scholarly journals Effect of Process Parameters on Organic Micro Patterns Fabricated on a Flexible Substrate Using the Near-Field Electrohydrodynamic Direct-Writing Method

Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 287 ◽  
Author(s):  
Jianzhou Chen ◽  
Ting Wu ◽  
Libing Zhang ◽  
Peng Li ◽  
Xiaowei Feng ◽  
...  
Keyword(s):  
Process Parameters ◽  
Flow Rate ◽  
Applied Voltage ◽  
Flexible Substrate ◽  
Near Field ◽  
Injection System ◽  
Direct Writing ◽  
Micro Pattern ◽  
Mixed Material ◽  
Micro Patterns

A micro pattern is a key component of various functional devices. In the present study, using the poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) mixed material as the direct-writing solution and photographic paper as the flexible insulating substrate, the organic micro patterns of various shapes, such as the curve of the second-order self-similar structure, the helical curve, and the wave curve, were fabricated on the flexible insulating substrate by using the near-field electrohydrodynamic direct-writing method. The effects of process parameters, such as the applied voltage, direct-writing height, flow rate of the injection system, and moving velocity of the substrate, on the width and the conductivity of the organic micro patterns were studied in the near-field electrohydrodynamic direct-writing process. The results show that the width of an organic micro pattern increases with the increase of the applied voltage of the high-voltage power supplier and the flow rate of the injection system under the condition where the three other process parameters remained constant, respectively, while the width of an organic micro pattern decreases with the increase of the direct-writing height and the moving velocity of the flexible substrate, respectively. The fabricated organic microcircuit patterns of the natural drying in air at room temperature were tested by a thin film thermoelectric tester at a detection temperature. The results show that the conductivity of a fabricated organic micro pattern decreases with the increase of the electric field intensity, while the effect of moving velocity and the flow rate on the conductivity is small under the condition where the three other process parameters remained constant.

Influence of process parameters on the characteristics of electrohydrodynamic-printed UV-curing conductive lines on the fabric

2022 ◽  
Author(s):  
Wenjing Guo ◽  
Hu Jiyong ◽  
Xiong Yan
Keyword(s):  
Electrical Property ◽  
Line Width ◽  
Process Parameters ◽  
Flow Rate ◽  
Applied Voltage ◽  
Electrical Resistance ◽  
Uv Curing ◽  
Electrical Performance ◽  
Direct Writing ◽  
Printing Process

Abstract As a similar technology to the near-field static electrospinning, the emerging electrohydrodynamic (EHD) printing technology with digital printing process and compatibility of viscous particle-blended inks is one of the simplest methods of fabricating multifunctional electronic textiles.With increasing demands for textile-based conductive lines with controllable width and excellent electrical performance, it’s of great importance to know the influence of key process parameters on the morphology and electrical properties of EHD-printed UV-curing conductive lines on the fabric. This work will systematically explore the effect of the EHD printing process parameters (i.e. applied voltage, direct-writing height, flow rate and moving velocity of the substrate) on the morphology and electrical performance of the EHD-printed textile-based conductive lines, especially focus on the diffusion and penetration of inks on the rough and porous fabric. The UV-curing nano-silver ink with low temperature and fast curing features was selected, and the line width and electrical resistance of printed lines under different process parameters were observed and measured. The results showed that, unlike previous results about EHD printing on smooth and impermeable substrates, the ink diffusion related to fabric textures had a greater effect on the fabric-based conductive line width than the applied voltage and direct-writing height in the case of a stable jet. Meanwhile, the relationship between the line width and the flow rate met the equation of = 407.28 ∗ 1⁄2 , and the minimum volume on fabric per millimeter was 0.67μL to form continuous line with low electrical resistance. Additionally, the higher substrate moving velocity resulted in a smaller line width, while it deteriorated the thickness uniformity and electrical property of printed lines. Generally, due to the effect of surface structure of the fabric on the spreading and penetrating behavior of inks, the flow rate and the substrate moving velocity are two significant parameters ensuring the electrical property of printed lines. It is believed that these findings will provide some guides for applying electrohydrodynamic printing technology into flexible electronics on the woven fabric.

