Thin-film coating on cylinder for fabrication of cylindrical mold: Roll-to-roll nano-imprint lithography

Tahir, Usama; Kamran, Muhammad Ahmad; Jang, Min Hyeok; Jeong, Myung Yung

doi:10.1016/j.mee.2019.03.004

Cited by 13 publications

(5 citation statements)

References 21 publications

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“…The tension module is responsible for creating tension at the two ends of the PET film so that the film moves properly into the imprinting process. The dispensing module consists of a resin cylinder that can possibly evacuate the bubbles from the resin and drop-casting unit [15]. The adjusting module adjusts the wrap angle between the stamp roller and the PET substrate.…”

Section: Methodsmentioning

confidence: 99%

“…Jain et al [9] derived a mathematical model for droplet dispensing of UV resin on the substrate. For imprint material, they used the Maxwell model due to the material's viscoelastic nature and discussed different processing parameters such as the merging of droplets on the substrate, the peeling off of the resist layer, the exposure time, and the pressure profile of the imprint layer by using lubrication theory [14,15]. Ye et al [12,13] categorized numerical models for bubble entrapment with regular bubbles and irregular bubbles during the R2R imprinting process.…”

Section: Introductionmentioning

confidence: 99%

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Numerical Study on the Optimization of Roll-to-Roll Ultraviolet Imprint Lithography

2019

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Roll-to-roll ultraviolet (R2R-UV) imprinting is a low-cost and high-throughput method that includes the manufacturing of large-area functional films. However, the quality of the final product is obstructed by the bubble entrapment during the imprinting process. In this study, a multi-phase volume of fluid (VOF) numerical model was used to remove bubble entrapment during the R2R imprinting process, which covered all parameters. This new modified numerical model with open-channel boundary conditions was based on the single zone that contains the direct contact of UV resin with the imprinting mold during the filling process. In addition, this model simulated the UV resin filling into microcavities at the preceding and succeeding ends of the imprinting mold. Different patterns of imprinting mold were considered to enhance the fidelity of R2R-UV imprinting for the comprehensive analysis. The experimental results validated through numerical simulations revealed that the bubble entrapment can be controlled by varying various parameters such as speed of the imprinting system, viscosity, contact angles, and pattern shape. The proposed model may be useful for a continuous bubble-free R2R imprinting process in industrial applications that includes flexible displays and micro/nano-optics.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Numerical Study on the Optimization of Roll-to-Roll Ultraviolet Imprint Lithography

2019

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“…Only existing liquid on the cylinder flows over the outer surface of the cylinder.The present analysis is a mathematical modeling of an industrial technique where the key aspiration is to develop a very thin uniform layer of liquid that can be used as a coating substance. This study may give more knowledge to understand and design different polymer processing equipment, micro/nanostructural fabrication, coating of a wire and fiber, and so forth (see, Tahira et al 46 and Mun et al 47 ).…”

Section: Introductionmentioning

confidence: 99%

Thermocapillary thin film flow upon a porous heated stretchable cylinder

Gogoi,

Maity

2023

Heat Trans

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Earlier research work related to the unsteady flow of thin liquid film on a heated stretching cylinder has considered the boundary‐layer approximation under the assumption that the film thickness is thick. In this article, we have considered the full set of Navier–Stokes equations to study the unsteady film development over a porous heated stretching cylinder with the assumption that film height either coincides or lies within the boundary‐layer thickness. The effects of magnetic field, suction/injection, and cooling or heating of the cylinder have been considered for investigation. The governing set of coupled nonlinear partial differential equations is solved numerically by the implicit finite difference scheme (Crank–Nicolson). It was found that the film thinning rate diminishes with rising values of the porosity parameter and Hartmann number. It is also noted that the film thickness is enhanced for injection whereas opposite results are observed for suction through the porous cylinder. The thermocapillary effect showed that the thinning rate of the liquid film decreases or increases according to the surface of the cylinder being heated or cooled. It is observed that continuously increasing the stretching speed of the cylinder produces faster thinning of the liquid film. The temperature of the liquid film is the maximum at the surface of the cylinder and it decreases toward the free surface when the cylinder is heated. But the opposite phenomenon occurs when the cylinder is cooled.

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“…The smooth fabrication process has various defects because of the incomplete filling of the UV resin into the nanopatterns from the left/right (based on the filling direction) end of the imprint mold. Several studies [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ] were conducted in the literature to optimize the filling processes. Pietarinen et al [ 10 ] introduced the micro-optics replication process with the solvent-assisted filling into the micro-pyramid structures to avoid the defects due to air entrapment.…”

Section: Introductionmentioning

confidence: 99%

Process Optimization for Manufacturing Functional Nanosurfaces by Roll-to-Roll Nanoimprint Lithography

et al. 2022

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Roll-to-roll nanoimprint lithography (RTR-NIL) is a low-cost and continuous fabrication process for large-area functional films. However, the partial ultraviolet (UV) resin filling obstructs the ongoing production process. This study incorporates UV resin filling process into the nanopillars and nanopores by using RTR-NIL. A multiphase numerical model with a sliding mesh method is proposed in this study to show the actual phenomena of imprint mold rotation and feeding of UV resin on the polyethylene terephthalate (PET) substrate. The implementation of UV resin filling under environmental conditions was performed by utilizing the open-channel (OC) boundary conditions. The numerical model was solved by using the explicit volume of fluid (VOF) scheme to compute the filling on each node of the computational domain. The effects of different processing parameters were investigated through the proposed numerical model such as imprinting speed (IS), contact angles (CAs), viscosity, initial thickness of the PET, and supporting roll diameter. A good agreement was found between numerical simulations and experimental results. The proposed numerical model gives better insights of the filling process for the mass production of functional surfaces with nanopillars and nanopores patterns for different applications on an industrial scale.

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Thin-film coating on cylinder for fabrication of cylindrical mold: Roll-to-roll nano-imprint lithography

Cited by 13 publications

References 21 publications

Numerical Study on the Optimization of Roll-to-Roll Ultraviolet Imprint Lithography

Numerical Study on the Optimization of Roll-to-Roll Ultraviolet Imprint Lithography

Thermocapillary thin film flow upon a porous heated stretchable cylinder

Process Optimization for Manufacturing Functional Nanosurfaces by Roll-to-Roll Nanoimprint Lithography

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