scholarly journals Influence and evaluation of array-nozzle geometry on near- field electrospinning direct writing

2019 ◽  
Vol 14 ◽  
pp. 155892501989564
Author(s):  
Jiarong Zhang ◽  
Han Wang ◽  
Zhifeng Wang ◽  
Honghui Yao ◽  
Guojie Xu ◽  
...  
Keyword(s):  
Electric Field ◽  
Near Field ◽  
Microfluidic Channel ◽  
Nozzle Geometry ◽  
Direct Writing ◽  
Large Area ◽  
Linear Arrangement ◽  
Nozzle Length ◽  
Aligned Fibers ◽  
Nozzle Spacing

Near-field electrospinning direct writing of array-nozzle is an efficient method for preparing large-area aligned fibers. However, electric field between the array-nozzle interferes with the stability and uniformity of near-field electrospinning, and little research has been done in this field. To clarify the electric field interference generated by array-nozzle, the experimental results compared with the simulation are discussed. In this work, electric field interference between the five-nozzle linear arrangement near-field electrospinning process was demonstrated by the initial ejection behavior, the electric field distribution of near-field electrospinning environment and the deposition spacing of fibers. In addition, we developed a simple and flexible method serving as a quantitative evaluation index for evaluating the degree of electric field interference. Then, the mapping effects of electric field interference of nozzle structure on the surface morphology and uniformity of aligned fibers were studied, including the number of nozzle, nozzle spacing and nozzle length with linear and toothed arrangement. According to the result of experiment and characterization, suitable arrayed nozzle parameters for stably direct-write aligned array pattern with near-field electrospinning were available, whose geometric parameters are linear two-nozzle with a nozzle spacing of 2 mm and a nozzle length of 6.35 mm. Finally, on the basis of our previous research, a microfluidic channel was successfully prepared on polydimethylsiloxane by two-nozzle cooperation, which verified the rationality of the geometry.

scholarly journals Accurate fabrication of aligned nanofibers via a double-nozzle near-field electrospinning

2019 ◽  
Vol 23 (4) ◽  
pp. 2143-2150 ◽  
Author(s):  
Guojie Xu ◽  
Han Wang ◽  
Zhifeng Wang ◽  
Jiarong Zhang ◽  
Rouxi Chen ◽  
...  
Keyword(s):  
Energy Harvester ◽  
Near Field ◽  
Wearable Sensors ◽  
Electrospinning Process ◽  
High Tech ◽  
Direct Write ◽  
Large Area ◽  
Aligned Nanofibers ◽  
Aligned Fibers ◽  
Key Factor

The near-field electrospinning is considered as one of the most effective techniques to direct-write aligned fibers which can be applied to various high-tech areas, including energy harvester, tissue engineering, and wearable sensors. For large area aligned pattern printing, the multi-nozzle electrohydrodynamic print-ing is an efficient method to enhance productivity. As a branch of electrohydro-dynamic printing technology, the near-field electrospinning is a crucial concern to make an investigation for the formation of aligned nanofibers. Here we fabricated various nanostructures from beaded fibers to aligned fibers and crimped fibers by the double-nozzle near-field electrospinning process. We found three key parameters affecting the process, including the collector speed, the applied voltage, and the electrode-to-collector distance, and the collector speed is the key factor affecting the crimped frequency. This paper provides a reliable experi-mental basis and theoretical guidance for the multi-nozzle near-field electrospin-ning to accurately direct-write microfibers and nanofibers.

Manufacturing of Submicrofluidic Channels Based on Near-field Electrospinning with PEO

2020 ◽  
Vol 12 (3) ◽  
pp. 243-246
Author(s):  
Jiarong Zhang ◽  
Han Wang ◽  
Zhifeng Wang ◽  
Honghui Yao ◽  
Guojie Xu ◽  
...  
Keyword(s):  
Near Field ◽  
Three Dimensional ◽  
Microfluidic Channel ◽  
Microfluidic Channels ◽  
Direct Writing ◽  
Micro Electro Mechanical Systems ◽  
Three Dimensional Printing ◽  
Complex Process ◽  
Pdms Molding ◽  
Dimensional Printing

Background: Microfluidic channels have been widely applied in biomedicine and microelectronics. However, the manufacturing methods of microfluidic channel devices, such as photolithography, three-dimensional printing and Melt-electrospinning direct writing (MEDW), have the problem of high cost and complex process, which still can't reach a sub-micron scale stably. Method: To improve the resolution of microfluidic channels, we developed a simple and flexible method to fabricate polydimethylsiloxane (PDMS) submicrofluidic channels. It depends on the following steps: (1) Direct Writing Polyethylene oxide (PEO) nanofiber by Near-field Electrospinning (NFES). (2) Packaging the nanofiber with PDMS. (3) Obtaining the PDMS submicrofluidic channel by inverted mode of PEO nanofiber. Results: According to the result of the experiment, nanofiber can be stably prepared under the following conditions, the electrode-to-collector distance of 3.0 mm, the voltage of 1.7 KV, the collector moving speed of 80mm/s and the mixed solutions of ethanol and deionized water (1:1). Finally, the PDMS submicrofluidic channel was manufactured by NFES and PDMS molding technique, and the diameter of the channel was 0.84±0.08 μm. Conclusion: The result verified the rationality of that method. In addition, the method can be easily integrated with high resolution channels for various usages, such as microelectronics, micro electro mechanical systems, and biomedical.