Design and fabrication of conductive nanofibrous scaffolds for neural tissue engineering: Process modeling via response surface methodology

2018 ◽  
Vol 33 (5) ◽  
pp. 619-629 ◽  
Author(s):  
Maryam Soleimani ◽  
Shohreh Mashayekhan ◽  
Hossein Baniasadi ◽  
Ahmad Ramazani ◽  
Mohamadhasan Ansarizadeh
Keyword(s):  
Nervous System ◽  
Response Surface Methodology ◽  
Peripheral Nervous System ◽  
Process Parameters ◽  
Flow Rate ◽  
Applied Voltage ◽  
Syringe Pump ◽  
Cell Compatibility ◽  
Nanofibrous Scaffolds ◽  
Pump Flow Rate

Peripheral nervous system in contrary to central one has the potential for regeneration, but its regrowth requires proper environmental conditions and supporting growth factors. The aim of this study is to design and fabricate a conductive polyaniline/graphene nanoparticles incorporated gelatin nanofibrous scaffolds suitable for peripheral nervous system regeneration. The scaffolds were fabricated with electrospinning and the fabrication process was designed with Design-Expert software via response surface methodology. The effect of process parameters including applied voltage (kV), syringe pump flow rate (cm3/h), and PAG concentration (wt%), on the scaffold conductivity, nanofibers diameter, and cell viability were investigated. The obtained results showed that the scaffold conductivity and cell viability are affected by polyaniline/graphene concentration while nanofiber diameter is more affected by the applied voltage and syringe pump flow rate. Optimum scaffold with maximum conductivity (0.031 ± 0.0013 S/cm) and cell compatibility and suitable diameter were electrospun according to the software introduced values for the process parameters (voltage of 13 kV, flow rate of 0.1 cm3/h, and PAG wt.% of 1.3) and its morphology, cell compatibility, and biodegradability were further investigated, which showed its potential for applying in peripheral nervous system injury regeneration.

scholarly journals The effect of process parameters on the electrospun polystyrene fibers

2018 ◽  
Vol 69 (04) ◽  
pp. 263-269
Author(s):  
BANCIU CRISTINA ◽  
BĂRA ADELA ◽  
CHIȚANU ELENA ◽  
MARINESCU VIRGIL ◽  
SBÂRCEA GABRIELA ◽  
...  
Keyword(s):  
Polymer Solution ◽  
Process Parameters ◽  
Flow Rate ◽  
Applied Voltage ◽  
Copper Substrate ◽  
Expanded Polystyrene ◽  
Electrospun Fibers ◽  
Polymeric Product ◽  
Economic Point ◽  
Small Pore

Electrospinning is one of the methods for obtaining nano/microfibers, using polymeric solutions. These nanofibrous membranes are highly porous with interconnected pores, having high specific surface area and small pore size, making them a suitable candidate for filtration applications. The properties of electrospun fibers are influenced by polymer solution, solvent, solution concentration, viscosity, electrical conductivity, electrical voltage, spinneret to collector distance etc. Expanded polystyrene is a polymeric product that is usually used for insulation and packaging. Recycling expanded polystyrene into nanofibers with applications in filtration could be useful from an economic point of view. The purpose of this study was to investigate the influence of expanded polystyrene polymer solution characteristics (concentration, viscosity) and the process parameters (applied voltage, distance between the tip and the collector plate, flow rate of the polymer solution) on the morphology and the properties of the obtained electrospun fibers. Therefore, three EPS solutions with 10, 15 and 20% wt. concentration were prepared and were electrospun under processing conditions with an applied voltage of 12, 15 and 18 kV, a spinneret-to-collector distance of 20 cm, a flow rate of solution of 1.5 and 2 mL/hour, a spinneret diameter of 0.8 mm and stationary copper substrate. The morphology of the electrospun fibers was observed by scanning electron microscopy. The mechanical properties were evaluated by tensile strength and elongation tests.

Effect of Applied Voltage on Polymer Aggregation in Electrospraying of Thermoplastic Polymer

2012 ◽  
Vol 535-537 ◽  
pp. 2522-2525 ◽  
Author(s):  
Amit Jadhav ◽  
Li Jing Wang ◽  
Rajiv Padhye
Keyword(s):  
Process Parameters ◽  
Flow Rate ◽  
Applied Voltage ◽  
Solution Concentration ◽  
Solution Flow Rate ◽  
Thermoplastic Polymer ◽  
Solution Flow ◽  
Polymer Liquids ◽  
Polymeric Solutions ◽  
Uniform Droplets

