scholarly journals Effect of Process Parameters on Flow Length and Flash Formation in Injection Moulding of High Aspect Ratio Polymeric Micro Features

Micromachines ◽  
2018 ◽  
Vol 9 (2) ◽  
pp. 58 ◽  
Author(s):  
Abdelkhalik Eladl ◽  
Rania Mostafa ◽  
Aminul Islam ◽  
Dario Loaldi ◽  
Hassan Soltan ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Process Parameters ◽  
High Aspect Ratio ◽  
Injection Moulding ◽  
Flow Length ◽  
Micro Features

A multi-scale E-Jet 3D printing regulated by structured multi-physics field

2021 ◽  
Author(s):  
Kai Li ◽  
Yihui Zhao ◽  
Maiqi Liu ◽  
Xiaoying Wang ◽  
Fangyuan Zhang ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
3D Printing ◽  
Aspect Ratio ◽  
Process Parameters ◽  
High Aspect Ratio ◽  
Thermal Field ◽  
Structural Features ◽  
Microfluidic Chips ◽  
Multi Scale ◽  
Fluid Field

Abstract Micro/nano scale structure as important functional part have been widely used in wearable flexible sensors, gas sensors, biological tissue engineering, microfluidic chips super capacitors and so on. Here a multi-scale electrohydrodynamic jet (E-Jet) 3D printing approach regulated by structured multi-physics fields was demonstrated to generate 800 nm scale 2D geometries and high aspect ratio 3D structures. The simulation model of jetting process under resultant effect of top fluid field, middle electric field and bottom thermal field was established. And the physical mechanism and scale law of jet formation were studied. The effects of thermal field temperature, applied voltage and flow rate on the jet behaviors were studied; and the range of process parameters of stable jet was obtained. The regulation of printing parameters was used to manufacture the high resolution gradient graphics and the high aspect ratio structure with tight interlayer bonding. The structural features could be flexibly adjusted by reasonably matching the process parameters. Finally, PCL/PVP composite scaffolds with cell-scale fiber and ordered fiber spacing were printed. The proposed E-Jet printing method provides an alternative approach for the application of biopolymer materials in tissue engineering.

SYNCHROTRON-RADIATION-SUPPORTED HIGH-ASPECT-RATIO NANOFABRICATION

COSMOS ◽  
2007 ◽  
Vol 03 (01) ◽  
pp. 79-88
Author(s):  
A. CHEN ◽  
G. LIU ◽  
L. K. JIAN ◽  
HERBERT O. MOSER
Keyword(s):  
Synchrotron Radiation ◽  
Aspect Ratio ◽  
Light Source ◽  
Process Parameters ◽  
High Aspect Ratio ◽  
Radiation Spectrum ◽  
Nanometer Scale ◽  
X Ray ◽  
Preliminary Results ◽  
Synchrotron Light

X-ray lithography with synchrotron radiation is an important nanolithographic tool which has unique advantages in the production of high aspect ratio nanostructures. The optimum synchrotron radiation spectrum for nanometer scale X-ray lithography is normally in the range of 500 eV to 2 keV. In this paper, we present the main methods, equipment, process parameters and preliminary results of nanofabrication by proximity X-ray lithography within the nanomanufacturing program pursued by Singapore Synchrotron Light Source (SSLS). Nanostructures with feature sizes down to 200 nm and an aspect ratio up to 10 have been successfully achieved by this approach.

scholarly journals Injection moulding of ultra high aspect ratio nanostructures using coated polymer tooling

2014 ◽  
Vol 24 (7) ◽  
pp. 075019 ◽  
Author(s):  
J M Stormonth-Darling ◽  
R H Pedersen ◽  
C How ◽  
N Gadegaard
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Injection Moulding

Active Scalable Elastomer Mold to Ease Demolding of High Aspect Ratio Micro Features

