- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Giant Dielectric Constant and Tunable Phase-Transition Characteristics of ZnF <sub/>2</sub> /BaF <sub/>2</sub> -Modified BaTiO <sub/>3</sub> Thick Films
摘要： High performance capacitors have been investigated to meet higher integration density with optimized charge-storing capability. Here we introduce nonconventional thick film dielectric compositions based on 95BaTiO3-xZnF2-(2-x)BaF2-3glass (x=0.5, 1.0 and 1.5) where the relative content of ZnF2/BaF2 is critical in controlling dielectric behavior. The thick films were prepared on Cu foils by regular screen-printing and then firing at 950oC in inert atmosphere. As an optimal example, thick film composition modified with 1.0ZnF2/1.0BaF2 exhibited a dielectric constant of ~1,903 and a dielectric loss of ~0.04 at 1 MHz with dispersive dielectric relaxation behavior, which are far better than any reported corresponding values so far. Particularly, it was very interesting to observe that Curie Temperature was tunable from -19 oC to +34 oC, depending on the relative content of fluoride additives only within the 2 mol% range. Dependency of the relative contents of the fluorides is primarily investigated in regard to microstructure and dielectric properties.
关键词： dielectric materials/properties,printing,titanates
更新于2025-09-23 15:21:01
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[IEEE 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Honolulu, HI, USA (2018.7.18-2018.7.21)] 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) - Inkjet Printed Parallel Plate Capacitors Using PVP Polymer Dielectric Ink on Flexible Polyimide Substrates
摘要： Inkjet printing (IJP) is an exciting new additive manufacturing technology that promises monolithic electronic circuit fabrication of μm thin low-cost large-area electronic low-cost body-worn flexible sensors. In this work, we demonstrate inkjet printed multilayer metal-dielectric-metal capacitors on flexible polyimide (PI) substrate by formulating a custom dielectric ink based on Poly 4-vinylphenol (PVP). Silver nanoparticle ink was used for printing the conductive parallel metal plates. We also demonstrate control over the capacitance values by varying the design parameters and succeeded in printing capacitors in the range 8.8 pF to 467 pF, with excellent repeatability on flexible PI substrates. A functional LC circuit using these printed capacitors has been designed and demonstrated to have a resonance frequency of 24.3 MHz. These results are a vital step forward towards monolithic printing of flexible electronic circuits using IJP technique for many applications such as body-worn sensors.
关键词： Inkjet printing,PVP dielectric ink,flexible electronics,polyimide substrate,capacitors
更新于2025-09-23 15:21:01
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[ASME ASME 2018 Conference on Smart Materials, Adaptive Structures and Intelligent Systems - San Antonio, Texas, USA (Monday 10 September 2018)] Volume 2: Mechanics and Behavior of Active Materials; Structural Health Monitoring; Bioinspired Smart Materials and Systems; Energy Harvesting; Emerging Technologies - Manufacture of Lenses and Diffraction Gratings Using DLP As an Additive Manufacturing Technology
摘要： This document condenses the results obtained when 3D printing lenses and their potential use as diffraction gratings using Digital Light Processing (DLP), as an additive manufacturing technique. This project investigated the feasibility of using DLP additive manufacturing for producing custom designed lenses and gratings. DLP was identified as the preferred manufacturing technology for gratings fabrication. Diffraction gratings take advantage of the anisotropy, in additive manufacturing processes, to produce a collated pattern of multiple fringes on a substrate with completely smooth surfaces. The gratings are transmissive and were manufactured with slit separations of 10, 25 and 50 μm. More than 50 samples were printed at various build angles and mechanically treated for maximum optical transparency. The variables of the irradiance equation were obtained from photographs taken with an optical microscope. These values were used to estimate theoretical irradiance patterns of a diffraction grating and compared against the experimental 3-D printed grating. The resulting patterns were found to be remarkably similar in amplitude and distance between peaks when compared to theoretical values.
关键词： 3D printing,lenses,Digital Light Processing (DLP),additive manufacturing,diffraction gratings
更新于2025-09-23 15:21:01
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Extremely Soft, Conductive, and Transparent Ionic Gels by 3D Optical Printing
摘要： A series of 3D printable multifunctional ionic gels (IGs) are developed incorporating ionic liquid (IL) in the thiol–ene network of thiol-based end-crosslinker and acrylate monomers. The resulted gels, termed as thiol-ionic gels (T-IGs), are highly transparent and very soft with IL content of 70–85 wt%. The mechanical and conductive properties of the T-IGs are found to be largely dependent on the IL content, end-crosslinker functionalities, and chain-length of monomers. Progression of ionic conductivity is observed with an increase in IL content and conductivity as high as 5.40 mS cm?1 is attained for longer acrylate group containing T-IGs at room temperature, while further increase is observed at elevated temperature. T-IGs in all systems are found to exhibit superior thermal stability. Three-dimensional fabrication of these functional T-IGs is achieved by optical 3D printing process with microscale resolution in facile steps.
