarizes the techniques,materials,and applications of inkjet 3D bioprinting in tissue engineering and drug screening,subsequently discusses the major challenges that inkjet 3D bioprinting is facing,and lastly summarizes potential solutions to those challenges.展开更多
The major challenge in printable electronics fabrication is to effectively and accurately control a drop-on-demand(Do D) inkjet printhead for high printing quality. In this work, an optimal prediction model, construct...The major challenge in printable electronics fabrication is to effectively and accurately control a drop-on-demand(Do D) inkjet printhead for high printing quality. In this work, an optimal prediction model, constructed with the lumped element modeling(LEM) and the artificial bee colony(ABC) algorithm, was proposed to efficiently predict the combination of waveform parameters for obtaining the desired droplet properties. For acquiring higher simulation accuracy, a modified dynamic lumped element model(DLEM) was proposed with time-varying equivalent circuits, which can characterize the nonlinear behaviors of piezoelectric printhead. The proposed method was then applied to investigate the influences of various waveform parameters on droplet volume and velocity of nano-silver ink, and to predict the printing quality using nano-silver ink. Experimental results show that, compared with two-dimension manual search, the proposed optimal prediction model perform efficiently and accurately in searching the appropriate combination of waveform parameters for printable electronics fabrication.展开更多
IrO2-TiO2 thin films were prepared by atomic layer deposition using Ir（EtCp）（COD） and titanium isopropoxide （TTIP）. The resistivity of IrO2-TiO2 thin films can be easily controlled from 1 500 to 356.7 μΩ·...IrO2-TiO2 thin films were prepared by atomic layer deposition using Ir（EtCp）（COD） and titanium isopropoxide （TTIP）. The resistivity of IrO2-TiO2 thin films can be easily controlled from 1 500 to 356.7 μΩ·cm by the IrO2 intermixing ratio from 0.55 to 0.78 in the IrO2-TiO2 thin films. The low temperature coefficient of resistance（TCR） values can be obtained by adopting IrO2-TiO2 composite thin films. Moreover, the change in the resistivity of IrO2-TiO2 thin films was below 10% even after O2 annealing process at 600 ℃. The step stress test results show that IrO2-TiO2 films have better characteristics than conventional TaN08 heater resistor. Therefore, IrO2-TiO2 composite thin films can be used as a heater resistor material in thermal inkjet printhead.展开更多
3D printing has made remarkable progress in soft tissue reconstruction enabling the custom design of complex material implants with patient specific geometry.The aim of this study was to inkjet print mechanically rein...3D printing has made remarkable progress in soft tissue reconstruction enabling the custom design of complex material implants with patient specific geometry.The aim of this study was to inkjet print mechanically reinforced biocompatible hydrogels.Here,we developed a double crosslinked ink by optimizing the rheological properties of solutions of sodium alginate(NaAlg),NaAlg/transglutaminase(TG),CaCl_(2)and gelatin/CaCl_(2).The results showed that a two-component ink system comprising NaAlg(4%w/v)/TG(0.8%w/v)and gelatin(4%w/v)/CaCl_(2)(3%w/v)gave optimum printability.The mechanical and biological properties of printed alginate/gelatin hydrogels prepared from inks with different gelatin contents,and incorporated fibroblasts,were characterized by Scanning Electron Microscope(SEM),mechanical testing and laser confocal microscopy.The compressive moduli of alginate/gelatin hydrogels could be adjusted from 19.2 kPa±1.2 kPa to 65.9 kPa±3.3 kPa by increasing the content of gelatin.After incubation for 7 d,fibroblasts had permeated all printed hydrogels and the rate of proliferation increased with increasing gelatin content.The highest cell proliferation rate(497%)was obtained in a hydrogel containing 4.5%(w/v)gelatin.This study offers a new strategy for the fabrication of 3D structures used to mimic the function of native tissues.展开更多
