Development of large area nano imprint technology by step and repeat process and pattern stitching technique

Cho, Youngtae; Kwon, Sin; Seo, Jung-Woo; Kim, Jeong-Gil; Cho, Jung-Woo; Park, Jung‐Woo; Kim, Hyuk; Lee, Sung‐Hee

doi:10.1016/j.mee.2009.05.004

Cited by 19 publications

(19 citation statements)

References 12 publications

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“…However, the reduction in force holding time is an inherent disadvantage (i.e., causing polymer reflows), which can result in a reduction in embossed pattern quality (He et al, 2007; Ahn & Guo, 2008; Cho et al, 2009). This potential disadvantage can be partially compensated by optimizing the embossing parameters.…”

Section: Introductionmentioning

confidence: 99%

Effects of Preheating and Cooling Durations on Roll-to-Roll Hot Embossing

et al. 2014

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In this study, we examined the sensitivity of embossed pattern depth to preheat supply and cooling and investigated how the pattern type and density affect the embossed depth. The main factors that affect embossed pattern qualities of roll-to-roll hot embossing, such as roller temperature, roller speed, and applied force, were determined using the response surface methodology. Eight conditions were then added to determine the time-dependent effects of heat transfer with custom-designed preheating and cooling systems. An extended preheat time for the polymethylmethacrylate substrate contributed to the significant change in the embossed depth, whereas the substrate-cooling did not exhibit a clear increasing or decreasing trend. Larger embossed depths were achieved in the horizontal patterns with lower density than in the vertical patterns, and the lower pattern densities showed greater embossed depths in most embossing conditions. We expect that this result will help to understand the effects of the pre- and posttreatment of roll-to-roll hot embossing by employing time duration factors of heat transfer, depending on the mold pattern type and density.

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Section: Introductionmentioning

confidence: 99%

Effects of Preheating and Cooling Durations on Roll-to-Roll Hot Embossing

et al. 2014

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“…For the proof-of-concept, we designed a hexagonal microwall without a structure gradient (hexawall) and an inverted pyramidal microwall with a structure gradient (ipyrawall), considering the structural requirements described in Figure B. Our interconnected hexawall (α = 90°) and ipyrawall (α = ∼125°) were fabricated through the UV-NIL process (Figure A,B and see the “Materials and Methods” section), , which are highly compatible with the roll-to-roll (R2R) printing for scalable manufacturing of functional surfaces (Figure C). Additionally, the transparency of our microcavity surfaces as shown in Figure D, is compatible with optical sensing technologies (e.g., surface-enhanced Raman spectroscopy-based biosensor) and other in practical applications (e.g., touch screens) …”

Section: Results and Discussionmentioning

confidence: 99%

“…Here, we proposed a robust particle capture surface that allows the directional particle aggregation of microdroplets by controlling the 3D geometry and surface chemistry of the substrate for low contact transfer from the fomites contaminated by respiratory droplets. Although we focused on the low efficacy of transfer from the contaminated microstructured surfaces to other clean surfaces in this study, we expect that the microcavity surfaces will help limit the contact transfer of various pathogens from contaminated objects (i.e., hands) to recipient surfaces due to their small contact area (∼0.21 for hexawall and ∼0.015–0.03 for ipyrawall). , The efficient particle capturing ability of the microcavity structures not only prevents fomite-based transmission but also may be utilized to preconcentrate target analytes, which may be useful for the environmental monitoring or Raman spectroscopy of pathogens, including SARS-CoV-2. − In addition to the mechanical and chemical stability of surfaces observed after spray cleaning (Figure S10) and the ability to capture particles even without cleaning (Figures S11–13), our engineered surfaces are highly compatible with large-scale manufacturing techniques. ,, For example, we have applied a R2R imprinting process to achieve scalable high-throughput fabrication of interconnected microcavity surfaces (Figure C). With cost-effective large-scale fabrication, our microstructured surfaces will find a wider range of applications in various fields.…”

Section: Discussionmentioning

confidence: 99%

Microstructured Surfaces for Reducing Chances of Fomite Transmission via Virus-Containing Respiratory Droplets

Kim

Nam

et al. 2021

ACS Nano

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Evaporation-induced particle aggregation in drying droplets is of significant importance in the prevention of pathogen transfer due to the possibility of indirect fomite transmission of the infectious virus particles. In this study, particle aggregation was directionally controlled using contact line dynamics (pinned or slipping) and geometrical gradients on microstructured surfaces by the systematic investigation of the evaporation process on sessile droplets and sprayed microdroplets laden with virus-simulant nanoparticles. Using this mechanism, we designed robust particle capture surfaces by significantly inhibiting the contact transfer of particles from fomite surfaces. For the proof-of-concept, interconnected hexagonal and inverted pyramidal microwall were fabricated using ultravioletbased nanoimprint lithography, which is considered to be a promising scalable manufacturing process. We demonstrated the potentials of an engineered microcavity surface to limit the contact transfer of particle aggregates deposited with the evaporation of microdroplets by 93% for hexagonal microwall and by 96% for inverted pyramidal microwall. The particle capture potential of the interconnected microstructures was also investigated using biological particles, including adenoviruses and lung-derived extracellular vesicles. The findings indicate that the proposed microstructured surfaces can reduce the indirect fomite transmission of highly infectious agents, including norovirus, rotavirus, or SARS-CoV-2, via respiratory droplets.

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“…2 High temperature plate type embossing has technical difficulties in temperature uniformity across the work surface, with a difficulty of maintaining the temperature and pressure, so the maximum wafer-level work area is limited to below around 400 mm. 3 Widening the hot embossing equipment is the main issue in the field of hot embossing technology. From the above trends and problems, the roll-to-roll (R2R) hot embossing system has been proposed recently.…”

Section: Introductionmentioning

confidence: 99%

Development of roll-to-roll hot embossing system with induction heater for micro fabrication

Yun

Son

Kyung

et al. 2012

Review of Scientific Instruments

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In this paper, a hot embossing heating roll with induction heater inside the roll is proposed. The induction heating coil is installed inside a roll that is used as a heating roll of a roll-to-roll (R2R) hot embossing apparatus. Using an inside installed heating coil gives the roll-to-roll hot embossing system a more even temperature distribution on the surface of the heating roll compared to that of previous systems, which used an electric wire for heating. This internal induction heating roll can keep the working environment much cleaner because there is no oil leakage compared to the oiled heating roll. This paper describes the principles and provides an analysis of this proposed system; some evaluation has also been performed for the system. A real R2R hot embossing heating roll system was fabricated and some experiments on micro-pattering have been performed. After that, evaluation has been performed on the results.

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Development of large area nano imprint technology by step and repeat process and pattern stitching technique

Cited by 19 publications

References 12 publications

Effects of Preheating and Cooling Durations on Roll-to-Roll Hot Embossing

Effects of Preheating and Cooling Durations on Roll-to-Roll Hot Embossing

Microstructured Surfaces for Reducing Chances of Fomite Transmission via Virus-Containing Respiratory Droplets

Development of roll-to-roll hot embossing system with induction heater for micro fabrication

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