2012 ◽  
Vol 591-593 ◽  
pp. 880-883
Author(s):  
Yan Xu ◽  
Kai Leung Yung ◽  
Hang Liu
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Experimental Results ◽  
Metal Mold ◽  
Micro Features ◽  
New System

To fabricate high aspect ratio micro/nano features, demolding is more challenging than filling of melt into micro mold as solidified micro features can be easily peeled off when demolding resistance is high. Besides using anti-stick agent, using deformable mold is a new solution proposed by the authors. This paper presents a setup for testing the deformable active mold. Experimental results on micro thermal molding with the developed mold deforming system prove that the new system can successfully demold high aspect ratio micro features that can not be produced with traditional metal mold.

Micro Electro Discharge Milling of Freeform Micro-Features With High Aspect Ratio

2011 ◽  
Author(s):  
F. Modica ◽  
V. Marrocco ◽  
G. Trotta ◽  
I. Fassi
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Fill Factor ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
High Surface ◽  
Adjustment Factor ◽  
Machining Performance ◽  
Technological Parameters ◽  
Micro Features

Micro Electrical Discharge Machining (μEDM) technology is widely used to process conductive materials, regardless to their hardness and strength, and realize micro-sized feature components for industrial application. μEDM proves to be a very competitive fabrication technology since micro-sized features within 1 μm of accuracy and with high surface quality (<0.1 μm Ra) can be attained. When High Aspect Ratio (HAR) micro-features are machined via μEDM milling, the main problem is to identify the technological parameters and settings mainly affecting the process performance. In the present study the influence of the adjustment factor and flushing conditions are investigated and discussed for the machining of HAR cavities with different Fill Factor (FF). Material Removal Rate (MRR) and Tool Wear Ratio (TWR) are evaluated when deep cavities having variable square sections are machined on Ni-Cr-Mo steel workpiece. All tests are performed using a state of the art micro-EDM milling machine, with a Tungsten Carbide electrode tool and a dielectric oil for flushing. The experimental results presented here highlight different trends in the machining performance in dependence of AR and FF. In particular, MRR exhibits a decreasing trend where the curve slopes are strictly related to the FF and the initial adjustment factor. On the contrary, TWR, for higher FF, displays two distinct trends characterized by opposite slopes in each curve. Finally a nozzle for micro-injection with varying Aspect Ratio and Fill Factor is machined and presented as demonstrator.

Post Titanium Silicide Processing

1995 ◽  
Vol 402 ◽  
Author(s):  
G. Grynkewich ◽  
V. Ilderem ◽  
M. Miller ◽  
S. Ramaswami
Keyword(s):  
Aspect Ratio ◽  
Contact Resistance ◽  
Process Parameters ◽  
High Aspect Ratio ◽  
Film Formation ◽  
Titanium Silicide ◽  
Fluorocarbon Polymer ◽  
Sidewall Angle ◽  
The Impact ◽  
Etch Profile

AbstractDecreasing contact dimensions coupled with the need for planarization to accommodate multiple layers of metal have created many challenges for the contact etch module. For example, contact etch processes are often required to stop on thin titanium silicide while at the same time forming high aspect ratio, straightwalled contacts. In this paper, the impact of various dielectric compositions and contact etch process parameters on etch profile, selectivity, and contact resistance is presented for the formation of high aspect ratio, submicron contacts to thin TiSi2 layers. The etch profile is formed by RIE using a mixture of CHF3 and various amounts of CF4. Surprisingly, the sidewall angle and selectivity to silicide showed little dependence on the percent CF4. Contact resistance measurements, however, varied greatly with percent CF4 and contact aspect ratio. The variation of contact resistance with etch chemistry was attributed to a variation in the extent of fluorocarbon polymer film formation, which in turn depends on the ratio of carbon to fluorine in the plasma. Finally, post contact etch treatments were examined for efficiency in removing the polymer films from the high aspect ratio contacts.

Sign in / Sign up

Export Citation Format

Share Document