Generation of high aspect ratio complex micro-features by micro-electrochemical milling employing novel flushing technique

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.

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

Volume 7: 5th International Conference on Micro- and Nanosystems; 8th International Conference on Design and Design Education; 21st Reliability, Stress Analysis, and Failure Prevention Conference ◽

10.1115/detc2011-48331 ◽

2011 ◽

Cited By ~ 3

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.

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

Micromachines ◽

10.3390/mi9020058 ◽

2018 ◽

Vol 9 (2) ◽

pp. 58 ◽

Cited By ~ 3

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

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Laser Drilling on Elastomeric Polymers

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.591-593.307 ◽

2012 ◽

Vol 591-593 ◽

pp. 307-310

Author(s):

Chun Lei Kang ◽

Yan Xu ◽

Kai Leung Yung ◽

Wei Chen ◽

Hang Liu

Keyword(s):

Aspect Ratio ◽

High Aspect Ratio ◽

Soft Lithography ◽

Average Power ◽

Pulsed Laser ◽

Laser Drilling ◽

Fabrication Method ◽

Drilling Technology ◽

Micro Features ◽

Micro Structures

Elastomeric polymers have been used as moulds for fabricating micro structures in the soft lithography technology due to their elastic features and unstickiness to polymer features. Previously, the micro moulds were normally produced by imprinting on micro prototypes, which are fabricated using deep reactive etching or photolithography. In this paper, we introduce a direct mould fabrication method, which uses pulsed laser drilling technology to directly generate high aspect ratio patterns in elastomeric polymers. The effects of laser parameters such as pulse repetition rate and average power on the drilling qualities are systematically studied. The techniques presented in this paper would provide a more flexible way to fabricate high aspect ratio micro features on elastomer mould efficiently.

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A Newtonian approach to predict the parameters required to machine high aspect ratio channels of prescribed topography

10.32920/ryerson.14661939 ◽

2021 ◽

Author(s):

Aria Ghazavi

Keyword(s):

Aspect Ratio ◽

Borosilicate Glass ◽

High Aspect Ratio ◽

Traverse Speed ◽

Cross Sectional ◽

Average Accuracy ◽

Micro Channels ◽

Micro Features ◽

Micro Machine ◽

Sectional Shape

Control of the microchannels’ cross-sectional shape may be of interest in micro-heat sinks, microfluidic particle sorting, and micro-machine lubrication applications. Previously, inverse methods have been used to determine the abrasive jet micromachining (AJM) traverse speed and path required to sculpt the desired cross-section for low Aspect Ratio (AR, the ratio of depth to width, see page xiv) topographies (<0.06). This thesisintroduces an iterative inverse method which allows prediction of the machining procedure required to sculpt high AR (>0.06-1) microchannels of prescribed cross-sectional shape using mask-less AJM. The predictions were experimentally verified for trapezoidal and semi-circular micro-channels and protruded features in borosilicate glass, and symmetric and non-symmetric wedges in poly-methyl-methacrylate (PMMA). Overall, the average accuracy of the machined profiles was 93.6 % in borosilicate glass and 91 % in PMMA. The methodology opens up new possibilities for the micro-fabrication of high-aspect-ratio micro-features of virtually any desired shape.

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