Research on Deposition Characteristics of the Double-Nozzle in Near-Field Electrospinning

2016 ◽  
Vol 679 ◽  
pp. 59-62 ◽  
Author(s):  
Zhi Feng Wang ◽  
Xin Du Chen ◽  
Shen Neng Huang ◽  
Fei Yu Fang ◽  
Han Wang
Keyword(s):  
Electric Field ◽  
Field Intensity ◽  
Manufacturing Process ◽  
Electric Field Intensity ◽  
Near Field ◽  
Force Distribution ◽  
Needle Length ◽  
Nozzle Length ◽  
Deposition Distance

With the double-nozzle NFES process, the uncertainty is more suitable to investigate than the multi-nozzle NFES and also meet higher liquid throughput requirement than conventional electrospinning. Moreover, the key point is to control the deposition characteristics of double-nozzle NFES under the interaction of the nozzles. This paper simulates the change in electric field intensity with the change of nozzle length and voltage. The experiment shows that the deposition distance becomes smaller when needle length increases, however, the influence of voltage is opposite in certain range. According to the study above, the results could be the guidance of the multi-nozzles NEFS in manufacturing process, and also can illustrate the force distribution of the jet with further modification.

Feasibility of Fiber-Deposition Control by Secondary Electric Fields in Near-Field Electrospinning

2015 ◽  
Vol 3 (4) ◽  
Author(s):  
Nicolas Martinez-Prieto ◽  
Maxwell Abecassis ◽  
Jiachen Xu ◽  
Ping Guo ◽  
Jian Cao ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Near Field ◽  
3D Structure ◽  
Flight Path ◽  
Auxiliary Electrode ◽  
Direct Writing ◽  
Real Time Control ◽  
Structure Generation ◽  
Fiber Deposition

Product miniaturization has become a trending technology in a broad range of industries and its development is being pushed by the requirements for complexity and resolution of micromanufactured products. However, there still exists a gap in the manufacturing spectrum for complex three-dimensional (3D) structure generation capabilities with micron and submicron resolution. This paper extends the near-field electrospinning (NFES) process and develops a direct-writing (DW) technology for microfiber deposition with micrometer resolution. The proposed method presented uses an auxiliary electrode to generate an electric field perpendicular to the fiber flight path. This tunable electric field grants the user real-time control of the fiber flight path, increasing the resolution of the deposited structure. The use of an auxiliary electrode ring for fiber manipulation is proposed to further improve control over the deposition process.

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.

Atomic 2D electric field imaging of a Yagi–Uda antenna near-field using a portable Rydberg-atom probe and measurement instrument

2020 ◽  
Vol 9 (5) ◽  
pp. 305-312
Author(s):  
Ryan Cardman ◽  
Luís F. Gonçalves ◽  
Rachel E. Sapiro ◽  
Georg Raithel ◽  
David A. Anderson
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Field Measurement ◽  
Near Field ◽  
Measurement Instrument ◽  
Rydberg Atom ◽  
Field Measurements ◽  
Atom Probe ◽  
Electric Field Measurement ◽  
Measurement Uncertainties

AbstractWe present electric field measurements and imaging of a Yagi–Uda antenna near-field using a Rydberg atom–based radio frequency electric field measurement instrument. The instrument uses electromagnetically induced transparency with Rydberg states of cesium atoms in a room-temperature vapor and off-resonant RF-field–induced Rydberg-level shifts for optical SI-traceable measurements of RF electric fields over a wide amplitude and frequency range. The electric field along the antenna boresight is measured using the atomic probe at a spatial resolution of ${\lambda }_{RF}/2$ with electric field measurement uncertainties below 5.5%, an improvement to RF measurement uncertainties provided by existing antenna standards.

Pattern Writing by Implantation in a Large-Scale PSII System With Planar Inductively Coupled Plasma Source

2000 ◽  
Vol 624 ◽  
Author(s):  
Lingling Wu ◽  
Hongjun Gao ◽  
Dennis M. Manos
Keyword(s):  
Inductively Coupled Plasma ◽  
Large Scale ◽  
Lateral Diffusion ◽  
Plasma Source ◽  
Direct Writing ◽  
Large Area ◽  
Depth Profiles ◽  
Geometric Patterns ◽  
Planar Coil ◽  
Rf Antenna

ABSTRACTA large-scale plasma source immersion ion implantation (PSII) system with planar coil RFI plasma source has been used to study an inkless, deposition-free, mask-based surface conversion patterning as an alternative to direct writing techniques on large-area substrates by implantation. The apparatus has a 0.61 m ID and 0.51 m tall chamber, with a base pressure in the 10−8 Torr range, making it one of the largest PSII presently available. The system uses a 0.43 m ID planar rf antenna to produce dense plasma capable of large-area, uniform materials treatment. Metallic and semiconductor samples have been implanted through masks to produce small geometric patterns of interest for device manufacturing. Si gratings were also implanted to study application to smaller features. Samples are characterized by AES, TEM and variable-angle spectroscopic ellipsometry. Composition depth profiles obtained by AES and VASE are compared. Measured lateral and depth profiles are compared to the mask features to assess lateral diffusion, pattern transfer fidelity, and wall-effects. The paper also presents the results of MAGIC calculations of the flux and angle of ion trajectories through the boundary layer predicting the magnitude of flux as a function of 3-D location on objects in the expanding sheath