In an electrospraying process, the polymer solution interacts with the electric field. Charged polymeric solutions causing polymer liquids to move, break into drops or spray into fine droplets. Electrospraying has the ability to generate very small & uniform droplets of polymeric solution. It is envisaged that electrospraying is a promising technology to coat a polymer on surface at submicron range. The polymer aggregation is important while coating. The process parameters including applied voltage, nozzle-collector distance, solution flow rate, and solution concentration play an important role in polymer droplets aggregation on surface. This research paper investigates the effect of applied voltage on aggregation of polymer droplets.

scholarly journals Optical Sensitivity of Waveguides Inscribed in Nanoporous Silicate Framework

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 123
Author(s):  
Zhong Lijing ◽  
Roman A. Zakoldaev ◽  
Maksim M. Sergeev ◽  
Andrey B. Petrov ◽  
Vadim P. Veiko ◽  
...  
Keyword(s):  
Refractive Index ◽  
Near Field ◽  
Experimental Studies ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Direct Writing ◽  
Sensor Applications ◽  
Refractive Index Contrast ◽  
Optical Sensitivity ◽  
Index Contrast

Laser direct writing technique in glass is a powerful tool for various waveguides’ fabrication that highly develop the element base for designing photonic devices. We apply this technique to fabricate waveguides in porous glass (PG). Nanoporous optical materials for the inscription can elevate the sensing ability of such waveguides to higher standards. The waveguides were fabricated by a single-scan approach with femtosecond laser pulses in the densification mode, which resulted in the formation of a core and cladding. Experimental studies revealed three types of waveguides and quantified the refractive index contrast (up to Δn = 1.2·10−2) accompanied with ~1.2 dB/cm insertion losses. The waveguides demonstrated the sensitivity to small objects captured by the nanoporous framework. We noticed that the deposited ethanol molecules (3 µL) on the PG surface influence the waveguide optical properties indicating the penetration of the molecule to its cladding. Continuous monitoring of the output near field intensity distribution allowed us to determine the response time (6 s) of the waveguide buried at 400 µm below the glass surface. We found that the minimum distinguishable change of the refractive index contrast is 2 × 10−4. The results obtained pave the way to consider the waveguides inscribed into PG as primary transducers for sensor applications.

Active Control of Fabricating Nanofibrous Wavy/Helical Arrays Using Near-Field Electrospinning

2018 ◽  
Author(s):  
Xiangyu You ◽  
Ping Guo
Keyword(s):  
Active Control ◽  
Process Parameters ◽  
Electric Field Distribution ◽  
Structural Parameters ◽  
Near Field ◽  
Stretchable Electronics ◽  
Time Varying ◽  
Photovoltaic Devices ◽  
Feature Size ◽  
Experimental Process

A novel and simple near-field electrospinning (NFES) method has been developed to fabricate wavy or helical nanofibrous arrays. By alternating the electrostatic signals applied on auxiliary-electrodes (AE), the structural parameters of deposited patterns can be actively controlled. Compared with the traditional electrospinning methods based on the bending and buckling effects or collector movement, the proposed method shows advantages in the controllability, accuracy, and minimal feature size. Forces operating on the electrospinning jet and the time-varying electric field distribution were analyzed to explain the kinematics of the jet. Nanoscale wavy and helical patterns with various structural parameters were fabricated. The effects of experimental process parameters on structural parameters of deposited patterns were analyzed to demonstrate the controllability of our method in fabricating wavy or helical nanofibrous structures. It is envisioned that this method will benefit the applications in the field of photovoltaic devices, sensors, transducers, resonators, and stretchable electronics.

scholarly journals Electropolishing Parametric Optimization of Surface Quality for the Fabrication of a Titanium Microchannel Using the Taguchi Method

Machines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 325
Author(s):  
Muslim Mahardika ◽  
Martin Andre Setyawan ◽  
Tutik Sriani ◽  
Norihisa Miki ◽  
Gunawan Setia Prihandana
Keyword(s):  
Taguchi Method ◽  
Surface Quality ◽  
Process Parameters ◽  
Applied Voltage ◽  
High Surface ◽  
Machining Process ◽  
Machining Parameters ◽  
Pareto Analysis ◽  
High Surface Quality

Titanium is widely used in biomedical components. As a promising advanced manufacturing process, electropolishing (EP) has advantages in polishing the machined surfaces of material that is hard and difficult to cut. This paper presents the fabrication of a titanium microchannel using the EP process. The Taguchi method was adopted to determine the optimal process parameters by which to obtain high surface quality using an L9 orthogonal array. The Pareto analysis of variance was utilized to analyze the three machining process parameters: applied voltage, concentration of ethanol in an electrolyte solution, and machining gap. In vitro experiments were conducted to investigate the fouling effect of blood on the microchannel. The result shows that an applied voltage of 20 V, an ethanol concentration of 20 vol.%, and a machining gap of 10 mm are the optimum machining parameters by which to enhance the surface quality of a titanium microchannel. Under the optimized machining parameters, the surface quality improved from 1.46 to 0.22 μm. Moreover, the adhesion of blood on the surface during the fouling experiment was significantly decreased, thus confirming the effectiveness of the proposed method.

