The Experts below are selected from a list of 1554 Experts worldwide ranked by ideXlab platform
Sunghoon Kwon - One of the best experts on this subject based on the ideXlab platform.
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Optofluidic in situ Maskless Lithography of charge selective nanoporous hydrogel for DNA preconcentration
Biomicrofluidics, 2010Co-Authors: Hyoki Kim, Junhoi Kim, Eun-geun Kim, Austen James Heinz, Sunghoon Kwon, Honggu ChunAbstract:An optofluidic Maskless photopolymerization process was developed for in situ negatively charged nanoporous hydrogel poly-AMPS (2-acrylamido-2-methyl-1-propanesulfonic acid) fabrication. The optofluidic Maskless Lithography system, which combines a high power UV source and digital mirror device, enables fast polymerization of arbitrary shaped hydrogels in a microfluidic device. The poly-AMPS hydrogel structures were positioned near the intersections of two microchannels, and were used as a cation-selective filter for biological sample preconcentration. Preconcentration dynamics as well as the fabricated polymer shape were analyzed in three-dimensions using fluorescein sample and a confocal microscope. Finally, single-stranded DNA preconcentration was demonstrated for polymerase chain reaction-free signal enhancement.
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Ordered fluidic self-assembly of 3D microparticles based on gray-scale optofluidic Maskless Lithography
Conference on Lasers and Electro-Optics 2010, 2010Co-Authors: Sung-eun Choi, Wook Park, Hosuk Lee, Sunghoon KwonAbstract:We demonstrate ordered fluidic self-assembly of lithographically fabricated microparticles in microfluidic channels. Unique 3D shapes of the microparticles are fabricated by gray-scale optofluidic Maskless Lithography. We show these structures enhance orderness of the monolayer crystal.
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Optofluidic encapsulation and manipulation of silicon microchips using image processing based optofluidic Maskless Lithography and railed microfluidics
Lab on a chip, 2009Co-Authors: Su Eun Chung, Seung Ah Lee, Jiyun Kim, Sunghoon KwonAbstract:We demonstrate optofluidic encapsulation of silicon microchips using image processing based optofluidic Maskless Lithography and manipulation using railed microfluidics. Optofluidic Maskless Lithography is a dynamic photopolymerization technique of free-floating microstructures within a fluidic channel using spatial light modulator. Using optofluidic Maskless Lithographyvia computer-vision aided image processing, polymer encapsulants are fabricated for chip protection and guiding-fins for efficient chip conveying within a fluidic channel. Encapsulated silicon chips with guiding-fins are assembled using railed microfluidics, which is an efficient guiding and heterogeneous self-assembly system of microcomponents. With our technology, externally fabricated silicon microchips are encapsulated, fluidically guided and self-assembled potentially enabling low cost fluidic manipulation and assembly of integrated circuits.
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optofluidic Maskless Lithography system for real time synthesis of photopolymerized microstructures in microfluidic channels
Applied Physics Letters, 2007Co-Authors: Su Eun Chung, Hyunsung Park, Kyoungsik Yu, Wook Park, Namkyoo Park, Sunghoon KwonAbstract:The authors propose an optofluidic Maskless Lithography technique that can dynamically synthesize free-floating polymeric microstructures inside microfluidic channels by selectively polymerizing photocurable resin with high-speed two-dimensional spatial light modulators. The combination of programable optical projection and microfluidic devices allows one to precisely control the timing and location of the photopolymerization process for microstructure fabrication. Real-time generation of microparticles with various shapes, sizes, ordering, and material contents are experimentally demonstrated. Long polymeric structures of which size is not limited by the exposure field of view can also be fabricated.
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In-Situ Fabrication of Polymeric Microstructures in Microfluidic Channels using Optofluidic Maskless Lithography
2007Co-Authors: Su Eun Chung, Hyunsung Park, Kyoungsik Yu, Wook Park, Sunghoon KwonAbstract:We demonstrate an optofluidic Maskless Lithography (OFML) technique to fabricate various free floating polymer microstructures in microfluidic channels. Combining Maskless Lithography and microfluidics, we present temporal and spatial control of polymeric microstructure generation in microfluidic channels. Shape and size of the polymeric structures are easily defined by computer generated mask pattern on a MEMS spatial light modulator. Taking advantage of the fluidic motion, high aspect ratio structures bigger than exposure field of view have been fabricated.
Su Eun Chung - One of the best experts on this subject based on the ideXlab platform.
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Optofluidic encapsulation and manipulation of silicon microchips using image processing based optofluidic Maskless Lithography and railed microfluidics
Lab on a chip, 2009Co-Authors: Su Eun Chung, Seung Ah Lee, Jiyun Kim, Sunghoon KwonAbstract:We demonstrate optofluidic encapsulation of silicon microchips using image processing based optofluidic Maskless Lithography and manipulation using railed microfluidics. Optofluidic Maskless Lithography is a dynamic photopolymerization technique of free-floating microstructures within a fluidic channel using spatial light modulator. Using optofluidic Maskless Lithographyvia computer-vision aided image processing, polymer encapsulants are fabricated for chip protection and guiding-fins for efficient chip conveying within a fluidic channel. Encapsulated silicon chips with guiding-fins are assembled using railed microfluidics, which is an efficient guiding and heterogeneous self-assembly system of microcomponents. With our technology, externally fabricated silicon microchips are encapsulated, fluidically guided and self-assembled potentially enabling low cost fluidic manipulation and assembly of integrated circuits.
