Three modes of inkless micro-contact printing: contact printing, edge spreading, and channel stamping

Kim, J.H.,Khang, D.Y. Elsevier Sequoia 2014 THIN SOLID FILMS - Vol.571 No.1

Three different modes of printing that use recovered siloxane oligomers from a patterned elastomeric stamp, i.e., contact printing, edge spreading, and channel stamping, have been demonstrated. In contact printing mode, the recovered oligomer molecules are transfer-printed on substrate areas with which the protruding pattern features of the stamp are in intimate contact. When the spacing between protruding features becomes large enough, the printing occurs mainly along the pattern edge, or edge spreading mode. If the spacing between protruding features becomes small enough, on the other hand, the printing occurs on areas where the stamp does not make direct contact with the substrate. These three different modes of inkless micro-contact printing with patterned stamp can extend the applicability of the process for generating various pattern features. Also, possible mechanisms for the observed three different modes of printing have been discussed.

Micro-contact printing of polydiacetylene liposomes using a surface-modified PDMS stamp

유성일,안희준 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.1

Micron-sized polydiacetylene (PDA) liposome patterns have been fabricated on titanium (Ti) substrates using micro-contact printing (μ-CP) techniques. Two types of stamps (PDMS and agarose) and inking methods (“soaking” and “dropping”) are used for μ-CP, and we compare their effect on the morphology of the PDA patterns. When the agarose stamp is inked by the “dropping” method, PDA patterns are most efficiently transferred to the Ti substrate. However, the thickness of the transferred PDA patterns is not homogeneous, with the edge of the transferred pattern being thicker than its center. In contrast, when the PDMS stamp is used for μ-CP, the center of the pattern is thicker than the edge. Red fluorescence patterns are readily obtained by heat treatment of the PDA-immobilized solid substrate.

Aqueous micro-contact printing of cell-adhesive biomolecules for patterning neuronal cell cultures

Min Jee Jang,남윤기 한국바이오칩학회 2012 BioChip Journal Vol.6 No.2

Micro-contact printing (μCP) technique has been widely used for generating micro-scale patterns of biomolecules for patterning live cells. The contactprinting process is carried out in air, while most of the biomolecules including proteins and antibodies should be handled in a solution to preserve their bioactivity. Here we attempted to print biomolecules under aqueous conditions by modifying certain steps that are known to be critical for the bioactivity. The proposed contactprinting process is as follows: After inking the stamp with biomolecule in a solution, the stamp was rinsed in ultra-sonication bath to remove excessive inked biomolecules on the stamp and the following contactprinting process (‘stamping’) was carried out in a buffered solution. By this way, inked biomolecules were consistently handled under a well-defined aqueous condition. Results showed that high-resolution micropatterns of biomolecules can be printed under the aqueous condition (aqueous micro-contact printing, aq-μCP) and it was readily applicable for patterning neuronal cell cultures. Using the modified process, we were able to print widely separated patterns (2 μm-wide lines with 400 μm spacing), which was not achievable with conventional μCP. Extracellular matrix proteins (laminin and fibronectin) were readily printed in a few micrometer scale patterns and their biological activities were confirmed by immunoassays and neuronal cell cultures. We also demonstrated that pH sensitive surface biofunctionalization scheme can be implemented with the proposed aq-μCP for patterning neuronal cell cultures. The aq-μCP improves the existing surface patterning strategy by extending printable patterns and proteins for neuronal cell chip design.

마이크로 컨텍 프린팅 기법을 이용한 결정질 실리콘 태양전지의 전면 텍스쳐링

홍지화,한윤수,Hong, Jihwa,Han, Yoon-Soo 한국전기전자재료학회 2013 전기전자재료학회논문지 Vol.26 No.11

We give a textured front on silicon wafer for high-efficiency solar cells by using micro contact printing method which uses PDMS (polydimethylsiloxane) silicon rubber as a stamp and SAM (self assembled monolayer)s as an ink. A random pyramidal texturing have been widely used for a front-surface texturing in low cost manufacturing line although the cell with random pyramids on front surface shows relatively low efficiency than the cell with inverted pyramids patterned by normal optical lithography. In the past two decades, the micro contact printing has been intensively studied in nano technology field for high resolution patterns on silicon wafer. However, this promising printing technique has surprisingly never applied so far to silicon based solar cell industry despite their simplicity of process and attractive aspects in terms of cost competitiveness. We employ a MHA (16-mercaptohexadecanoic acid) as an ink for Au deposited $SiO_2/Si$ substrate. The $SiO_2$ pattern which is same as the pattern printed by SAM ink on Au surface and later acts as a hard resist for anisotropic silicon etching was made by HF solution, and then inverted pyramidal pattern is formed after anisotropic wet etching. We compare three textured surface with different morphology (random texture, random pyramids and inverted pyramids) and then different geometry of inverted pyramid arrays in terms of reflectivity.