scholarly journals Processing variables of direct-write, near-field electrospinning impact size and morphology of gelatin fibers

2020 ◽  
Author(s):  
Zachary G. Davis ◽  
Aasim F. Hussain ◽  
Matthew B. Fisher
Keyword(s):  
Acetic Acid ◽  
Acid Concentration ◽  
Near Field ◽  
Fiber Formation ◽  
Direct Write ◽  
Acetic Acid Concentration ◽  
Direct Writing ◽  
Fiber Morphology ◽  
Gelatin Concentration ◽  
The Impact

AbstractSeveral biofabrication methods are being investigated to produce scaffolds that can replicate the structure of the extracellular matrix. Direct-write, near-field electrospinning of polymer solutions and melts is one such method which combines fine fiber formation with computer-guided control. Research with such systems has focused primarily on synthetic polymers. To better understand the behavior of biopolymers used for direct-writing, this project investigated changes in fiber morphology, size, and variability caused by varying gelatin and acetic acid concentration, as well as, process parameters such as needle gauge and height, stage speed, and interfiber spacing. Increasing gelatin concentration at a constant acetic acid concentration improved fiber morphology from large, planar structures to small, linear fibers with a median of 2.3 µm. Further varying the acetic acid concentration at a constant gelatin concentration did not alter fiber morphology and diameter throughout the range tested. Varying needle gauge and height further improved the median fiber diameter to below 2 µm and variability of the first and third quartiles to within +/-1 µm of the median for the optimal solution combination of gelatin and acetic acid concentrations. Additional adjustment of stage speed did not impact the fiber morphology or diameter. Repeatable interfiber spacings down to 250 µm were shown to be capable with the system. In summary, this study illustrates the optimization of processing parameters for direct-writing of gelatin to produce fibers on the scale of collagen fibers. This system is thus capable of replicating the fibrous structure of musculoskeletal tissues with biologically relevant materials which will provide a durable platform for the analysis of single cell-fiber interactions to help better understand the impact scaffold materials and dimensions have on cell behavior.

Development of a Method to Evaluate CNG-Injection Valves

2015 ◽  
Author(s):  
Christian von Grabe ◽  
David van Bebber ◽  
Hubertus Murrenhoff
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Test Chamber ◽  
Combustion Process ◽  
Test Method ◽  
Injection System ◽  
Time Behavior ◽  
Gaseous Fuels ◽  
Injection Process

The development of combustion engines with direct injection requires a comprehensive knowledge of the in cylinder combustion process as well as the used high pressure injection system. One main characteristic of injection systems is their mass flow over time behavior. For prevalent diesel and gasoline injection valves (injectors) fully developed simulation models as well as test benches are available to analyze the injection process. Besides the established engines a trend towards compressed natural gas (CNG) engines in passenger cars is recognized. Due to the small injection duration of a few milliseconds, the flow rate measurement is particularly challenging and requires highly dynamic measuring. The existing test benches are designed and optimized for liquid fuels and are only partly suitable for the evaluation of gaseous fuels such as CNG. A typical test method is to inject fuel into a long tube in which a pressure wave propagates. Based on the pressure signal the mass flow of the injected fuel is approximated. For gaseous fuels the correlation of mass flow and pressure propagation is only known for specific test cases and therefore the method is not directly applicable to gaseous fuels. This paper presents a newly designed measurement device to evaluate the mass flow rate as well as the injector needle displacement during an injection process of gaseous fuels. The test bench is designed to operate in a fully equipped injection system including gas lines, common rail and injection valves, to also investigate the interaction of the individual system components. The design is based on a closed test chamber in which the pressure rises during the injection. To overcome the influence of propagating pressure waves inside the chamber on the measurement, different chamber designs are evaluated. An optimized design, separating the chamber into two volumes which are connected by a damping sleeve, is presented. The injection itself is carried out in a first volume and the measurement is conducted in a second damped volume. Based on the measured pressure the mass flow rate through the injection valve is approximated, utilizing the equations of thermodynamics.

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