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.

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.

Sinusoidal AC-induced electrohydrodynamic direct-writing nanofibers on insulating collector

2021 ◽  
pp. 2140009
Author(s):  
Huatan Chen ◽  
Guoyi Kang ◽  
Jiaxin Jiang ◽  
Juan Liu ◽  
Xiang Wang ◽  
...  
Keyword(s):  
Electric Field ◽  
Flexible Electronics ◽  
Direct Writing ◽  
Printing Process ◽  
Ac Electric Field ◽  
Jet Printing ◽  
Voltage Frequency ◽  
Fiber Deposition ◽  
The Stability ◽  
Application Fields

Printing orderly patterns on the insulating collector is the key for the development and application of flexible electronics. However, electrospinning on the insulating collector still has the problem of unstable jet due to the charge accumulation. The alternating current (AC)-induced electrohydrodynamic direct-writing (EDW) technology is a good way to decrease the interferences of charge repulsion, which is beneficial to printing orderly micro/nanostructures on the insulating collector. In this work, the sinusoidal AC-induced EDW is used to enhance the stability of charged jet and the deposition behaviors under AC electric field are also studied. The reciprocation transferring of charges induced by the AC electric field decreased the density of the accumulating charges on the insulating collector. The effect of AC electric field parameters on the direct-written micro/nanostructures are investigated to optimize the printing process. As the voltage peak increases, the fiber deposition bandwidth shows a trend of decreasing first and then increasing. Increasing the voltage frequency appropriately is beneficial to decrease the bandwidth of fiber deposition and to increase the stability of the jet. By improving the stability and controllability of the jet printing process, precise micro/nanopatterns can be direct-written on the insulating collector. This research provides a good foundation for expanding the application fields of EDW.

Bi4Ti3O12 Particles Size Influence on Electrorheolocical Response

2012 ◽  
Vol 727-728 ◽  
pp. 1462-1466 ◽  
Author(s):  
Glauber Márcio da Silva Luz ◽  
Maria Virginia Gelfuso ◽  
Daniel Thomazini ◽  
Pedro Perri Pinto ◽  
Antônio José Faria Bombard
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Stress Transfer ◽  
Solid State Reaction Method ◽  
Milling Process ◽  
Real Time Control ◽  
Conventional Solid State Reaction ◽  
Time Control ◽  
Typical Morphology ◽  
High Dielectric

Electrorheological uids (ER) are commonly known as suspensions composed of semiconducting particles dispersed in insulating oil that respond to electric fields by gelling. The increase in suspension viscosity on application of the field is typically rapid and reversible and as a result, the ER response is amenable to applications where real time control of stress transfer properties is required. Ferroelectric particles are interesting in this application due to the presence of spontaneous polarization and high dielectric constant. Particularly, Bismuth Titanate (Bi4Ti3O12 - BIT) is well-known as layer-structured ferroelectrics, so the typical morphology of these crystals is lamellar. Therefore, these particles dispersed in oil, in the presence of an electric field must produce an interesting ER response. Thus, BIT powders were prepared by the conventional solid state reaction method and the particles size was adjusted using ball milling process. Different ER fluids containing average particles size about 2.5 to 0.5 μm were dispersed in silicon oil about 10% vol and were submitted to AC and DC electric field. The relation between the BIT particles size with the ER response was observed, presenting an increase of the shear stress with the reduction on particle size.

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 Optical Anapole Modes in Gallium Phosphide Nanodisk with Forked Slits for Electric Field Enhancement

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1490
Author(s):  
Jingwei Lv ◽  
He Zhang ◽  
Chao Liu ◽  
Zao Yi ◽  
Famei Wang ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Hot Spots ◽  
Gallium Phosphide ◽  
Physical Phenomenon ◽  
Near Field ◽  
Field Enhancement ◽  
High Refractive Index ◽  
Novel Approach ◽  
New Frontier

High refractive index dielectric nanostructures represent a new frontier in nanophotonics, and the unique semiconductor characteristics of dielectric systems make it possible to enhance electric fields by exploiting this fundamental physical phenomenon. In this work, the scattered radiation spectral features and field-enhanced interactions of gallium phosphide disks with forked slits at anapole modes are investigated systematically by numerical and multipole decomposition analyses. Additional enhancement of the electric field is achieved by opening the forked slits to create high-intensity hot spots inside the disk, and nearby molecules can access these hot spots directly. The results reveal a novel approach for near-field engineering such as electric field localization, nonlinear optics, and optical detection.

SIMULATION OF THE FLIGHT OF A DROP OF GALVANIC ELECTROLYTE IN AN INHOMOGENEOUS FIELD OF AN ELECTRIC CATCHER

2020 ◽  
Author(s):  
V.I. Garshin ◽  
◽  
A.R. Lebedev ◽  
S.E. Geraskova ◽  
◽  
...  
Keyword(s):  
Electric Field ◽  
Flight Path ◽  
Inhomogeneous Field ◽  
Inhomogeneous Electric Field ◽  
Trajectory Method

The article shows the relations for modeling an inhomogeneous electric field and the flight path of a drop of galvanic electrolyte in it. Estimates are preliminary. Articles and patents of authors in which non-uniform fields are already used are given. A modified trajectory method is proposed for evaluating the effectiveness of trapping harmful electrolyte droplets.