The droplet formation dynamics of a Newtonian liquid in a drop-on-demand (DOD) inkjet process is numerically investigated by using a volume-of-fluid (VOF) method. We focus on the nozzle geometry, wettability of the in...The droplet formation dynamics of a Newtonian liquid in a drop-on-demand (DOD) inkjet process is numerically investigated by using a volume-of-fluid (VOF) method. We focus on the nozzle geometry, wettability of the interior surface, and the fluid properties to achieve the stable droplet formation with higher velocity. It is found that a nozzle with contracting angle of 45° generates the most stable and fastest single droplet, which is beneficial for the enhanced printing quality and high-throughput printing rate. For this nozzle with the optimal geometry, we systematically change the wettability of the interior surface, i.e., different contact angles. As the contact angle increases, pinch-off time increases and the droplet speed reduces. Finally, fluids with different properties are investigated to identify the printability range.展开更多
In recent years,the power conversion efficiency of organic solar cells(OSCs)and perovskite(PVSCs)has increased to over 19%and25%,respectively.Meanwhile,the long-term stability of OSCs and PVSCs was also significantly ...In recent years,the power conversion efficiency of organic solar cells(OSCs)and perovskite(PVSCs)has increased to over 19%and25%,respectively.Meanwhile,the long-term stability of OSCs and PVSCs was also significantly improved with a better understanding of the degradation mechanism and the improvement of materials,morphology,and interface stability.As both the efficiency and lifetime of solar cells are approaching the commercialization limit,fabrication methods for large-area OSCs and PVSCs that can be directly transferred from lab to fab become essential to promote the industrialization of OSCs and PVSCs.Compared with the coating methods,inkjet printing is a mature industrial technology with the advantages of random digital patterning,excellent precision and fast printing speed,which is considered to have great potential in solar cell fabrication.Many efforts have been devoted to developing inkjet-printed OSCs and PVSCs,and much progress has been achieved in the last few years.In this review,we first introduced the working principle of inkjet printing,the rheology requirements of inks,and the behaviors of the droplets.We then summarized the recent research progresses of the inkjet-printed OSCs and PVSCs to facilitate knowledge transfer between the two technologies.In the end,we gave a perspective on inkjet-printed OSCs and PVSCs.展开更多
In this study the effects of the actuation waveforms on the droplet generation in a drop-on-demand inkjet printing are studied systematically by numerical simulations.Two different types of waveforms,namely the unipol...In this study the effects of the actuation waveforms on the droplet generation in a drop-on-demand inkjet printing are studied systematically by numerical simulations.Two different types of waveforms,namely the unipolar and bipolar actuations,are investigated for three fluids with different physical properties.We focus on two key parameters,which are the dwell time and the velocity amplitude.For the unipolar driving,the ejection velocity and the ejected liquid volume are both increased as the velocity amplitude becomes larger.The dwell time only has minor effects on both the ejection velocity and the ejected liquid volume.The ejection velocity decreases significantly for large liquid viscosity,while the influences of viscosity on the ejected liquid volume are much weaker.Four different droplet morphologies and the corresponding parameter ranges are identified.The droplet radius can be successfully reduced to about 40%e of the nozzle exit radius.For the bipolar waveforms,same droplet morphologies are observed but with shifted boundaries in the phase space.The minimal radius of stable droplet produced by the bipolar waveforms is even smaller compared to the unipolar ones.展开更多
In this work, a simple procedure for the preparation of an inkjet printed disposable graphene electrode is reported. Commercial graphene ink was printed on a kapton substrate and the resulting electrode was 30 min tre...In this work, a simple procedure for the preparation of an inkjet printed disposable graphene electrode is reported. Commercial graphene ink was printed on a kapton substrate and the resulting electrode was 30 min treated by oxygen plasma, then modified by a bismuth salt. The as prepared electrode was characterized by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), laser scanning microscopy (LSM) and scanning electron microscopy (SEM) coupled to energy-dispersive X-ray spectroscopy (EDX). The sensing properties of the characterized electrodes were then investigated using cyclic voltammetry and Electrochemical Impedance Spectroscopy (EIS). Afterwards, these electrodes were exploited in a comparative way for the electroanalysis of Cadmium(II) and Lead(II) ions. An increase in the electrode sensitivity due to its modification and to the presence of bismuth was observed. Some preliminary experiments based on stripping square wave voltammetry highlighted the interest of using the proposed disposable inkjet printed electrodes for the electrochemical detection of heavy metals in tap water.展开更多