关键词： multifunctional ionic gels,3D printing,thiol–ene reaction,ionic liquids
更新于2025-09-23 15:21:01
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Lasera??Induced Forward Transfer: A Digital Approach for Printing Devices on Regular Paper
摘要： Inkjet printing (IJP) is the most widespread direct-write technique in paper electronics. However, this technique cannot be used for printing devices on untreated regular paper, since its low-viscosity nanoinks leak through the cellulose fibers. Thus, a planarization coating is frequently used as a barrier, even though this makes substrates more expensive and less eco-friendly. Alternatively, high solid content screen printing (SP) inks could allow printing on regular paper due to their high viscosity and large particle size; however, they cannot be printed through IJP. Another digital technique is then required: laser-induced forward transfer (LIFT). This work aims at proving the feasibility of LIFT for printing devices on regular paper. The main transfer parameters are systematically varied to obtain uniform Ag-SP interconnects, whose performance is improved by a multiple-printing approach. It results in low resistances with much better performance than those typical of IJP. After optimizing the functionality of the printed lines, a proof-of-concept consisting of a radio-frequency inductor is provided. The characterization of the device shows a substantially higher performance than that of the same device printed with IJP ink in similar conditions, which proves the potential of LIFT for digitally fabricating devices on regular paper.
关键词： paper electronics,laser printing,screen printing ink,laser forward transfer,printed electronics
更新于2025-09-23 15:19:57
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Bi-scale interfacial bond behaviors of CCF/PEEK composites by plasma-laser cooperatively assisted 3D printing process
摘要： 3D printed continuous carbon fiber reinforced PEEK (CCF/PEEK) composites have got much attention because of their excellent mechanical, thermal and chemical performance and the formability of complex structural components. However, there are always two different weak-bond interfaces limiting the application of the composites critically, which are the poor interlayer bond and the weak interface between carbon fibers and PEEK. A plasma-laser cooperatively assisted 3D printing process was utilized to improve the bi-scale interface. After optimizing, the interlaminar shear strength can be improved from 5.78MPa to 39.05MPa. After analyzing the failure mode and bi-scale interfacial bond mechanism, it’s found that the laser mainly improves the interlayer bond and crystallinity, while the plasma effectively improves the mechanical modulus by treating the surface of the carbon fibers chemically and physically. The work provides a really novel idea for developing the 3D printed CCF/PEEK composites for further application in aerospace and automotive industries.
关键词： Plasma-laser cooperatively assisted treatment,Bi-scale interface bond,3D printing,Continuous carbon fiber reinforced PEEK
更新于2025-09-23 15:19:57
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Digital printing of efficient dye-sensitized solar cells (DSSCs)
摘要： This study reports on the printing of TiO2 nanoparticles and the sensitization of the photoanode by a new digital printing technology, named Digital Materials Deposition “DMD” to fabricate semi-transparent DSSCs. In this study, the push-pull dye coded “D35” and I3?/I? were used respectively as sensitizer and redox mediator. The photovoltaic performances of the solar cells printed with the DMD technology were compared to those prepared by the conventional method consisting of screen-printed nanoparticles and dying process by overnight soaking of the electrode into a solution of the sensitizer. Scanning Electron Microscopy shows that the DMD printed ?lm is more porous than the one deposited by screen printing. The cells prepared by DMD give higher solar energy conversion e?ciency (Jsc = 12.65 mA/cm2, Voc = 775 mV, FF = 75%, PEC = 7.4%) than with conventional screen-printing technique (Jsc = 10.03 mA/cm2, Voc = 760 mV, FF = 72%, PEC = 5.48%). IMVS/IMPS measurements demonstrate that the superior photocurrent density delivered by DMD printed solar cells is due to a higher charge collection e?ciency. Overall, this study demonstrates that DMD technology simpli?es the DSSC fabrication process with a reduction of the material consumption and it is quick and e?cient representing an innovative and attractive method to manufacture DSSCs.
