scholarly journals Interfacial Interactions during Demolding in Nanoimprint Lithography

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 349
Author(s):  
Mingjie Li ◽  
Yulong Chen ◽  
Wenxin Luo ◽  
Xing Cheng
Keyword(s):  
Nanoimprint Lithography ◽  
Process Conditions ◽  
Mold Surface ◽  
Interfacial Interactions ◽  
Friction Forces ◽  
Uv Curable ◽  
Structured Materials ◽  
Thermal Expansion Coefficients ◽  
Defect Control ◽  
Commercial Applications

Nanoimprint lithography (NIL) is a useful technique for the fabrication of nano/micro-structured materials. This article reviews NIL in the field of demolding processes and is divided into four parts. The first part introduces the NIL technologies for pattern replication with polymer resists (e.g., thermal and UV-NIL). The second part reviews the process simulation during resist filling and demolding. The third and fourth parts discuss in detail the difficulties in demolding, particularly interfacial forces between mold (template) and resist, during NIL which limit its capability for practical commercial applications. The origins of large demolding forces (adhesion and friction forces), such as differences in the thermal expansion coefficients (CTEs) between the template and the imprinted resist, or volumetric shrinkage of the UV-curable polymer during curing, are also illustrated accordingly. The plausible solutions for easing interfacial interactions and optimizing demolding procedures, including exploring new resist materials, employing imprint mold surface modifications (e.g., ALD-assisted conformal layer covering imprint mold), and finetuning NIL process conditions, are presented. These approaches effectively reduce the interfacial demolding forces and thus lead to a lower defect rate of pattern transfer. The objective of this review is to provide insights to alleviate difficulties in demolding and to meet the stringent requirements regarding defect control for industrial manufacturing while at the same time maximizing the throughput of the nanoimprint technique.

Temperature-induced switchable interfacial interactions on slippery surfaces for controllable liquid manipulation

2019 ◽  
Vol 7 (31) ◽  
pp. 18510-18518 ◽  
Author(s):  
Zubin Wang ◽  
Quan Xu ◽  
Lili Wang ◽  
Liping Heng ◽  
Lei Jiang
Keyword(s):  
Interfacial Friction ◽  
Adhesion Forces ◽  
Interfacial Interactions ◽  
Friction Forces ◽  
Temperature Responsive ◽  
Slippery Surface

The interfacial friction forces and adhesion forces are directly detected and controllable liquid sliding is achieved on a temperature-responsive slippery surface.

Nanoembossed Polymer Substrates for Biomedical Surface Interaction Studies

2007 ◽  
Vol 7 (12) ◽  
pp. 4588-4594 ◽  
Author(s):  
Christopher A. Mills ◽  
Elena Martinez ◽  
Abdelhamid Errachid ◽  
Elisabeth Engel ◽  
Miriam Funes ◽  
...  
Keyword(s):  
Cell Surface ◽  
Methyl Methacrylate ◽  
Nanoimprint Lithography ◽  
Ion Beam ◽  
Biological Species ◽  
Poly Lactic Acid ◽  
Process Conditions ◽  
Thermoplastic Polymers ◽  
Free Standing ◽  
Poly Methyl Methacrylate

Biomedical devices are moving towards the incorporation of nanostructures to investigate the interactions of biological species with such topological surfaces found in nature. Good optical transparency and sealing properties, low fabrication cost, fast design realization times, and bio-compatibility make polymers excellent candidates for the production of surfaces containing such nanometric structures. In this work, a method for the production of nanostructures in free-standing sheets of different thermoplastic polymers is presented, with a view to using these substrates in biomedical cell-surface applications where optical microscopy techniques are required. The process conditions for the production of these structures in poly(methyl methacrylate), poly(ethylene naphthalate), poly(lactic acid), poly(styrene), and poly(ethyl ether ketone) are given. The fabrication method used is based on a modified nanoimprint lithography (NIL) technique using silicon based moulds, fabricated via reactive ion etching or focused ion beam lithography, to emboss nanostructures into the surface of the biologically compatible thermoplastic polymers. The method presented here is designed to faithfully replicate the nanostructures in the mould while maximising the mould lifetime. Examples of polymer replicas with nanostructures of different topographies are presented in poly(methyl methacrylate), including nanostructures for use in cell-surface interactions and nanostructure-containing microfluidic devices.