It is a big challenge to construct large-scale,high-resolution and high-performance inkjet-printed metal oxide thin film transistor(TFT)arrays with independent gates for the new printed displays.Here,a self-confined i...It is a big challenge to construct large-scale,high-resolution and high-performance inkjet-printed metal oxide thin film transistor(TFT)arrays with independent gates for the new printed displays.Here,a self-confined inkjet printing technology has been developed to construct large-area(64×64 array),high-resolution and high-performance metal oxide bilayer(In_(2)O_(3)/IGZO)heterojunction TFTs with independent bottom gates on transparent glass substrates.Inkjet printing In_(2)O_(3) dot arrays with the diameters from 55 to 70μm and the thickness of~10 nm were firstly deposited on UV/ozone treated AlO_(x) dielectric layers,and then IGZO dots were selectively printed on the top of In_(2)O_(3) dots by self-confined technology to form In_(2)O_(3)/IGZO heterojunction channels.When the inkjet-printed IO layers treated by UV/ozone for more than 30 min or oxygen plasma for 5 min prior to print IGZO thin films,the mobility of the resulting printed In_(2)O_(3)/IGZO heterojunction TFTs are correspondingly enhanced to be 18.80 and 28.44 cm^(2) V^(-1) s^(-1) with excellent on/off ratios(>10^(8))and negligible hysteresis.Furthermore,the printed N-Metal-Oxide-Semiconductor(NMOS)inverter consisted of an In_(2)O_(3)/IGZO TFT and an IGZO TFT has been demonstrated,which show excellent performance with the voltage gain up to 112.The strategy demonstrated here can be considered as general approaches to realize a new generation of high-performance printed logic gates,circuits and display driving circuits.展开更多
基金supported by the National Natural Science Foundation of China(No.62374142)Fundamental Research Funds for the Central Universities(Nos.20720220085 and 20720240064)+2 种基金External Cooperation Program of Fujian(No.2022I0004)Major Science and Technology Project of Xiamen in China(No.3502Z20191015)Xiamen Natural Science Foundation Youth Project(No.3502Z202471002)。
文摘Super-fine electrohydrodynamic inkjet(SIJ)printing of perovskite nanocrystal(PNC)colloid ink exhibits significant potential in the fabrication of high-resolution color conversion microstructures arrays for fullcolor micro-LED displays.However,the impact of solvent on both the printing process and the morphology of SIJ-printed PNC color conversion microstructures remains underexplored.In this study,we prepared samples of CsPbBr3PNC colloid inks in various solvents and investigated the solvent's impact on SIJ printed PNC microstructures.Our findings reveal that the boiling point of the solvent is crucial to the SIJ printing process of PNC colloid inks.Only does the boiling point of the solvent fall in the optimal range,the regular positioned,micron-scaled,conical PNC microstructures can be successfully printed.Below this optimal range,the ink is unable to be ejected from the nozzle;while above this range,irregular positioned microstructures with nanoscale height and coffee-ring-like morphology are produced.Based on these observations,high-resolution color conversion PNC microstructures were effectively prepared using SIJ printing of PNC colloid ink dispersed in dimethylbenzene solvent.
基金supported by the Tsinghua University–Toyota Research Center Project。
文摘As an accurate 2D/3D fabrication tool,inkjet printing technology has great potential in preparation of micro electronic devices.The morphology of droplets produced by the inkjet printer has a great impact on the accuracy of deposition.In this study,the drop-on-demand(DoD)inkjet simulation model was established,and the accuracy of the simulation model was verified by corresponding experiments.The simulation result shows that the velocity of the droplet front and tail,as well as the time to disconnect from the nozzle is mainly affected by density(ρ),viscosity(μ)and surface tension(σ)of droplets.When the liquid filament is about to disconnect from the nozzle,the filament length and filament front velocity are found to have a linear correlation withσ/ρμand ln(ρ/(μσ1/2)).