关键词： Semi-transparent,Fast fabrication process,Dye-sensitized solar cells,Digital printing
更新于2025-09-23 15:19:57
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Surface Engineered Colloidal Quantum Dots Toward Complete Green Process
摘要： The rising demand for eradicating hazardous substances in the workplace has motivated vigorous researches on environmentally-sustainable manufacturing processes of colloidal quantum dots (QDs) for their optoelectronic applications. Despite remarkable achievements witnessed in QD materials (e.g., Pb- or Cd-free QDs), the progress in the eco-friendly process is far falling behind and thus the practical use of QDs. Herein, a complete “green” process of QDs, which excludes environmentally unfriendly elements from QDs, ligands, or solvents, is presented. The implant of mono-2-(methacryloyloxy)ethyl succinate (MMES) ligands renders InP/ZnSexS1-x QDs dispersed in eco-friendly polar solvents that are widely accepted in the industry while keeping photophysical properties of QDs unchanged. The MMES-capped QDs show exceptional colloidal stabilities in a range of green polar solvents that permit uniform inkjet printing of QD dispersion. In addition, MMES-capped QDs are also compatible with commercially available photo-patternable resins, and the cross-linkable moiety within MMES further facilitates the achievement in the formation of well-defined, micrometer-scale patterning of QD optical films. The presented materials, all composed of simple, scalable, and environmentally-safe compounds, promise low environmental impact during the processing of QDs, and thus will catalyze the practicable use of QDs in a variety of optoelectronic devices.
关键词： photo-patterning,electroluminescence devices,environmentally friendly processing,inkjet printing,quantum dots
更新于2025-09-23 15:19:57
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Lasera??Printed, Flexible Graphene Pressure Sensors
摘要： While the outstanding properties of graphene have attracted a lot of attention, one of the major bottlenecks of its widespread usage is its availability in large volumes. Laser printing graphene on polyimide films is an efficient single-step fabrication process that can remedy this issue. A laser-printed, flexible pressure sensor is developed utilizing the piezoresistive effect of 3D porous graphene. The pressure sensors performance can be easily adjusted via the geometrical parameters. They have a sensitivity in the range of 1.23 × 10?3 kPa and feature a high resolution with a detection limit of 10 Pa in combination with an extremely wide dynamic range of at least 20 MPa. They also provide excellent long-term stability of at least 15 000 cycles. The biocompatibility of laser-induced graphene is also evaluated by cytotoxicity assays and fluorescent staining, which show an insignificant drop in viability. Polymethyl methacrylate coating is particularly useful for underwater applications, protecting the sensors from biofouling and shunt currents, and enable operation at a depth of 2 km in highly saline Red Sea water. Due to its features, the sensors are a prime choice for multiple healthcare applications; for example, they are used for heart rate monitoring, plantar pressure measurements, and tactile sensing.
关键词： laser printing,graphene,flexible devices,wearables,piezoresistive materials,pressure sensors
更新于2025-09-23 15:19:57
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Laser Enhanced Direct Print Additive Manufacturing of Embedded Circular Cross-Section Optical Fiber Interconnects for Board Level Computing Devices
摘要： Integrated photonics have many compelling advantages for computing and communication applications, including in high-speed and extremely wide bandwidth operations. Current systems are typically hybrid assemblies of packaged photonic devices where printed circuit boards often serve to route electrical signals and power, and in some cases, have runs of optical fibers. We present a flexible, low cost assembly method of optical interconnects for photonic systems that could enable higher transmission rates, lower power requirements, improved signal integrity and timing, less heat generation, and improved security of communication signals. The new process is based on laser enhanced direct print additive manufacturing (LE-DPAM) that combines fused deposition modeling (FDM) of plastic, micro-dispensing of rubber-like materials, and picosecond laser subtraction. The process is demonstrated by fabricating few-mode and multi-mode optical fibers in a controlled manner such that compact, 3-dimensional optical interconnects can be printed along non-lineal paths. We have produced working optical interconnects with fiber core diameters from 70-μm to as small as 12-μm. Our results demonstrate surface roughness of less than 100 nm, and optical transmitted power of 63% that of a commercial fiber, for proof of concept devices. We anticipate these devices to be a starting point in the development of more sophisticated electro-optical computing devices using this new LE-DPAM technique. The LE-DPAM approach could lead to large scale integrated photonic computing devices that would replace our current generation of servers, computers, and phones.
关键词： 3D printing,Optical fiber interconnects,Additive manufacturing,Laser enhanced direct print additive manufacturing
更新于2025-09-23 15:19:57