Electric-Field-Responsive Handle for Large-Area Orientation of Discotic Liquid-Crystalline Molecules in Millimeter-Thick Films

2011 ◽  
Vol 123 (34) ◽  
pp. 8011-8015 ◽  
Author(s):  
Daigo Miyajima ◽  
Fumito Araoka ◽  
Hideo Takezoe ◽  
Jungeun Kim ◽  
Kenichi Kato ◽  
...  
Keyword(s):  
Electric Field ◽  
Liquid Crystalline ◽  
Thick Films ◽  
Large Area

scholarly journals Settlement process of radioactive dust to the ground inferred from the atmospheric electric field measurement

2012 ◽  
Vol 30 (1) ◽  
pp. 49-56 ◽  
Author(s):  
M. Yamauchi ◽  
M. Takeda ◽  
M. Makino ◽  
T. Owada ◽  
I. Miyagi
Keyword(s):  
Electric Field ◽  
Nuclear Power ◽  
Potential Gradient ◽  
Radioactive Material ◽  
Strong Wind ◽  
Fair Weather ◽  
Large Area ◽  
Radiation Dose Rate ◽  
Radioactive Dust ◽  
Cloudy Weather

Abstract. Radioactive materials from the accident at Fukushima Dai-ichi nuclear power plant (FNPP) in March 2011 spread over a large area, increasing the atmospheric electric conductivity by their ionizing effect, and reducing the vertical (downward) component of the DC electric field near the ground, or potential gradient (PG). PG data at Kakioka, 150 km away from the FNPP, showed independent changes compared to the radiation dose rate, and a comparison of these data revealed the local dynamics of the radioactive dust. (1) The initial drop of the PG to almost zero during 14–15 March is most likely due to radioactive dust suspended in the air near the ground during cloudy weather. (2) An episode of PG increase to more than 50 V m−1 on 16 March is most likely due to the re-suspension of the radioactive dust from the surface and subsequent removal from Kakioka by the strong wind from the non-contaminated area. (3) Low but finite values of the PG during 16–20 March most likely reflect a reduced amount of radioactive material near the ground after the above wind transported away the majority of the suspended radioactive dust. (4) Very low values of the PG after substantial rain on 20–22 March most likely reflect settlement of the radioactive material by rain-induced fallout. (5) Temporal recovery of daily variations from the end of March to the middle of April with low nighttime fair-weather baseline PG most likely reflects re-suspension of the radioactive dust into the air from the ground and trees, and subsequent transport to the other region or fallout to the ground until late April. (6) Weakening of the daily variation and gradual recovery of the nighttime fair-weather baseline after mid-April suggests a complete settlement of the radioactive material to the ground with partial migration to the subsurface.

Mechanism of Cell Lysis in Microfluidic Channel With Integrated Nanocomposite Electrodes

2013 ◽  
Author(s):  
Madhusmita Mishra ◽  
Anil Krishna Koduri ◽  
Aman Chandra ◽  
D. Roy Mahapatra ◽  
G. M. Hegde
Keyword(s):  
Electric Field ◽  
Microfluidic Channel ◽  
Cell Lysis ◽  
Bacterial Cells ◽  
Nano Composite ◽  
Time Resolved ◽  
Ac Electric Field ◽  
Cell Dispersion ◽  
Electrical Lysis ◽  
Nanocomposite Electrodes

This paper reports on the characterization of an integrated micro-fluidic platform for controlled electrical lysis of biological cells and subsequent extraction of intracellular biomolecules. The proposed methodology is capable of high throughput electrical cell lysis facilitated by nano-composite coated electrodes. The nano-composites are synthesized using Carbon Nanotube and ZnO nanorod dispersion in polymer. Bacterial cells are used to demonstrate the lysis performance of these nanocomposite electrodes. Investigation of electrical lysis in the microchannel is carried out under different parameters, one with continuous DC application and the other under DC biased AC electric field. Lysis in DC field is dependent on optimal field strength and governed by the cell type. By introducing the AC electrical field, the electrokinetics is controlled to prevent cell clogging in the micro-channel and ensure uniform cell dispersion and lysis. Lysis mechanism is analyzed with time-resolved fluorescence imaging which reveal the time scale of electrical lysis and explain the dynamic behavior of GFP-expressing E. coli cells under the electric field induced by nanocomposite electrodes. The DNA and protein samples extracted after lysis are compared with those obtained from a conventional chemical lysis method by using a UV–Visible spectroscopy and fluorimetry. The paper also focuses on the mechanistic understanding of the nano-composite coating material and the film thickness on the leakage charge densities which lead to differential lysis efficiency.

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