基金financially supported by the National Natural Science Foundation of China(No.51873212)the CAS-Croucher Funding Scheme for Joint Laboratories:Poly U-CIAC Joint Laboratory(No.121522KYSB20200040)。
文摘Inkjet printing has emerged as a potential solution processing method for large-area patterned films.During inkjet printing,a single droplet without satellite droplet is required for high-quality film.Herein,we propose a strategy for obtaining a single droplet by adjusting the reduced concentration(c/c^(*),where c^(*)is the critical overlap concentration)in the range of 1.0-1.5.Droplet formation can be categorized into three distinct regimes:(1)c/c^(*)<1.0,satellite droplet;(2)c/c^(*)=1.0-1.5,single droplet;(3)c/c^(*)>2.0,no droplet.Furthermore,an inertial-capillary balance led to the 2/3-power scaling of the minimum radius with time for the solutions of c/c^(*)<1.0.However,for the solutions of c/c^(*)=1.0-1.5,the ligament radius decreased exponentially with time.Moreover,the Weissenberg number was higher than the critical value of 0.5,indicating that the polymer chains underwent coil-stretch transition.The viscoelastic-capillary balance dominated instead of the inertial-capillary balance.The resulting viscoelastic resistance reduced the length of the ligament and increased the velocity difference between the satellite and main droplets.Consequently,a single droplet was formed.In addition,the law can be successfully generalized to various molecular weights,molecular structures and solvents.
基金supported by the National Key Researchand Development Programof China(No.2022YFB4600101)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB 0470303)+2 种基金the National Natural Science Foundation of China(No.21974057)the Western Light Project of Chinese Academy of Sciences(No.xbzg-zdsy-202007)the Oasis Scholar of Shihezi University and the Central Government to Guide Local Technological Development(No.23ZYQA315).
文摘Inkjet 3D printing has potential in the additive manufacturing of electronic circuits and devices.However,inks that can be used for printing layers with T5%>300℃ or hardness>200 MPa have been rarely reported.Cyanate ester(CE)polymers have excellent thermal stability,high strength,and low shrinkage compared to other common dielectric inks for inkjet 3D printing,but cannot be quickly shaped by ultraviolet(UV)irradiation or thermal treatment.Combining CEs with UV-curable monomers may be a possible way to accelerate crosslinking,but there are challenges from the adverse effects of the dilution of both monomers.In this study,dielectric inks with acrylate and cyanate moieties were developed.The low viscosity and surface tension of the CE precursor(Bisphenol E cyanate ester)were combined with photocurable acrylate diluent monomers and cross-linker to realize an ink suitable for inkjet 3D printing.An internal dual three-dimensional cross-linked network structure resin was prepared by a combination of photocuring and thermal curing with T5%up to 326.69℃,hardness up to 431.84 MPa,dielectric constant of 2.70 at 8 GHz,and shrinkage of 1.64%.The developed dielectric inks can be applied to the 3D printing of printed circuit boards and other electronic devices that require dielectric properties.
基金funding from the Natural Science Foundation of Jiangsu Province(BK20210480)the grant from National Innovation Center of Advanced Dyeing&Finishing Technology(2022GCJJ08).
文摘Zn anode-based electrochromic devices(ZECDs)stand out as a highly promising technology in the upcoming era of multifunctional electronic devices,offering a blend of electrochromic capabilities and energy storage functions within a single transparent platform.However,significant challenges persist in achieving efficient patterning,ensuring long-term stability,and fast color-switching kinetics for these devices.In this study,heterogeneous tungsten oxide nanowires(W_(17)O_(47)/Na_(0.1)WO_(3),WNOs)are formulated into inkjet printing ink to assemble patternable ZECDs.The heterogeneous electrode structure of WNO enables a highly capacitive-controlled mechanism that promotes fast electrochromic/electrochemical behavior.Notably,by utilizing a three-dimensional MXene mesh modified substrate,the inkjet-printed ZECDs exhibit a wide optical modulation range of 69.13%,rapid color-changing kinetics(t_(c)=4.1 s,t_(b)=5.4 s),and highly reversible capacities of 70 mAh cm^(-2)over 1000 cycles.This scalable strategy develops the patterned electrodes with a wide optical modulation range and substantial energy storage properties,offering promising prospects for their application in next-generation smart electronics.
