Fabrication of the large-area flexible transparent heaters using electric-field-driven jet deposition micro-scale 3D printing

2019 ◽  
Vol 8 (3-4) ◽  
pp. 217-223 ◽  
Author(s):  
Hefei Zhou ◽  
Xiaoyang Zhu ◽  
Hongke Li ◽  
Hongbo Lan
Keyword(s):  
3D Printing ◽  
Electric Field ◽  
Sheet Resistance ◽  
Heating Temperature ◽  
Low Cost ◽  
Optical Transmittance ◽  
Adhesive Force ◽  
High Viscosity ◽  
Large Area ◽  
Micro Scale

Abstract In order to realize the mass production of the large-area flexible transparent film heater (FTFH) at low-cost, this paper presents a novel method which can achieve the direct fabrication of the large-area FTFH with Ag-grid by using an electric-field-driven jet deposition micro-scale 3D printing. The effects of the line width and the pitch of the printed Ag-grids on the optical transmittance and the sheet resistance are revealed. A typical FTFH with area of 80 mm × 60 mm, optical transmittance of 91.5% and sheet resistance of 4.7 Ω sq−1 is fabricated by the nano-silver paste with a high silver content (80 wt.%) and high viscosity (up to 20 000 mPa · s). Temperature-time response profiles and heating temperature distribution show that the heating performance of the FTFH has good thermal and mechanical properties. Furthermore, the adhesive force grade between the Ag-grid and the PET substrate measured to be 4B by 3M scotch tape. Therefore, the FTFH fabricated here is expected to be widely used in industry, such as window defroster of vehicles and display or touch screens owing to its striking characteristics of large area and low cost fabrication.

A Novel Microscale 3D Printing Based on Electric-Field-Driven Jet Deposition

2018 ◽  
Author(s):  
Lei Qian ◽  
Hongbo Lan ◽  
Guangming Zhang ◽  
Jiawei Zhao ◽  
Shuting Zou
Keyword(s):  
3D Printing ◽  
Electric Field ◽  
Low Cost ◽  
Experimental Studies ◽  
Counter Electrodes ◽  
Micro Scale ◽  
Multi Scale ◽  
Printing Technique ◽  
Jet Printing ◽  
3D Printing Technique

This paper presents an electric-field-driven (EFD) jet deposition 3D printing technique, which is based on the induced electric field and electrohydrodynamic (EHD) cone-jetting behavior. Unlike the traditional EHD-jet printing with two counter electrodes, the EFD jet 3D printing only requires a nozzle electrode to induce an electric field between the nozzle and the target substrate. Taking into account both printing accuracy and printing efficiency, two novel working modes which involve pulsed cone-jet mode and continuous cone-jet mode, are proposed for implementing multi-scale 3D printing. In this work, significant relationships between the printing results and process parameters (voltage, air pressure, pulse duration time, and stage velocity) were investigated to guide the reliable printing in both working modes. Furthermore, the experimental studies were carried out to demonstrate the capabilities and advantages of the proposed approach, which included the suitability of various substrate, the capacity of conformal printing, and the diversity of the compatible materials. Finally, four typical printing results were provided to demonstrate the feasibility and effectiveness of the proposed technology for micro-scale 2D patterning and macro/microstructures multi-scale fabrication. As a result, this research provides a novel micro-scale 3D printing technique with low cost, high resolution and good generalizability. The breakthrough technique paves a way for implementing highresolution 3D printing, especially for multi-scale and multimaterial additive manufacturing.

scholarly journals The Electric-Field-Driven Fusion Jetting 3D Printing for Fabricating High Resolution Polylactic Acid/Multi-Walled Carbon Nanotube Composite Micro-Scale Structures

Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1132
Author(s):  
Xiaoqiang Li ◽  
Guangming Zhang ◽  
Wenhai Li ◽  
Zun Yu ◽  
Kun Yang ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
High Resolution ◽  
3D Printing ◽  
Electric Field ◽  
Polylactic Acid ◽  
Line Width ◽  
Micro Scale ◽  
Biomimetic Scaffolds ◽  
Multi Walled Carbon Nanotube ◽  
Scale Structures

