Near-field melt electrospinning of poly(ε-caprolactone) (PCL) micro-line array for cell alignment study

2018 ◽  
Vol 6 (1) ◽  
pp. 015401 ◽  
Author(s):  
Feng Liang ◽  
Han Wang ◽  
YaJu Lin ◽  
Ying Zhou ◽  
Zhifeng Wang ◽  
...  
Keyword(s):  
Near Field ◽  
Cell Alignment ◽  
Melt Electrospinning ◽  
Line Array

scholarly journals Method to Determine the Far-Field Beam Pattern of A Long Array From Subarray Beam Pattern Measurements

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1236
Author(s):  
Donghwan Jung ◽  
Jeasoo Kim
Keyword(s):  
Conventional Method ◽  
Field Condition ◽  
Near Field ◽  
Plane Waves ◽  
Measurement Data ◽  
Beam Pattern ◽  
Far Field ◽  
Water Tank ◽  
Discrete Line ◽  
Line Array

Beam pattern measurement is essential to verifying the performance of an array sonar. However, common problems in beam pattern measurement of arrays include constraints on achieving the far-field condition and reaching plane waves mainly due to limited measurement space as in acoustic water tank. For this purpose, the conventional method of measuring beam patterns in limited spaces, which transform near-field measurement data into far-field results, is used. However, the conventional method is time-consuming because of the dense spatial sampling. Hence, we devised a method to measure the beam pattern of a discrete line array in limited space based on the subarray method. In this method, a discrete line array with a measurement space that does not satisfy the far-field condition is divided into several subarrays, and the beam pattern of the line array can then be determined from the subarray measurements by the spatial convolution that is equivalent to the multiplication of beam pattern. The proposed method was verified through simulation and experimental measurement on a line array with 256 elements of 16 subarrays.

Fabrication of bioinspired grid-crimp micropatterns by melt electrospinning writing for bone-ligament interface study

2022 ◽  
Author(s):  
Junjie Xiong ◽  
Han Wang ◽  
Xingzi Lan ◽  
Yaqi Wang ◽  
Zixu Wang ◽  
...  
Keyword(s):  
Structural Parameters ◽  
Processing Parameters ◽  
Cell Alignment ◽  
Native Structure ◽  
3D Scaffold ◽  
Native Bone ◽  
Melt Electrospinning ◽  
Fiber Spacing ◽  
Interface Study ◽  
Different Levels

Abstract Many strategies have been adopted to engineer bone-ligament interface, which is of great value to both the tissue regeneration and the mechanism understanding underlying interface regeneration. However, how to recapitulate the complexity and heterogeneity of the native bone-ligament interface including the structural, cellular and mechanical gradients is still challenging. In this work, a bioinspired grid-crimp micropattern fabricated by melt electrospinning writing (MEW) was proposed to mimic the native structure of bone-ligament interface. The printing strategy of crimped fiber micropattern was developed and the processing parameters were optimized, which were used to mimic the crimp structure of the collagen fibrils in ligament. The guidance effect of the crimp angle and fiber spacing on the orientation of fibroblasts was studied, and both of them showed different levels of cell alignment effect.. MEW grid micropatterns with different fiber spacings were fabricated as bone region. Both the alkaling phosphatase activity and calcium mineralization results demonstrated the higher osteoinductive ability of the MEW grid structures, especially for that with smaller fiber spacing. The combined grid-crimp micropatterns were applied for the co-culture of fibroblasts and osteoblasts. The results showed that more cells were observed to migrate into the in-between interface region for the pattern with smaller fiber spacing, suggested the faster migration speed of cells. Finally, a cylindrical triphasic scaffold was successfully generated by rolling the grid-crimp micropatterns up, showing both structural and mechanical similarity to the native bone-ligament interface. In summary, the proposed strategy is reliable to fabricate grid-crimp triphasic micropatterns with controllable structural parameters to mimic the native bone-to-ligament structure, and the generated 3D scaffold shows great potential for the further bone-ligament interface tissue engineering.

Study of Microscale Three-Dimensional Printing Using Near-Field Melt Electrospinning

2017 ◽  
Author(s):  
Xiangyu You ◽  
Chengcong Ye ◽  
Ping Guo
Keyword(s):  
High Resolution ◽  
3D Printing ◽  
Low Cost ◽  
Near Field ◽  
Three Dimensional ◽  
Thin Wall ◽  
Direct Writing ◽  
Melt Electrospinning ◽  
Wall Structures ◽  
Jet Trajectory

Three-dimensional (3D) printing of microscale structures with high resolution (sub-micron) and low cost is still a challenging work for the existing 3D printing techniques. Here we report a direct writing process via near-field melt electrospinning to achieve microscale printing of single filament wall structures. The process allows continuous direct writing due to the linear and stable jet trajectory in the electric near-field. The layer-by-later stacking of fibers, or self-assembly effect, is attributed to the attraction force from the molten deposited fibers and accumulated negative charges. We demonstrated successful printing of various 3D thin wall structures (freestanding single walls, double walls, annular walls, star-shaped structures, and curved wall structures) with a minimal wall thickness less than 5 μm. By optimizing the process parameters of near-field melt electrospinning (electric field strength, collector moving speed, and needle-to-collector distance), ultrafine poly (ε-caprolactone) (PCL) fibers have been stably generated and precisely stacked and fused into 3D thin-wall structures with an aspect ratio of more than 60. It is envisioned that the near-field melt electrospinning can be transformed into a viable high-resolution and low-cost microscale 3D printing technology.