基金financially supported by the National Natural Science Foundation of China (Nos. 21574130, 51473161, 51873212)the Ministry of Science and Technology of China (No. 2015CB655001)National Key R&D Program of "Strategic Advanced Electronic Materials" (Nos. 2016YFB0401301, 2016YFB04011001)
文摘Polymer thin film with uniform thickness and flat surface profile is the key point for polymer light emitting diodes(PLEDs) by inkjet printing. However, the coffee ring effect is usually observed due to the mismatch between the evaporation of the solvent and the decrease of solution volume, which promotes the formation of radial flow from the interior of the drop to the edge. In this paper, coffee ring effects of inkjet printed poly(spirobifluorene) films were proposed to be restrained by decreasing capillary force by adding co-solvent with high boiling point and high viscosity to the main solvent. The low evaporation rate of the co-solvent can reduce the driving force of the radial flow; meanwhile the high viscosity of the co-solvent can increase the resistance of the radial flow. Thus, polymer films with improve uniformity can be obtained due to the suppression of the radial flow. The device performance was greatly improved under the condition of proper film thickness and film uniformity and the maximum luminous efficiency of devices with inkjet printed poly(spirobifluorene) can reach 80% of the spin-coated devices.
基金supported by National Natural Science Foundation of China(Grant Nos.11274308 and 21401202)
文摘By means of inkjet printing technique, flexible and all-solid-state micro-supercapacitors(MSCs) were fabricated with carbon-based hybrid ink composed of graphene oxide(GO,98.0vol.%) ink and commercial pen ink(2.0vol.%). A small amount of commercial pen ink was added to effectively reduce the agglomeration of theGO sheets during solvent evaporation and the following reduction processes in which the presence of graphite carbon nanoparticles served as nano-spacer to separate GO sheets. The printed device fabricated using the hybrid ink,combined with the binder-free microelectrodes and interdigital microelectrode configuration, exhibits nearly 780%enhancement in areal capacitance compared with that of pure GO ink. It also shows excellent flexibility and cycling stability with nearly 100% retention of the areal capacitance after 10,000 cycles. The all-solid-state device can be optionally connected in series or in parallel to meet the voltage and capacity requirements for a given application.This work demonstrates a promising future of the carbonbased hybrid ink for directly large-scale inkjet printing MSCs for disposable energy storage devices.
文摘In order to build a ceramic component by inkjet printing, the object must be fabricated through the interaction and solidification of drops, typically in the range of 10–100 p L. In order to achieve this goal, stable ceramic inks must be developed. These inks should satisfy specific rheological conditions that can be illustrated within a parameter space defined by the Reynolds and Weber numbers. Printed drops initially deform on impact with a surface by dynamic dissipative processes, but then spread to an equilibrium shape defined by capillarity. We can identify the processes by which these drops interact to form linear features during printing, but there is a poorer level of understanding as to how 2D and 3D structures form. The stability of 2D sheets of ink appears to be possible over a more limited range of process conditions that is seen with the formation of lines. In most cases, the ink solidifies through evaporation and there is a need to control the drying process to eliminate the "coffee ring" defect. Despite these uncertainties, there have been a large number of reports on the successful use of inkjet printing for the manufacture of small ceramic components from a number of different ceramics. This technique offers good prospects as a future manufacturing technique. This review identifies potential areas for future research to improve our understanding of this manufacturing method.
基金financial support of the Swedish Research Council through the Marie Sklodowska-Curie International Career Grant (No.2015-00395,co-funded by Marie Sklodowska-Curie Actions, through the Project INCA 600398)the Formas Foundation through the Future Research Leaders Grant (No.2016-00496)+3 种基金the AForsk Foundation (Grant No.17-352)the Olle Engkvist Byggmastare Foundation (Grant No.2014/799)the Academy of Finland (Grant No.288945 and 319408)Academy of Finland Research Infrastructure "Printed Intelligence Infrastructure" (PII-FIRI,Grant No. 320019)
文摘Scalable fabrication of high-rate micro-supercapacitors(MSCs)is highly desired for on-chip integration of energy storage components.By virtue of the special self-assembly behavior of 2D materials during drying thin films of their liquid dispersion,a new inkjet printing technique of passivated graphene micro-flakes is developed to directly print MSCs with 3D networked porous microstructure.The presence of macroscale through-thickness pores provides fast ion transport pathways and improves the rate capability of the devices even with solid-state electrolytes.During multiple-pass printing,the porous microstructure effectively absorbs the successively printed inks,allowing full printing of 3D structured MSCs comprising multiple vertically stacked cycles of current collectors,electrodes,and sold-state electrolytes.The all-solid-state heterogeneous 3D MSCs exhibit excellent vertical scalability and high areal energy density and power density,evidently outperforming the MSCs fabricated through general printing techniques.