Existing 3D printing techniques are still facing the challenge of low resolution for fabricating polymer matrix composites, inhibiting the wide engineering applications for the biomedical engineering (biomimetic scaffolds), micro fuel cells, and micro-electronics. In order to achieve high resolution fabrication of polylactic acid (PLA)/multi-walled carbon nanotube (MWCNT) composites, this paper presents an electric-field-driven (EFD) fusion jetting 3D printing method by combining the mixing effect and material feeding of the micro-screw and the necking effect of Taylor cone by the EFD. The effects of main process parameters (the carbon loading, the voltage, the screw speed, and the printing speed) on the line width and the printing quality were studied and optimized. To demonstrate the printing capability of this proposed method, meshes with line width of 30 µm to 100 μm and 1 wt.% to 5 wt.% MWCNT for the application of conductive biomimetic scaffold and the anisotropic flexible meshes were prepared. The electrical properties were investigated to present the frequency dependence of the alternating current conductivity and the dielectric loss (tanδ), and the microstructures of printed structures demonstrated the uniformly dispersed MWCNT in PLA matrix. Therefore, it provides a new solution to fabricate micro-scale structures of composite materials, especially the 3D conductive biomimetic scaffolds.

scholarly journals Preparation of Nano Silver Paste and Applications in Transparent Electrodes via Electric-Field Driven Micro-Scale 3D Printing

Nanomaterials ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 107 ◽  
Author(s):  
Hongke Li ◽  
Xiaoyang Zhu ◽  
Zhenghao Li ◽  
Jianjun Yang ◽  
Hongbo Lan
Keyword(s):  
3D Printing ◽  
Electric Field ◽  
Solid Content ◽  
No Oxidation ◽  
Basic Material ◽  
Transparent Electrodes ◽  
Printing Technology ◽  
Silver Paste ◽  
Nano Silver ◽  
Micro Scale

Nano-silver paste, as an important basic material for manufacturing thick film components, ultra-fine circuits, and transparent conductive films, has been widely used in various fields of electronics. Here, aiming at the shortcomings of the existing nano-silver paste in printing technology and the problem that the existing printing technology cannot achieve the printing of high viscosity, high solid content nano-silver paste, a nano-silver paste suitable for electric-field-driven (EFD) micro-scale 3D printing is developed. The result shows that there is no oxidation and settlement agglomeration of nano-silver paste with a storage time of over six months, which indicates that it has good dispersibility. We focus on the printing process parameters, sintering process, and electrical conductivity of nano-silver paste. The properties of the nano-silver paste were analyzed and the feasibility and practicability of the prepared nano-silver paste in EFD micro-scale 3D printing technology were verified. The experiment results indicate that the printed silver mesh which can act as transparent electrodes shows high conductivity (1.48 Ω/sq) and excellent transmittance (82.88%). The practical viability of the prepared nano-silver paste is successfully demonstrated with a deicing test. Additionally, the experimental results show that the prepared silver mesh has excellent heating properties, which can be used as transparent heaters.

scholarly journals Theoretical Uniformity Analysis and Improvement of Spray Deposition by Mixing Nozzles with Heating Conditions

Coatings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 81
Author(s):  
Xuran Dong ◽  
Xiaolong Pan ◽  
Xianxian Gao ◽  
Haisheng Fang
Keyword(s):  
High Speed ◽  
Heating Temperature ◽  
Spray Deposition ◽  
Low Cost ◽  
Spray Coating ◽  
Deposition Process ◽  
Test Method ◽  
Large Area ◽  
Orthogonal Test Method ◽  
Experimental Trials

Spray coating is widely used in the manufacture of deposited layers of electronic devices due to its unique advantages of high-speed deposition over a large area. To improve the spray deposition process for further low-cost and uniform production, the uniformity of the spray deposition should be systematically investigated. The current study, however, mainly focuses on the experimental trials with few numerical directions especially for the mixing nozzle sprayers with heating conditions. In the paper, we conduct a theoretical study on the uniformity of the internal and external mixing nozzles. The influencing factors include the initial angle, the total ink flow rate, the transporting gas velocity and the distance from the nozzle to the substrate. Then, the orthogonal test method is adopted to obtain the optimal combination of the parameters. Finally, the effects of different heating modes on the uniformity have been further studied. The results show that these factors influence the uniformity with the two types of nozzles to a different degree. The evaporation of the atomized droplets can effectively improve the uniformity in a certain temperature range. The heating temperature with the highest uniformity is various depending on the heating modes, which should be carefully addressed during the actual production.

scholarly journals Metal-mesh Transparent EMI Shielding Glass Fabricated by Electric-field-driven Jet Deposition Micro-scale 3D Printing

