• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.1080-1083
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• 1997

Micro-stereolithography is a newly proposed technology as a means that can fabricate 3D micro-structures of free form. It makes a 3D structure by dividing the shape into many slices of relevant thickness along honzontal surfaces, hardening each layer of slice with a laser, and stacking them up to a des~red shape. Scale effect becomes important in this micro-fabrication process, d~fferently from the conventional stereolithography. To realize this micro-stereolithography technology, we developed an equipment using Ar+ laser, xyz stages, controllers and all the optic devices. Using the equipment, a number of micro-structures were successfully fabricated including a winecup of several tens of micrometers.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.956-959
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• 2002

In this work, a new non-lithographic micro-fabrication technique is presented. The motivation of this work is to overcome the demerits of the most commonly used photo-lithographic techniques. The micro-fabrication technique presented in this work is a two-step process which consists of mechanical scribing followed by chemical etching. This method has many advantages over other micro-fabrication techniques since it is simple, cost-effective, rapid, and flexible. Also, the technique can be used to obtain a metal structure which has sub-micrometer width patterns. In this paper, the concept of this method and its application to microsystem technology are described.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2248-2250
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• 2000

We investigated properties of PZT composite for medical ultrasonic transducer array (briefly UTA) for medicine applications fabricated by micro pressing and dicing method. Dicing method was the fabrication process of conventional ultrasonic transducer array by dicing sintered PZT sheet. Micro pressing method was the proposed process using pressing PZT green sheet by PMMA micro mold from LIGA process. Microstructures, electrical and electro -mechanical properties of fabricated UTAs of two cases were analyzed. Thickness mode electro-mechanical coupling coefficient of two cases have same values of 51%. Sintered PZT Microstructures of them showed dense and uniform. Micro pressing method was very mass productive process because of using batch type LIGA process. From results, we found micro pressing method was more competitive than dicing method for UTA fabrication. For further study, uniformity of microstructures and electro-mechanical properties of large scale, and fabrication processes of Ni plating and PMMA molding should be improved and investigated.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.181-184
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• 2002

In these day, fabrication technologies for micro parts become more important with the increase of interest on microsystem and developed through the various approaches in the whole world. Among these technologies; micro mechanical machining is one of the most effective methods for the fabrication of micro parts. In this study, we fabricated micro shafts using micro endmill and micromachining system and measured the cutting force at the process. Also, Based on the data, we simulated the deformation of micro shafts due to the cutting force. Through the simulation results, it was verified that the cutting force at the process is enough to cause dimensional error at the micro shafts.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.12
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• pp.994-1000
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• 2001

In this paper, using micro-stereolithography technology, I fabricated a liquid analyzer to measure ion concentration of a solution. Micro-stereolithography is a technology to fabricate 3-dimensional structure by applying laser beam on liquid photo-polymer. This technology makes it possible to do preassemble fabrication without any extra assembling step after the process. So, the liquid analyzer could be fabricated at very low cost with very simple process by micro-stereolithography technology. The liquid analyzer consists of a chamber for containing the solution, a pump using piezoelectric effect of PZT disk, a static mixer and a sensor for measuring ion concentration using Pt electrodes.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.05a
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• pp.237-240
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• 2004

In this study, we have developed a new $UV(\lambda=355nm)$ laser micromachining technology by direct ablation method without masks. This technology allows that 3D micro parts can be fabricated rapidly and efficiently with a low price. And it has a benefit of reducing fabricating process simply. Due to micro parts' fabrication, such technologies need the control of XYZ stages with high precision, the design of optical devices to maintain micron spot sizes of laser beam and the control technology of laser focus. Also, we have fabricated a micro-channel through the developed laser micromachining technology and verified it through the results.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.31-36
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• 2001

As a part of micro engine development feasibility estimation was done through fabrication and test of down scaled combustor and MEMS fabricated spark electrode. In an experimental observation of the down scaled combustion phenomena where flame propagation was observed by optical method and pressure change in combustor which gives the information about the reaction generated thermal energy was recorded and analyzed. Optimal combustor scale was derived to be about 2mm considering increased heat loss effect and thermal energy generation capability. Through the fabrication and discharge test of MEMS electrode effects of electrode width and gap was investigated. Electrode was fabricated by thick PR mold and electroplating. From the result discharge voltage characteristic in sub millimeter scale electrode having thickness of $40{\mu}m$ was obtained. From the result base technology for design and fabrication of micro engine was obtained.

• Applied Science and Convergence Technology
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• v.23 no.1
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• pp.54-59
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• 2014

The roll-to-roll (R2R) fabrication method to make micro-scale pillar arrays for biomimetic functionalization of surfaces is presented. Inspired by the micro-structure of plants in nature, a surface with a synthetic micro-scale pillar array is fabricated via maskless photolithography. After the surface is SAM (self-assembled monolayer) coated with trichlorosilane in a vacuum desiccator, it displays a hydrophobic property even in R2R replicas of original substrate, whose properties are further characterized using various pitches and diameters. In order to perform a comparison between the original micro-pattern and its replicas, surface morphology was analyzed using scanning electron microscopy and wetting characteristics were measured via a contact angle measurement tool with a $10{\mu}L$ water droplet. Efficient roll-to-roll imprinting for a biomimetic functionalized surface has the potential for use in many fields ranging from water repelling and self-cleaning to microfluidic chips.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.1093-1096
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• 2001

Eletrochemical phenomenon are employed in the manufacturing of micro-electrochemical machining(micro-ECM). The application of controlled electrochemical metal removal in the fabrication of microstructures and microcomponents is refer to as micro-electrochemical machining. In this paper, we introduce a new method named $\ulcorner$point-electrode electro chemical machining method$\lrcorner$ was proposed to establish micro fabrication technology by use of electrochemical machining. And we find effect of the electrochemical phenomenon in several conditions.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.5
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• pp.482-487
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• 2005