基金supported by the National Natural Science Foundation of China (11904302)the Fundamental Research Funds for the Central Universities (Grant No.20720190005)+1 种基金the Major Science and Technology Project of Xiamen in China (3502Z20191015)Hong Kong University of Science and Technology-Foshan Joint Research Program (FSUST19-FYTRI11)
文摘Augmented reality(AR)and virtual reality(VR)are two novel display technologies that are under updates.The essential feature of AR/VR is the full-color display that requires high pixel densities.To generate three-color pixels,the fluorescent color conversion layer inevitably includes green and red pixels.To fabricate such sort of display kits,inkjet printing is a promising way to position the color conversion layers.In this review article,the progress of AR/VR technologies is first reviewed,and in succession,the state of the art of inkjet printing,as well as two key issues-the optimization of ink and the reduction of coffee-ring effects,are introduced.Finally,some potential problems associated with the color converting layer are highlighted.
基金financially supported by Ministry of Science and Technology of the People's Republic of China(No. 2016YFA0201904)the National Natural Science Foundation of China (Nos. 21631002, U1632119 and 91333105)
文摘Controlled growth of patterned single-walled carbon nanotubes (SWNTs) is an important issue in many applications. Herein, we demonstrated a method to pattern catalyst via inkjet printing for the growth of SWNTs, using metal salt solutions as the inks and an ordinary office-use printer. We printed water solutions of cobalt acetate on hydrophilic Si substrates and grew high quality SWNT films. The composition of the precursor solutions and the hydrophilicity of the substrates were crucial factors to the patterning.
基金supported by the Starry Night Science Fund of Zhejiang University Shanghai Institute for Advanced Study(No.SN-ZJU-SIAS-004)the National Natural Science Foundation of China(No.52075482)。
文摘3D bioprinting has the capability to create 3D cellular constructs with the desired shape using a layer-by-layer approach.Inkjet 3D bioprinting,as a key component of 3D bioprinting,relies on the deposition of cell-laden droplets to create native-like tissues/organs which are envisioned to be transplantable into human body for replacing damaged ones.Benefiting from its superiorities such as high printing resolution and deposition accuracy,inkjet 3D bioprinting has been widely applied to various areas,including,but not limited to,tissue engineering and drug screening in pharmaceutics.Even though inkjet 3D bioprinting has proved its feasibility and versatility in various fields,the current applications of inkjet 3D bioprinting are still limited by the printing technique and material selection.This review,which specifically focuses on inkjet 3D bioprinting,firstly summarizes the techniques,materials,and applications of inkjet 3D bioprinting in tissue engineering and drug screening,subsequently discusses the major challenges that inkjet 3D bioprinting is facing,and lastly summarizes potential solutions to those challenges.
基金Projects(2014AA052101-3,2014AA052102)supported by the National High Technology Research and Development Program of ChinaProjects(51205389,61105067)supported by the National Natural Science Foundation of China
文摘The major challenge in printable electronics fabrication is to effectively and accurately control a drop-on-demand(Do D) inkjet printhead for high printing quality. In this work, an optimal prediction model, constructed with the lumped element modeling(LEM) and the artificial bee colony(ABC) algorithm, was proposed to efficiently predict the combination of waveform parameters for obtaining the desired droplet properties. For acquiring higher simulation accuracy, a modified dynamic lumped element model(DLEM) was proposed with time-varying equivalent circuits, which can characterize the nonlinear behaviors of piezoelectric printhead. The proposed method was then applied to investigate the influences of various waveform parameters on droplet volume and velocity of nano-silver ink, and to predict the printing quality using nano-silver ink. Experimental results show that, compared with two-dimension manual search, the proposed optimal prediction model perform efficiently and accurately in searching the appropriate combination of waveform parameters for printable electronics fabrication.
基金supported by a grant from the Fundamental R&D Program for Core Technology of Materials funded by the Ministry of Knowledge Economy, Republic of Koreasupported by Basic Science Research program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2010-0001-226)
文摘IrO2-TiO2 thin films were prepared by atomic layer deposition using Ir（EtCp）（COD） and titanium isopropoxide （TTIP）. The resistivity of IrO2-TiO2 thin films can be easily controlled from 1 500 to 356.7 μΩ·cm by the IrO2 intermixing ratio from 0.55 to 0.78 in the IrO2-TiO2 thin films. The low temperature coefficient of resistance（TCR） values can be obtained by adopting IrO2-TiO2 composite thin films. Moreover, the change in the resistivity of IrO2-TiO2 thin films was below 10% even after O2 annealing process at 600 ℃. The step stress test results show that IrO2-TiO2 films have better characteristics than conventional TaN08 heater resistor. Therefore, IrO2-TiO2 composite thin films can be used as a heater resistor material in thermal inkjet printhead.