Low-Loss Polymeric Waveguides Having Large Cores Fabricated by Hot Embossing and Micro-contact Printing Techniques

윤근병 한국고분자학회 2004 Macromolecular Research Vol.12 No.5

We present simple, low-cost methods for the fabrication of polymeric waveguides that have large core sizes for use as optical interconnects. We have used both hot embossing and micro-contact printing techniques for the fabrication of multimode waveguides using the same materials. Rectangular and large-core (60  60 m2) channels were readily prepared when using these methods. The dimensions of the embossed and printed channels were the same as those of the pattern on the original master. The polymeric waveguides that we fabricated with large core sizes exhibited a low propagation loss of 0.1 dB/cm at 850 nm, which indicates that hot embossing and micro-contact printing are suitable techniques for the fabrication of optical waveguides having large-core.

Low-Loss Polymeric Waveguides Having Large Cores Fabricated by Hot Embossing and Micro-contact Printing Techniques

Yoon, Keun Byoung The Polymer Society of Korea 2004 Macromolecular Research Vol.12 No.5

We present simple, low-cost methods for the fabrication of polymeric waveguides that have large core sizes for use as optical interconnects. We have used both hot embossing and micro-contact printing techniques for the fabrication of multimode waveguides using the same materials. Rectangular and large-core (60${\times}$60 $\mu\textrm{m}$$^2$) channels were readily prepared when using these methods. The dimensions of the embossed and printed channels were the same as those of the pattern on the original master. The polymeric waveguides that we fabricated with large core sizes exhibited a low propagation loss of 0.1 dB/cm at 850 nm, which indicates that hot embossing and micro-contact printing are suitable techniques for the fabrication of optical waveguides having large-core.

Numerical simulation of ink transfer in micro-gravure-offset printing

황위희(Wei-Xi Huang),이승현(Seung-Hyun Lee),성형진(Hyung Jin Sung),이택민(Taik-Min Lee),김동수(Dong-Soo Kim) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.5

A numerical study of the ink transfer processes that occur during micro-gravure- offset printing is carried out. Specifically, liquid transfer between two parallel separating plates and between a trapezoidal cavity and an upward moving plate are simulated, as models of the printing of ink from the offset pad onto the substrate and the picking up of ink from the gravure plate by the offset pad, respectively. During the liquid transfer between two parallel plates, the stretching, breaking and recoil of the liquid are illustrated, and the generation of a satellite droplet is observed. The influences of the separation velocity, liquid viscosity, surface tension, gravity force, and contact angles on the liquid transfer are estimated. For the transfer of liquid from the cavity to the upward moving plate, the findings indicate that the process can be divided into three stages: 1) a whole stretching stage; 2) a central stretching, breakup and recoil stage; and 3) an equilibrium stage.

Quantitative Measurement of Ink-Blanket Adhesion for Contact Transfer Printing Inks

이아람,김인영,김광영,남수용,최영만 한국정밀공학회 2015 International Journal of Precision Engineering and Vol. No.

In contact transfer printing, perfect ink transfer is determined by the difference of the surface energies between before and after atransfer step. To characterize the difference, one may record the adhesion force by separating the ink film from a substrate by anexternal force. Ink-blanket adhesion is one of the key properties to determine the printability because it affects all steps of the contacttransfer printing. Only a certain range of ink-blanket adhesion properties can get a perfect transfer. Using a lab-made high-precisionforce measuring device, we developed a method to measure the adhesion force during detaching an ink film from a blanket. Inkblanketadhesion can be evaluated quantitatively either as adhesion strength or adhesion energy from the measured adhesion force. Using the proposed method, we assessed the adhesion properties of commercial Ag nanoparticle ink varying the film thickness andthe solid contents.

Quantitative Measurement of Ink-Blanket Adhesion for Contact Transfer Printing Inks

Lee, A-Ram,Kim, Inyoung,Kim, Kwang-Young,Nam, Su-Yong,Choi, Young-Man Korean Society for Precision Engineering 2015 International Journal of Precision Engineering and Vol.16 No.1

In contact transfer printing, perfect ink transfer is determined by the difference of the surface energies between before and after a transfer step. To characterize the difference, one may record the adhesion force by separating the ink film from a substrate by an external force. Ink-blanket adhesion is one of the key properties to determine the printability because it affects all steps of the contact transfer printing. Only a certain range of ink-blanket adhesion properties can get a perfect transfer. Using a lab-made high-precision force measuring device, we developed a method to measure the adhesion force during detaching an ink film from a blanket. Ink-blanket adhesion can be evaluated quantitatively either as adhesion strength or adhesion energy from the measured adhesion force. Using the proposed method, we assessed the adhesion properties of commercial Ag nanoparticle ink varying the film thickness and the solid contents.

Micro-Contact Printing Method for Patterning Liquid Crystal Alignment Layers

Jung, Jong-Wook,Kim, Hak-Rim,Lee, You-Jin,Kim, Jae-Hoon The Korean Infomation Display Society 2006 Journal of information display Vol.7 No.2

We propose a patterning method of liquid crystal (LC) alignment layer for producing multi-domain LC structures. By controlling thermal conditions during micro-contact printing procedures and facilitating wetting properties of patterning materials, patterned LC orientation can be easily obtained on a bare ITO surface or other polymer films. The newly proposed patterning method is expected to be a very useful tool for fabricating multi-domain LC structures to enhance or design electro-optic properties of LC-based devices.