2019 ◽  
Vol 55 (15) ◽  
pp. 56
Author(s):  
ZHOU Hefei ◽  
LAN Hongbo ◽  
LI Hongke ◽  
XU Quan ◽  
ZHAO Jiawei ◽  
...  
Keyword(s):  
3D Printing ◽  
Electric Field ◽  
Emi Shielding ◽  
Metal Mesh ◽  
Micro Scale

scholarly journals Spray Deposition of Ag Nanowire–Graphene Oxide Hybrid Electrodes for Flexible Polymer–Dispersed Liquid Crystal Displays

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2231 ◽  
Author(s):  
Yumi Choi ◽  
Chang Kim ◽  
Sungjin Jo
Keyword(s):  
Optical Properties ◽  
Graphene Oxide ◽  
Sheet Resistance ◽  
Indium Tin Oxide ◽  
Spray Deposition ◽  
Spray Coating ◽  
Optical Transmittance ◽  
Large Area ◽  
Flexible Polymer ◽  
Polymer Dispersed

We investigated the effect of different spray-coating parameters on the electro-optical properties of Ag nanowires (NWs). Highly transparent and conductive Ag NW–graphene oxide (GO) hybrid electrodes were fabricated by using the spray-coating technique. The Ag NW percolation network was modified with GO and this led to a reduced sheet resistance of the Ag NW–GO electrode as the result of a decrease in the inter-nanowire contact resistance. Although electrical conductivity and optical transmittance of the Ag NW electrodes have a trade-off relationship, Ag NW–GO hybrid electrodes exhibited significantly improved sheet resistance and slightly decreased transmittance compared to Ag NW electrodes. Ag NW–GO hybrid electrodes were integrated into smart windows based on polymer-dispersed liquid crystals (PDLCs) for the first time. Experimental results showed that the electro-optical properties of the PDLCs based on Ag NW–GO electrodes were superior when compared to those of PDLCs based on only Ag NW electrodes. This study revealed that the hybrid Ag NW–GO electrode is a promising material for manufacturing the large-area flexible indium tin oxide (ITO)-free PDLCs.

3D Additive Manufacturing and Micro-Assembly for Transfection of 3D-Cultured Cells and Tissues

2018 ◽  
Author(s):  
Qingfu Zhu ◽  
Ziyu Zhu ◽  
Mei He
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Electric Field ◽  
Cultured Cells ◽  
Transfection Efficiency ◽  
Low Cost ◽  
3D Cell Culture ◽  
Electric Transport

3D additive manufacturing, namely 3D printing, has been increasingly needed in the fabrication of biological materials and devices. Compared to traditional fabrication, direct 3D digital transformation simplifies the manufacturing process and enhances capability in geometric fabrication. In this paper, we demonstrated a rapid and low-cost 3D printing approach for “lego” assembly of micro-structured parts as an electro-transfection device. Electro-transfection is an essential equipment for engineering and regulating cell biological functions. Nevertheless, existing platforms are mainly employed to monolayer cell suspensions in vitro, which showed more failures for translating into tissues and in vivo systems constituted by 3D cells. The knowledge regarding the three-dimensional electric transport and distribution in a tissue microenvironment is lacking. In order to bridge the gap, we assembled PDMS parts molded from 3D-printed molds as the 3D-cell culture chamber, which connects arrays of perfusion channels and electrodes. Such design allows spatial and temporal control of electric field uniformly across a large volume of 3D cells (105∼106 cells). Most importantly, multi-dimensional electric frequency scanning creates local oscillation, which can enhance mass transport and electroporation for improving transfection efficiency. The COMSOL electrostatic simulation was employed for proof of concept of 3D electric field distribution and transport in this “lego” assembled electro-transfection device, which builds the foundation for engineering 3D-cultured cells and tissues.

scholarly journals Flexible biodegradable transparent heaters based on fractal-like leaf skeletons

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Vipul Sharma ◽  
Anastasia Koivikko ◽  
Kyriacos Yiannacou ◽  
Kimmo Lahtonen ◽  
Veikko Sariola
Keyword(s):  
Surface Temperature ◽  
Surface Area ◽  
Sheet Resistance ◽  
Flexible Electronics ◽  
Low Voltage ◽  
Heating Temperature ◽  
Optical Transmittance ◽  
Ag Nanowires ◽  
Significant Change