基金This work was supported by the Development Projects of Key Research(No.2018YFE0207900)People’s Liberation Army(No.BWS17J036,18-163-13-ZT-003-011-01)the National Natural Science Foundation of China(Nos.51835010 and 51375371).
文摘3D printing has made remarkable progress in soft tissue reconstruction enabling the custom design of complex material implants with patient specific geometry.The aim of this study was to inkjet print mechanically reinforced biocompatible hydrogels.Here,we developed a double crosslinked ink by optimizing the rheological properties of solutions of sodium alginate(NaAlg),NaAlg/transglutaminase(TG),CaCl_(2)and gelatin/CaCl_(2).The results showed that a two-component ink system comprising NaAlg(4%w/v)/TG(0.8%w/v)and gelatin(4%w/v)/CaCl_(2)(3%w/v)gave optimum printability.The mechanical and biological properties of printed alginate/gelatin hydrogels prepared from inks with different gelatin contents,and incorporated fibroblasts,were characterized by Scanning Electron Microscope(SEM),mechanical testing and laser confocal microscopy.The compressive moduli of alginate/gelatin hydrogels could be adjusted from 19.2 kPa±1.2 kPa to 65.9 kPa±3.3 kPa by increasing the content of gelatin.After incubation for 7 d,fibroblasts had permeated all printed hydrogels and the rate of proliferation increased with increasing gelatin content.The highest cell proliferation rate(497%)was obtained in a hydrogel containing 4.5%(w/v)gelatin.This study offers a new strategy for the fabrication of 3D structures used to mimic the function of native tissues.
基金Project supported by the National Natural Science Foundation of China(No.11802004)
文摘The droplet formation dynamics of a Newtonian liquid in a drop-on-demand (DOD) inkjet process is numerically investigated by using a volume-of-fluid (VOF) method. We focus on the nozzle geometry, wettability of the interior surface, and the fluid properties to achieve the stable droplet formation with higher velocity. It is found that a nozzle with contracting angle of 45° generates the most stable and fastest single droplet, which is beneficial for the enhanced printing quality and high-throughput printing rate. For this nozzle with the optimal geometry, we systematically change the wettability of the interior surface, i.e., different contact angles. As the contact angle increases, pinch-off time increases and the droplet speed reduces. Finally, fluids with different properties are investigated to identify the printability range.
基金financially supported by the Youth Innovation Promotion Association,CAS(No.2019317)CAS-CSIRO joint project(No.121E32KYSB20190021)of the Chinese Academy of Sciences。
文摘In recent years,the power conversion efficiency of organic solar cells(OSCs)and perovskite(PVSCs)has increased to over 19%and25%,respectively.Meanwhile,the long-term stability of OSCs and PVSCs was also significantly improved with a better understanding of the degradation mechanism and the improvement of materials,morphology,and interface stability.As both the efficiency and lifetime of solar cells are approaching the commercialization limit,fabrication methods for large-area OSCs and PVSCs that can be directly transferred from lab to fab become essential to promote the industrialization of OSCs and PVSCs.Compared with the coating methods,inkjet printing is a mature industrial technology with the advantages of random digital patterning,excellent precision and fast printing speed,which is considered to have great potential in solar cell fabrication.Many efforts have been devoted to developing inkjet-printed OSCs and PVSCs,and much progress has been achieved in the last few years.In this review,we first introduced the working principle of inkjet printing,the rheology requirements of inks,and the behaviors of the droplets.We then summarized the recent research progresses of the inkjet-printed OSCs and PVSCs to facilitate knowledge transfer between the two technologies.In the end,we gave a perspective on inkjet-printed OSCs and PVSCs.