Effect of process conditions on the properties of surface-modified organic pigments encapsulated by UV-curable resins

2017 ◽  
Vol 134 (1) ◽  
pp. 44-58 ◽  
Author(s):  
O. A. Hakeim ◽  
A. A. Arafa ◽  
M. K. Zahran ◽  
L. A. W. Abdou
Keyword(s):  
Process Conditions ◽  
Uv Curable ◽  
Organic Pigments ◽  
Surface Modified

Flexible Micro-Structured Mold for UV Micro-Casting of Polymeric Microdevices

2009 ◽  
Vol 74 ◽  
pp. 7-10
Author(s):  
L.P. Yeo ◽  
L. Wang ◽  
Zhi Ping Wang ◽  
Yee Cheong Lam
Keyword(s):  
Silicone Rubber ◽  
First Generation ◽  
Potential Method ◽  
Production Method ◽  
Process Conditions ◽  
Uv Curable ◽  
Crosslinked Polymer ◽  
Photosensitive Resin ◽  
Uv Curable Resin ◽  
Silicone Rubber Mold

UV micro-casting is a promising mass production method for replication of polymeric microdevices due to the non-stringent process conditions and fast curing time. This paper describes a potential method to mass produce polymeric microdevices. The first generation mold for UV micro-casting was fabricated by using chemically micro-etched copper clad laminate (CCL) base substrate. Subsequently a two part silicone rubber was cast over the CCL micro-feature mold. Photosensitive resin was dispensed onto the silicone rubber mold and a transparent Mylar thin film was placed on top of the UV curable prepolymer. After the silicone rubber mold-resin-Mylar assembly was UV irradiated for tens of seconds, the crosslinked polymer, together with the Mylar film was peeled off from the mold. The cross-linked polymer was placed on top of a second layer of Mylar film dispensed with the similar UV curable resin. In this way, a complete polymeric micro device could be efficiently produced.

Fluorescent UV-Curable Resists for UV Nanoimprint Lithography

2010 ◽  
Vol 49 (6) ◽  
pp. 06GL07 ◽  
Author(s):  
Kei Kobayashi ◽  
Nobuji Sakai ◽  
Shinji Matsui ◽  
Masaru Nakagawa
Keyword(s):  
Nanoimprint Lithography ◽  
Uv Curable

UV nanoimprint lithography of sub-100nm nanostructures using a novel UV curable epoxy siloxane polymer

2010 ◽  
Vol 87 (11) ◽  
pp. 2411-2415 ◽  
Author(s):  
Dexian Ye ◽  
Pei-I Wang ◽  
Zhuqiu Ye ◽  
Ya Ou ◽  
Rajat Ghoshal ◽  
...  
Keyword(s):  
Nanoimprint Lithography ◽  
Uv Curable ◽  
Siloxane Polymer

Improvement of Transfer Durability of a Pillar-Shaped Release-Agent-Free Replica Mold in Ultraviolet Nanoimprint Lithography

2018 ◽  
Vol 12 (5) ◽  
pp. 723-729
Author(s):  
Junpei Tsuchiya ◽  
Gen Nakagawa ◽  
Shin Hiwasa ◽  
Jun Taniguchi ◽  
◽  
...  
Keyword(s):  
Contact Angle ◽  
Error Rate ◽  
Nanoimprint Lithography ◽  
Low Cost ◽  
Master Mold ◽  
Release Agent ◽  
Uv Curable ◽  
Low Viscosity ◽  
Large Numbers ◽  
Uv Curable Resin

Ultraviolet nanoimprint lithography (UV-NIL) can be used to fabricate nanoscale patterns with high throughput. It is expected to serve as a low-cost technique for the production of items in large numbers. However, master molds for UV-NIL are expensive and laborious to produce, and there are problems associated with the deterioration of the master mold and damage to its nanopattern due to adhesion of the UV-curable resin. Consequently, the UV-curable resin has to combine low-viscosity characteristics for coatability with an antisticking property. Coating a master mold with a release layer is important in preventing damage to the master mold or adhesion between the mold and the UV-curable resin. However, the released layer deteriorates as the master mold is repeatedly used to fabricate nanopatterns. By contrast, the use of a replica mold is a valuable technique for preventing the deterioration of the master mold, and there have been several studies on the fabrication of replicas of master molds with the use of UV-curable resins. In many cases, the fabrication of nanopatterns with replica molds requires the use of a release agent. In a previous study, we developed a material for replica molds that does not require a release agent. This material consisted of a UV-curable resin with an antifouling effect that was prepared from cationically polymerizable UV-curable and epoxy-modified fluorinated resins. With the use of this material, replica molds with patterns of pillars or holes were fabricated with UV-NIL. The lifetime of the mold with the nanopattern of pillars was shorter than that with holes. In addition, the replica mold with the pillar-shaped nanopattern had numerous defects and allowed adhesion of the transfer resin after repeated efforts. Herein, we describe an improved release-agent-free hard replica mold. We transferred large numbers of nanopatterns of pillars from the replica mold, and evaluated the error rate and contact angle of our improved release-agent-free hard replica mold. The resulting release-agent-free replica mold with a nanopattern of pillars was capable of transferring up to 1000 sequential imprints. In addition, to improve the release properties of the transfer resin, we included an additive to the transfer resin that contained a reactive fluorinated material. This material improved the release properties of the transfer resin and mitigated the deterioration of the contact angle and increase in the error rate.

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