Abstract We present a facile method to prepare flexible, transparent, biodegradable, and fast resistive heaters by applying silver (Ag) nanowires onto fractal-like leaf skeletons. The fractal-like structure of the leaf skeleton maximizes its surface area, improving the transfer of heat to its surroundings and thus making the heater fast, without compromising transparency. Ag ion layer on the leaf skeleton helps to conformally cover the surface with Ag nanowires. The sheet resistance of the heater can be controlled by the loading of Ag nanowires, without sacrificing the optical transmittance (~80% at 8 Ω sq−1). The heating is uniform and the surface temperature of a 60 mm × 60 mm heater (8 Ω sq−1) can quickly (5–10 s) raise to 125 °C with a low voltage (6 V). The heater displays excellent mechanical flexibility, showing no significant change in resistance and heating temperature when bent up to curvature of 800 m−1. Finally, we demonstrate the potential of the bioinspired heater as a thermotherapy patch by encapsulating it in a biodegradable tape and mounting it on the human wrist and elbow. This study shows that fractal-like structures from nature can be repurposed as fractal designs for flexible electronics.

Micro-Scale Manufacture of 3D Printing

2014 ◽  
Vol 670-671 ◽  
pp. 936-941 ◽  
Author(s):  
Yi Ping Chen ◽  
Ming Der Yang
Keyword(s):  
3D Printing ◽  
3D Modeling ◽  
3D Model ◽  
Low Cost ◽  
3D Models ◽  
Micro Scale ◽  
Active Approach ◽  
Real Objects ◽  
Barrier To Entry ◽  
Great Possibility

3D printing as additive manufacturing enables to give concept proposers and designers a great possibility of producing physical parts and concept models at acceptable cost during a short time. Such technology is quite distinct from traditional machining techniques adopting subtractive process. The purpose of this study is to briefly describe new micro-scale manufacture utilizing a series of process of 3D printing, including 3D modeling, 3D model slicing, printing, and products. Especially, 3D modeling is one of major components in 3D printing process and becomes a barrier to entry the business of micro-scale manufacture for everyone with a 3-D printer. This paper introduces two low-cost approaches to generate 3D models, including active and passive approaches. 3D scanning as an active approach allows the replication of real objects without the need of moulding techniques. On the other hand, image-based modeling as a passive is an alternative of un-touch model reconstruction without a threat of destructive impact to the modeled object. Also, a statue in gypsum was made by a 3D printer based on a digital 3D model generated through the low-cost active approach for demonstration.

scholarly journals Fabrication of a Large-Area, Fused Polymer Micromold Based on Electric-Field-Driven (EFD) μ-3D Printing

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1902 ◽  
Author(s):  
Zilong Peng ◽  
Nairui Gou ◽  
Zilong Wei ◽  
Jiawei Zhao ◽  
Fei Wang ◽  
...  
Keyword(s):  
3D Printing ◽  
Electric Field ◽  
Field Distribution ◽  
Manufacturing Industry ◽  
Electric Field Distribution ◽  
Polymer Materials ◽  
Large Area ◽  
Mesh Structure ◽  
Key Factor ◽  
Order Of Magnitude

An electric-field-driven (EFD), μ-3D printed, fused polymer technique has been developed for the fabrication of large-area microscale prototype molds using typical polymer materials, including microcrystalline wax (MC-wax), polycaprolactone (PCL), and polymathic methacrylate (PMMA). This work proposes an alternative for large area microscale modes and overcomes the limitation of high cost in the traditional mold manufacturing industry. The EFD principle enables printing of fused polymers materials more than one order of magnitude lower than the nozzle diameter, contributing to the necking effect of the Taylor cone jet, which is the key factor to achieve the microscale manufacturing. Numerical simulation of electric field distribution between the meniscus and substrate was carried out to elucidate the dependence of electric field distribution on the meniscus condition of three types of polymers under printable voltage, and the electrical field parameters for the EFD μ-3D printing were determined. A number of experiments were printed successfully using a large range of viscosity materials, ranging from tens of mPa·s to hundreds of thousands of mPa·s of PCL and PMMA. The differences in parameters of different materials, such as viscosity, tensile properties, and surface energy, were studied to assess their use in different fields. Using proper process parameters and a nozzle with an inner diameter of 200 μm, three different application cases were completed, including a Wax microarray and microchannel with a minimum dot diameter of 20 μm, a PCL mesh structure with a minimum line width of 5 μm, and a PMMA large-area mold with a maximum aspect ratio of 0.8. Results show that the EFD μ-3D printing has the outstanding advantages of high printing resolution and polymer material universality.

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