基金National Natural Science Foundation of China(Grants 91848201,11988102,11521202,11872004.11802004)The authors also acknowledge the partial support from the Beijing Natural Science Foundation(Grants L172002)+1 种基金A.B.Aqecl would like to thank the Chinese Scholarship Council(CSC)for providing Chinese Government Scholarship(CGs)The numericalsimulations were performed on the National Super Computing Centerin Tianjin.China.
文摘In this study the effects of the actuation waveforms on the droplet generation in a drop-on-demand inkjet printing are studied systematically by numerical simulations.Two different types of waveforms,namely the unipolar and bipolar actuations,are investigated for three fluids with different physical properties.We focus on two key parameters,which are the dwell time and the velocity amplitude.For the unipolar driving,the ejection velocity and the ejected liquid volume are both increased as the velocity amplitude becomes larger.The dwell time only has minor effects on both the ejection velocity and the ejected liquid volume.The ejection velocity decreases significantly for large liquid viscosity,while the influences of viscosity on the ejected liquid volume are much weaker.Four different droplet morphologies and the corresponding parameter ranges are identified.The droplet radius can be successfully reduced to about 40%e of the nozzle exit radius.For the bipolar waveforms,same droplet morphologies are observed but with shifted boundaries in the phase space.The minimal radius of stable droplet produced by the bipolar waveforms is even smaller compared to the unipolar ones.
文摘In this work, a simple procedure for the preparation of an inkjet printed disposable graphene electrode is reported. Commercial graphene ink was printed on a kapton substrate and the resulting electrode was 30 min treated by oxygen plasma, then modified by a bismuth salt. The as prepared electrode was characterized by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), laser scanning microscopy (LSM) and scanning electron microscopy (SEM) coupled to energy-dispersive X-ray spectroscopy (EDX). The sensing properties of the characterized electrodes were then investigated using cyclic voltammetry and Electrochemical Impedance Spectroscopy (EIS). Afterwards, these electrodes were exploited in a comparative way for the electroanalysis of Cadmium(II) and Lead(II) ions. An increase in the electrode sensitivity due to its modification and to the presence of bismuth was observed. Some preliminary experiments based on stripping square wave voltammetry highlighted the interest of using the proposed disposable inkjet printed electrodes for the electrochemical detection of heavy metals in tap water.
基金This work was financially supported by the National Key R&D Program of“Strategic Advanced Electronic Materials”(No.2016YFB04011100)the Basic Research Program of Jiangsu Province(Nos.BK20161263,SBK2017041510)+3 种基金the Science and Technology Program of Guangdong Province(Nos.2016B090906002,2019B010924002)the Basic Research Program of Suzhou Institute of Nanotech and Nano-bionics(No.Y5AAY21001)the National Natural Science Foundation of China(Nos.61750110517,61805166)the Cooperation Project of Vacuum Interconnect Nano X Research Facility(NANO-X)of Suzhou Nanotechnology and Nano-Bionics Institute(H060)。
文摘It is a big challenge to construct large-scale,high-resolution and high-performance inkjet-printed metal oxide thin film transistor(TFT)arrays with independent gates for the new printed displays.Here,a self-confined inkjet printing technology has been developed to construct large-area(64×64 array),high-resolution and high-performance metal oxide bilayer(In_(2)O_(3)/IGZO)heterojunction TFTs with independent bottom gates on transparent glass substrates.Inkjet printing In_(2)O_(3) dot arrays with the diameters from 55 to 70μm and the thickness of~10 nm were firstly deposited on UV/ozone treated AlO_(x) dielectric layers,and then IGZO dots were selectively printed on the top of In_(2)O_(3) dots by self-confined technology to form In_(2)O_(3)/IGZO heterojunction channels.When the inkjet-printed IO layers treated by UV/ozone for more than 30 min or oxygen plasma for 5 min prior to print IGZO thin films,the mobility of the resulting printed In_(2)O_(3)/IGZO heterojunction TFTs are correspondingly enhanced to be 18.80 and 28.44 cm^(2) V^(-1) s^(-1) with excellent on/off ratios(>10^(8))and negligible hysteresis.Furthermore,the printed N-Metal-Oxide-Semiconductor(NMOS)inverter consisted of an In_(2)O_(3)/IGZO TFT and an IGZO TFT has been demonstrated,which show excellent performance with the voltage gain up to 112.The strategy demonstrated here can be considered as general approaches to realize a new generation of high-performance printed logic gates,circuits and display driving circuits.
