Filling Behavior and Mold Release Force in UV Nanoimprinting Using PDMS Mold in Different Atmosphere

Abstract

Bubble-free filling needs to be achieved to realize high-throughput mass production in ultraviolet nanoimprint lithography (UV-NIL). Polydimethylsiloxane (PDMS) is a gastransmittable material because of its molecular features and is used as the base material for flexible molds in large-area UV-NIL. In this work, we investigated the filling behavior and mold release force of UV-NIL using a soft UV-curable PDMS mold in different atmospheres. Bubble-free filling was successfully demonstrated in air and 1,1,1,3,3-pentafluoropropane (PFP) gas atmosphere. The average release force following UV-NIL in PFP was 5.2 N, which was 70% smaller than that following UV-NIL in air. Defect-free fine nanopatterns with a width of 300 nm were fabricated by UV-NIL in PFP atmosphere.

Study of Nanoimprinting Plant Structures with Super Water Repellency

“…Figure 2 illustrates the nanocasting method [5,6]. First, a plant leaf is fixed inside a Petri dish, onto which an Si-based resin PDMS is poured [9]. Before the resin is poured, a mold release agent was sprayed onto the leaf and allowed to dry.…”

“…At this point, the PDMS was released from the leaf and ready to use as a transcript mold. Figure 3 shows the scheme of the nanoimprinting method [9,10]. First, a mold release agent was sprayed onto the PDMS transcript mold obtained in Fig.…”

“…The study reported on here used a live plant as the source of the structure, which was transferred onto PDMS [6] by the nanocasting method [7,8]. The PDMS transcript was subsequently used as a mold for retransferring the structure onto acrylic resin by the nanoimprinting method [9,10]. This paper reports on investigations carried out to determine whether water repellency is reproduced in the acrylic resin transcript and whether the water repellency derives from the structure itself.…”

UV-Nanoimprinting Lithography Photoresists with No Photoinitiator and Low Polymerization Shrinkage

“…UV-nanoimprinting lithography (UV-NIL), having the advantages of high throughput, good resolution, and low manufacturing cost, as well as room-temperature operation, is regarded as the new next-generation lithography technique and has been receiving increasing attention in recent years. − However, polymerization shrinkage of the photoresist used for UV-NIL is still regarded as a critical problem which hinders a wide array of applications of UV-NIL technology, because it severely impacts the nanoimprint patterns’ resolution . Therefore, decreasing the photoresist’s polymerization shrinkage during the photopolymerization reaction is still a big challenge .…”

Thermal nanoimprint lithography of sodium hyaluronate solutions with gas permeable inorganic hybrid mold for cosmetic and pharmaceutical applications

“…12,13) Compared with lithography techniques that require large and expensive equipment with facilities, such as photolithography, 14,15) extreme ultraviolet lithography, 16,17) electron beam lithography, 18,19) and ion beam methods, 20,21) the nanoimprint lithography of simple molding processes is a low-cost and high-productivity technology that can be applied to various transferred function materials, large areas, and pattern transfer with high aspect ratio and resolution. [22][23][24][25] However, the high viscosity of the imprint materials makes fabrication difficult because gas microbubbles are easily trapped in the gas-impermeable molds. 26,27) Furthermore, the gas traps of water and volatile solvents in the imprint materials cause transfer failure in conventional nanoimprint lithography using conventional gas-impermeable quartz and metal molds to broaden the application field of imprint materials comprising volatile solvents such as cosmetics and pharmaceuticals.…”