Study of Microscale Three-Dimensional Printing Using Near-Field Melt Electrospinning

2017 ◽  
Vol 5 (4) ◽  
Author(s):  
Xiangyu You ◽  
Chengcong Ye ◽  
Ping Guo
Keyword(s):  
High Resolution ◽  
3D Printing ◽  
Low Cost ◽  
Near Field ◽  
Three Dimensional ◽  
Thin Wall ◽  
Direct Writing ◽  
Melt Electrospinning ◽  
Wall Structures ◽  
Jet Trajectory

Three-dimensional (3D) printing of microscale structures with high-resolution (submicron) and low-cost is still a challenging work for the existing 3D printing techniques. Here, we report a direct writing process via near-field melt electrospinning (NFME) to achieve microscale printing of single filament wall structures. The process allows continuous direct writing due to the linear and stable jet trajectory in the electric near field. The layer-by-layer stacking of fibers, or self-assembly effect, is attributed to the attraction force from the molten deposited fibers and accumulated negative charges. We demonstrated successful printing of various 3D thin-wall structures with a minimal wall thickness less than 5 μm. By optimizing the process parameters of NFME, ultrafine poly (ε-caprolactone) (PCL) fibers have been stably generated and precisely stacked and fused into 3D thin-wall structures with an aspect ratio of more than 60. It is envisioned that the NFME can be transformed into a viable high-resolution and low-cost microscale 3D printing technology.

Fabrication of Micro Fluidic Channels in Polymers by Melt-Electrospinning

2017 ◽  
Vol 909 ◽  
pp. 151-156
Author(s):  
Jun Zeng ◽  
Can Ran Lin ◽  
Fei Yu Fang ◽  
Feng Liang ◽  
Han Wang ◽  
...  
Keyword(s):  
White Light ◽  
Near Field ◽  
Microfluidic Channels ◽  
Direct Write ◽  
White Light Interferometer ◽  
Melt Electrospinning ◽  
Micro Channels

The microfluidic has been applied to the field of bio-medicine, micro fluidic electronic in recent years. In this paper we reported a simple methodology to fabricate PDMS microfluidic channels. The method consists of three main fabrication steps: (1) Direct write the micrometric PCL 2D or 3D pattern by the near-field melt-electrospinning. (2) Cast the PDMS on the printed PCL pattern. (3) Completely remove the embedded sacrificial PCL layer by soaking and flushing with acetone. Uniformity of the morphology of the micro channels and well-alignment could be easily achieved due to include the dimensions achievable using this method. We have also designed and fabricated a few micro fluidic channels. SEM and white-light interferometer images were taken to illustrate the characters of essential parts. This work demonstrated the potential utilization of this technique.

Direct write micro/nano optical fibers by near-field melt electrospinning

2017 ◽  
Vol 42 (24) ◽  
pp. 5106 ◽  
Author(s):  
Qinnan Chen ◽  
Xuecui Mei ◽  
Zhe Shen ◽  
Dezhi Wu ◽  
Yang Zhao ◽  
...  
Keyword(s):  
Optical Fibers ◽  
Near Field ◽  
Direct Write ◽  
Melt Electrospinning

Near-field scanning optical microscopy

1986 ◽  
Vol 44 ◽  
pp. 642-643
Author(s):  
E. Betzig ◽  
A. Harootunian ◽  
M. Isaacson ◽  
A. Lewis
Keyword(s):  
Near Field ◽  
Optical Microscope ◽  
Visible Radiation ◽  
Field Methods ◽  
Optical Elements ◽  
Optical Region ◽  
Order Of Magnitude ◽  
Nondestructive Imaging ◽  
Scanning Optical Microscopy ◽  
Near Field Scanning

In general, conventional methods of optical imaging are limited in spatial resolution by either the wavelength of the radiation used or by the aberrations of the optical elements. This is true whether one uses a scanning probe or a fixed beam method. The reason for the wavelength limit of resolution is due to the far field methods of producing or detecting the radiation. If one resorts to restricting our probes to the near field optical region, then the possibility exists of obtaining spatial resolutions more than an order of magnitude smaller than the optical wavelength of the radiation used. In this paper, we will describe the principles underlying such "near field" imaging and present some preliminary results from a near field scanning optical microscope (NS0M) that uses visible radiation and is capable of resolutions comparable to an SEM. The advantage of such a technique is the possibility of completely nondestructive imaging in air at spatial resolutions of about 50nm.

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