• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.663-664
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• 2006

In the electronic, medical, aerospace and automobile industries, many products and parts are manufactured by joining. Recently, as these get smaller, micro joining is becoming more and more important. In this study, micro wire-to-micro wire parallel joining was performed using single mode fiber laser. Maximum power of the fiber laser is 100 W. The CCD(Charge- Coupled Device, CCD) camera to observe the specimen was made up. The objective was applied to micro joining system to make a small spot size of laser beam. In order to control the target position, micro-multi-axis-stage was set up. This paper presents results for the single mode fiber laser joining of micro wires.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.3
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• pp.228-233
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• 2001

This paper presents the optimized design, fabrication and thermal characteristics of micro-heaters for thermal MEMS (micro elelctro mechanical system) applications usign SOI (Si-on-insulator) and trench structures. The micro-heater is based on a thermal measurement principle and contains for thermal isolation regions a 10㎛ thick Si membrane with oxide-filled trenches in the SOI membrane rim. The micro-heater was fabricated with Pt-RTD (resistance thermometer device) on the same substrate by suing MgO as medium layer. The thermal characteristics of the micro-heater wit the SOI membrane is 280$\^{C}$ at input power 0.9W; for the SOI membrane with 10 trenches, it is 580$\^{C}$ due to reduction of the external thermal loss. Therefore, the micro-heater with trenches in SOI membrane rim provides a powerful and versatile alternative technology for improving the performance of micro-thermal sensors and actuators.

• Laser Solutions
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• v.14 no.2
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• pp.8-12
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• 2011

As the aged population grows around the world, many medical instruments and devices have been developed recently. Among the devices, a drug delivery stent is a medical device which requires precision machining. Conventional drug delivery stent has problems of residual polymer and decoating because the drug is coated on the surface of stent with the polymer. If the drug is impregnated in micro hole array on the surface of the stent, the problem can be solved. Micro sized holes are generally fabricated by laser machining; however, the fabricated holes do not have an enough aspect ratio to contain the drug or a good surface finish to deliver it to blood vessel tissue. To overcome these problems, we propose a vibration-assisted machining mechanism with PZT (Piezoelectric Transducers) for the fabrication of micro sized holes. If the mechanism vibrates the eyepiece of the laser machining head, the laser spot on the workpiece will vibrate vertically because objective lens in the eyepiece shakes by the mechanism's vibration. According to the former researches, the vibrating frequency over 20kHz and amplitude over 500nm are preferable. The vibration mechanism has cylindrical guide, hollowed PZT and supports. In the cylinder, the eyepiece is mounted. The cylindrical guide has upper and low plates and side wall. The shape of plates and side wall are designed to have high resonating frequency and large amplitude of motion. The PZT also is selected to have high actuating force and high speed of motion. The support has symmetrical and rigid characteristics.

• Journal of Biomedical Engineering Research
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• v.43 no.4
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• pp.219-229
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• 2022

In this study, we propose a miniaturized micro-ceramic heater device. After screen-printing a silver paste between pre-sintered two aluminum oxide plates to integrate a heating circuit, the device was fabricated through a low-temperature sintering process. In order to configure the optimal heating circuit integration condition, the output current evaluation and heating test were performed according to the number of screen prints of the silver paste at various voltages. A silver paste-based heating circuit printed with a line width of 200 ㎛ and a thickness of 60 ㎛ was successfully integrated on a pre-sintered alumina substrate through a low-temperature sintering process. In the case of the 5 times printed device, the thermal response showed a response rate of 18.19 ℃/sec. To demonstrate feasibility of the proposed device in the medical field, such as bio-tissue suturing and hemostasis, a voltage was applied to pig tissue in the device to test tissue change due to heat generated from the device. These results show the possibility that the proposed small ceramic heater could be used in the medical field based on its excellent temperature response.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.10
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• pp.660-666
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• 2015

Surface acoustic wave(SAW) device is used for transporting and patterning micro-scale particles such as cells. In this research, velocity of particles was investigated moved by SAW device with two types of interdigital electrode transducers(IDTs) under various conditions. SAW devices which have single IDTs and double IDTs were designed and fabricated. On the previous studies, resultant velocities of particles were predicted considering output power and power ratio between IDTs-shape. For more accurate prediction, power loss in SAW device and a power difference between two types of IDTs-shape were considered. Maximum error between the test results and predicted values was 5 % so the power loss must be considered in the velocity prediction of the particles.