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optofluidic Maskless Lithography system for real time synthesis of photopolymerized microstructures in microfluidic channels
Applied Physics Letters, 2007Co-Authors: Su Eun Chung, Hyunsung Park, Kyoungsik Yu, Wook Park, Namkyoo Park, Sunghoon KwonAbstract:The authors propose an optofluidic Maskless Lithography technique that can dynamically synthesize free-floating polymeric microstructures inside microfluidic channels by selectively polymerizing photocurable resin with high-speed two-dimensional spatial light modulators. The combination of programable optical projection and microfluidic devices allows one to precisely control the timing and location of the photopolymerization process for microstructure fabrication. Real-time generation of microparticles with various shapes, sizes, ordering, and material contents are experimentally demonstrated. Long polymeric structures of which size is not limited by the exposure field of view can also be fabricated.
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In-Situ Fabrication of Polymeric Microstructures in Microfluidic Channels using Optofluidic Maskless Lithography
2007Co-Authors: Su Eun Chung, Hyunsung Park, Kyoungsik Yu, Wook Park, Sunghoon KwonAbstract:We demonstrate an optofluidic Maskless Lithography (OFML) technique to fabricate various free floating polymer microstructures in microfluidic channels. Combining Maskless Lithography and microfluidics, we present temporal and spatial control of polymeric microstructure generation in microfluidic channels. Shape and size of the polymeric structures are easily defined by computer generated mask pattern on a MEMS spatial light modulator. Taking advantage of the fluidic motion, high aspect ratio structures bigger than exposure field of view have been fabricated.
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Optofluidic Maskless Lithography System
TRANSDUCERS 2007 - 2007 International Solid-State Sensors Actuators and Microsystems Conference, 2007Co-Authors: Su Eun Chung, Hyunsung Park, Wook Park, Namkyoo Park, Sunghoon KwonAbstract:We propose and demonstrate an optofluidic Maskless Lithography technique to fabricate various polymer microparticles and microwires in microfluidic channels. Combining Maskless Lithography and microfluidic systems, we demonstrate temporal and spatial control of polymeric micro structure generation in microfluidic channels.
Yung-chun Lee - One of the best experts on this subject based on the ideXlab platform.
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Maskless Lithography based on oblique scanning of point array with digital distortion correction
Optics and Lasers in Engineering, 2021Co-Authors: Hung Laing Chien, Yi Hsien Chiu, Yung-chun LeeAbstract:Abstract The oblique scanning of a rectangular array of ultraviolet (UV) spots provides a feasible means of realizing Maskless Lithography with well-controlled UV exposure. In such a method, the UV light is modulated by a digital micromirror device (DMD), collected by a microlens/pinhole array, and then projected onto a photoresist (PR) layer for UV patterning. However, the strict requirements imposed on the optical distortion of the image projection system pose a significant technical challenge. Accordingly, the present study proposes a method for improving the UV patterning accuracy by using an empirically-derived distortion model to adjust the working DMD images. The patterning errors caused by optical distortion are then further reduced by adjusting the tilt angle of the oblique scanning process. The experimental results show that the proposed method yields a significant reduction in the UV patterning error. Consequently, it provides a practical solution for performing Maskless Lithography without the need for a high-quality image projection lens system.
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Maskless Lithography based on digital micromirror device dmd and double sided microlens and spatial filter array
Optics and Laser Technology, 2019Co-Authors: Duc-hanh Dinh, Hung-liang Chien, Yung-chun LeeAbstract:Abstract A new type of Maskless Lithography system based on digital mirror device (DMD) is proposed, constructed, and experimentally demonstrated. It includes a pin-hole array sandwiched by two microlens arrays on each side, known as double-sided microlens/spatial-filter array (D-MSFA), and aligned with a DMD. Ultraviolet (UV) light reflected by DMD is first collected by the first microlens array, filtered through the pin-hole array, and then re-focused by the second microlens array into a UV spot array. Along with an obliquely scanning method, this D-MSFA/DMD-based Maskless Lithography system can perform not only 2D but also 3D UV patterning. Experimental testing successfully generates complicated patterns with a minimum line-width of 3.36 μm. Direct 3D patterning and 3D microfabrication are also experimentally demonstrated on a photoresist layer. Excellent profile accuracy and surface structure qualities are observed with great potentials for future 2D and 3D microfabrication in a Maskless manner.
Manseung Seo - One of the best experts on this subject based on the ideXlab platform.