Tuning the Electric Field Response of MOFs by Rotatable Dipolar Linkers

2019 ◽  
Author(s):  
Johannes P. Dürholt ◽  
Babak Farhadi Jahromi ◽  
Rochus Schmid
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Structural Changes ◽  
Dielectric Behavior ◽  
Two Dimensions ◽  
Dielectric Constants ◽  
Electric Response ◽  
Dipole Strength ◽  
Metal Organic ◽  
Dynamics Simulations

Recently the possibility of using electric fields as a further stimulus to trigger structural changes in metal-organic frameworks (MOFs) has been investigated. In general, rotatable groups or other types of mechanical motion can be driven by electric fields. In this study we demonstrate how the electric response of MOFs can be tuned by adding rotatable dipolar linkers, generating a material that exhibits paralectric behavior in two dimensions and dielectric behavior in one dimension. The suitability of four different methods to compute the relative permittivity κ by means of molecular dynamics simulations was validated. The dependency of the permittivity on temperature T and dipole strength μ was determined. It was found that the herein investigated systems exhibit a high degree of tunability and substantially larger dielectric constants as expected for MOFs in general. The temperature dependency of κ obeys the Curie-Weiss law. In addition, the influence of dipolar linkers on the electric field induced breathing behavior was investigated. With increasing dipole moment, lower field strength are required to trigger the contraction. These investigations set the stage for an application of such systems as dielectric sensors, order-disorder ferroelectrics or any scenario where movable dipolar fragments respond to external electric fields.

scholarly journals Meta-Deflectors Made of Dielectric Nanohole Arrays with Anti-Damage Potential

Photonics ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 107
Author(s):  
Haichao Yu ◽  
Feng Tang ◽  
Jingjun Wu ◽  
Zao Yi ◽  
Xin Ye ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Laser Cutting ◽  
High Complexity ◽  
Damage Potential ◽  
Optical Components ◽  
Nanohole Arrays ◽  
Intense Light ◽  
Polarization Of Light ◽  
Air Hole

In intense-light systems, the traditional discrete optical components lead to high complexity and high cost. Metasurfaces, which have received increasing attention due to the ability to locally manipulate the amplitude, phase, and polarization of light, are promising for addressing this issue. In the study, a metasurface-based reflective deflector is investigated which is composed of silicon nanohole arrays that confine the strongest electric field in the air zone. Subsequently, the in-air electric field does not interact with the silicon material directly, attenuating the optothermal effect that causes laser damage. The highest reflectance of nanoholes can be above 99% while the strongest electric fields are tuned into the air zone. One presentative deflector is designed based on these nanoholes with in-air-hole field confinement and anti-damage potential. The 1st order of the meta-deflector has the highest reflectance of 55.74%, and the reflectance sum of all the orders of the meta-deflector is 92.38%. The optothermal simulations show that the meta-deflector can theoretically handle a maximum laser density of 0.24 W/µm2. The study provides an approach to improving the anti-damage property of the reflective phase-control metasurfaces for intense-light systems, which can be exploited in many applications, such as laser scalpels, laser cutting devices, etc.

scholarly journals Integrating flexible electronics for pulsed electric field delivery in a vascularized 3D glioblastoma model

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Marie C. Lefevre ◽  
Gerwin Dijk ◽  
Attila Kaszas ◽  
Martin Baca ◽  
David Moreau ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Flexible Electronics ◽  
Soft Tissues ◽  
Multiphoton Microscopy ◽  
Membrane Integrity ◽  
Tumor Model ◽  
Pulsed Electric Fields ◽  
In Ovo ◽  
Cell Membrane Integrity

AbstractGlioblastoma is a highly aggressive brain tumor, very invasive and thus difficult to eradicate with standard oncology therapies. Bioelectric treatments based on pulsed electric fields have proven to be a successful method to treat cancerous tissues. However, they rely on stiff electrodes, which cause acute and chronic injuries, especially in soft tissues like the brain. Here we demonstrate the feasibility of delivering pulsed electric fields with flexible electronics using an in ovo vascularized tumor model. We show with fluorescence widefield and multiphoton microscopy that pulsed electric fields induce vasoconstriction of blood vessels and evoke calcium signals in vascularized glioblastoma spheroids stably expressing a genetically encoded fluorescence reporter. Simulations of the electric field delivery are compared with the measured influence of electric field effects on cell membrane integrity in exposed tumor cells. Our results confirm the feasibility of flexible electronics as a means of delivering intense pulsed electric fields to tumors in an intravital 3D vascularized model of human glioblastoma.

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