• International Journal of Precision Engineering and Manufacturing
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• v.7 no.4
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• pp.40-46
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• 2006

The market of programmable implantable pumps has bound to a monopolistic situation, inducing high device costs, thus making them inaccessible to most patients. Micro-mechanical and medical innovations allow improved performances by reducing the dimensions. This affects the consumption and weight, and, by reducing the number of parts, the cost is also affected. This paper presents the procedure followed to design an innovative implantable drug delivery system. This drug delivery system consists of a low flow pump which shall be implanted in the human body to relieve pain. In comparison to classical known solutions, this pump presents many advantages of high interest in both medical and mechanical terms. The first section of the article describes the specifications which would characterize a perfect delivery system from every points of view. This concerns shape, medication, flow, autonomy, biocompatibility, security and sterilization ability. Afterwards, an overview of existing systems is proposed in a decisional tree. Positive displacement motorized pumps are classified into three main groups: the continuous movement group, the fractioned translation group and the alternative movement group. These systems are described and the different problems which are specific to these mechanisms are presented. Since none of them fully satisfy the specifications, an innovation is justified.. The decisional tree is therefore extended by adding new principles: fractioned refilling and fractioned injection within the fractioned translation movement group, spider guiding system within the alternative translation movement group, rotational bearing guided device and notch hinge guided device in the alternative rotation movement group.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.422-423
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• 2005

RF Micro switches is a miniature device or an array of integration devices and mechanical components and fabricated with Ie batch-processing techniques. RF Micro switches application area are in phased arrays and reconfigurable apertures for defence and telecommunication systems, switching network for satellite communication, and single-pole double throw switches for wireless application. Recently, RF Micro switches have been developed for the application to the milimeter wave system. RF Micro switches offer a substantilly higher performance than PIN diode or FET switches. In this paper, SPDT(single-pole-double-throw) switch are designed to use 10 GHz. Actuation voltage and displacement are simulated by tool.

• Journal of the Korean Vacuum Society
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• v.21 no.1
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• pp.36-40
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• 2012

We have developed the detection method of the resonance frequency of micro/nano mechanical resonator using optical method. The optical interferometery method enabled us to detect the displacement change of resonators within several nm scale. The micro mechanical resonator was produced by attaching a micro mechanical cantilever to a piezo ceramic. The mass of cantilever was increased by evaporating Au using electron beam evaporator and the mass variation was estimated by detecting the resonance frequency changes.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.11
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• pp.1202-1208
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• 2009

An inverse finite element (FE) model parameter estimation algorithm can be used to characterize mechanical properties of biological tissues. Using this algorithm, we can consider the influence of material nonlinearity, contact mechanics, complex boundary conditions, and geometrical constraints in the modeling. In this study, biomechanical experiments on macro and micro samples are conducted and characterized with the developed algorithm. Macro scale experiments were performed to measure the force response of porcine livers against mechanical loadings using one-dimensional indentation device. The force response of the human liver cancer cells was also measured by the atomic force microscope (AFM). The mechanical behavior of porcine livers (macro) and human liver cancer cells (micro) were characterized with the algorithm via hyperelastic and linear viscoelastic models. The developed models are suitable for computing accurate reaction force on tools and deformation of biomechanical tissues.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.5
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• pp.674-680
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• 2017

Touch Screen Panel (TSP) is a widely used personal handheld device and as a large display apparatus. This study examines micro bump fabrication technology for TSP test process. In the testing process, as TSP is changed, should make a new micro bump for probing and modify the testing program. In this paper we use a maskless lithography system to confirm the potential to fabricatemicro bump to reducecost and manufacturing time. The requiredmaskless lithography system does not use a mask so it can reduce the cost of fabrication and it flexible to cope with changes of micro bump probing. We conducted electro field simulation by pitches of micro bump and designed the lithography pattern image for the maskless lithography process. Then we conducted Photo Resist (PR) patterning process and electro-plating process that are involved in MEMS technology to fabricate micro bump.