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Parameters affecting pattern fidelity and line edge roughness under diffraction effects in optical Maskless Lithography using a digital micromirror device
Optical Design and Testing V, 2012Co-Authors: Manseung Seo, Taehyoung Lee, Haeryung KimAbstract:In optical Maskless Lithography in concern, a digital micromirror device plays the role of a digital mask. Due to the spatial/temporal configuration of micromirror arrays/response or the specification of illumination/projection optics, the irradiance may be influenced by diffraction effects. In present study, an investigation of various optical Maskless Lithography models based on binary micromirror reflections is performed in consideration of the diffraction effect. To evaluate lithographic parameters dissolved in the Lithography models, parametric studies are performed focusing on pattern fidelity and line edge roughness. To reduce corner rounding phenomena due to an image size and further to a reflection criterion, the auxiliary corner reflection adjusting feature (ACRAF) analogous to conventional serif are employed and the effectiveness of ACRAFs is analyzed. The potential of utilizing the adjusted parameters for enhancing pattern fidelity and line edge roughness under diffraction effects is demonstrated through simulations and experiments.
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Optical Proximity Corrections for Digital Micromirror Device-based Maskless Lithography
Journal of the Optical Society of Korea, 2012Co-Authors: Jungyu Hur, Manseung SeoAbstract:We propose optical proximity corrections (OPCs) for digital micromirror device (DMD)-based Maskless Lithography. A pattern writing scheme is analyzed and a theoretical model for obtaining the dose distribution profile and resulting structure is derived. By using simulation based on this model we were able to reduce the edge placement error (EPE) between the design width and the critical dimension (CD) of a fabricated photoresist, which enables improvement of the CD. Moreover, by experiments carried out with the parameter derived from the writing scheme, we minimized the corner-rounding effect by controlling light transmission to the corners of a feature by modulating a DMD.
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Region-based pattern generation scheme for DMD based Maskless Lithography
Lecture Notes in Computer Science, 2006Co-Authors: Manseung Seo, Jae-sung SongAbstract:We focus our attention on complex lithographic pattern generation on a huge substrate with no manipulation of the light source shape for Digital Micromirror Device (DMD) based Maskless Lithography. To overcome the limitations of existing pattern generation methods developed upon the assessment of lithographic paths of the reflected beam spots rather than the recognition of patterns, we place our primary concern on the pattern. We consider pattern generation for Maskless Lithography using the DMD as a graphic recognition field problem. The pattern generation process is conceptualized as dual pattern recognition in two contrary views, which are the substrate's view and the DMD's view. For pattern recognition in the DMD's view, a unique criterion, the area ratio, is devised for approval of the on/off reflection of the DMD mirror. The Region-based Pattern Generation (RPG) scheme based upon the area ratio is proposed. For verification, a prototype RPG system is implemented, and Lithography using the system is performed to fabricate an actual Flat Panel Display (FPD) glass. The results verify that the RPG scheme is robust enough to generate lithographic patterns in any possible lithographic configuration and the RPG system is precise enough to attain the lithographic quality required by the FPD manufacturer.
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GREC - Region-based pattern generation scheme for DMD based Maskless Lithography
Lecture Notes in Computer Science, 2006Co-Authors: Manseung Seo, Jae-sung SongAbstract:We focus our attention on complex lithographic pattern generation on a huge substrate with no manipulation of the light source shape for Digital Micromirror Device (DMD) based Maskless Lithography. To overcome the limitations of existing pattern generation methods developed upon the assessment of lithographic paths of the reflected beam spots rather than the recognition of patterns, we place our primary concern on the pattern. We consider pattern generation for Maskless Lithography using the DMD as a graphic recognition field problem. The pattern generation process is conceptualized as dual pattern recognition in two contrary views, which are the substrate’s view and the DMD’s view. For pattern recognition in the DMD’s view, a unique criterion, the area ratio, is devised for approval of the on/off reflection of the DMD mirror. The Region-based Pattern Generation (RPG) scheme based upon the area ratio is proposed. For verification, a prototype RPG system is implemented, and Lithography using the system is performed to fabricate an actual Flat Panel Display (FPD) glass. The results verify that the RPG scheme is robust enough to generate lithographic patterns in any possible lithographic configuration and the RPG system is precise enough to attain the lithographic quality required by the FPD manufacturer.
Shaolin Zhou - One of the best experts on this subject based on the ideXlab platform.
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Intensity modulation based optical proximity optimization for the Maskless Lithography
Optics express, 2020Co-Authors: Liu Jianghui, Junbo Liu, Qingyuan Deng, Jinhua Feng, Shaolin ZhouAbstract:The undesirable optical proximity effect (OPE) that appeared in the digital micro-mirrors device (DMD) based Maskless Lithography directly influences the final exposure pattern and decreases the Lithography quality. In this manuscript, a convenient method of intensity modulation applied for the Maskless Lithography is proposed to optimize such an effect. According to the pulse width modulation based image recognition of DMD, we replaced the digital binary mask with a special digital grayscale mask to modulate the UV intensity distribution to be closer to the expectation in a way of point-by-point modification. The exposure result applying the grayscale mask has a better consistency with the design pattern than that for the case in which the original binary mask is used. The effectiveness of this method was analyzed by the image subtraction technique. Experimental data revealed that the matching rate between the exposure pattern and the mask pattern has been improved from 78% to 91%. Besides, more experiments have been conducted to verify the validity of this method for the optical proximity optimization and its potential in the high-fidelity DMD based Maskless Lithography.