Study on Polymer Materials Evaluation System for Nano-Imprint Lithography

Tanigawa

et al. 2020

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The leaves of plants belonging to the Araceae family and to the Nelumbonaceae family, represented by the lotus leaf, are known to exhibit water repellency, a property attributed to a double roughness structure having nanostructures on the surface of the leaves. Past research efforts have examined biomimetic structures modeled on the structure of the lotus leaf. The present report presents the results of investigations of a lotus leaf structure transferred onto acrylic resin, made using a live plant as the original material instead of an engineered imitation. The results confirmed that the super water repellency derives from this structure.

Section: Experimental 31 Patterning By Nanocasting and Nanoimprintimentioning

confidence: 99%

Study of Nanoimprinting Plant Structures with Super Water Repellency

Tanigawa

et al. 2020

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“…The nanoimprinting device used here is the LTNIP-5000 manufactured by Litho Tech Japan Corporation [14]. The stamping pressure was 1,000 N, the illuminance of UV light (365-436 nm) 7 mW/cm 2 , and exposure time 5 minutes.…”

Section: Producing Antifouling Sheets For Stentsmentioning

confidence: 99%

The Study of Bile Duct Stent Having Antifouling Properties Using Biomimetics Technique

Aikawa

et al. 2019

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Biomimetics is a field of technologies based on imitating the functions and properties found in living organisms. The application of the super-water-repellent fine structure of lotus leaves to create waterproof products is a well-known example of biomimetics. The present study examined the surface structure of snail shells, which exhibit oleophobic properties oil repellency and explored the feasibility of recreating this structure on the inner surfaces of conventional biliary stents. Observations of snail shells under an electron microscope show a covering of extremely fine protrusions of around 200 nm in size. When water enters the pores between these fine protrusions, a film of water exhibiting supernanohydrophilic structure forms on the shell. Because water and oil are immiscible, this film repels oil. We would expect stent occlusion to be less likely with a biliary stent having this structure on its inner surface. Biliary stricture caused by bile duct cancer or bile duct obstruction can lead to icterus and may, in serious cases, induce fatal hepatic failure. A surgical procedure that places indwelling biliary stents inside the biliary tract is sometimes performed to secure a passage for bile flow. However, conventional stents are prone to occlusion due to the accumulation of biliary sludge, resulting in the need for a second surgery to replace the stent. This problem is attributable to the polyethylene used to make the biliary stents; polyethylene is susceptible to the adhesion of cholesterol and fats found in the bile, eventually leading to stent occlusions. This paper reports our efforts to develop biliary stents that feature antifouling properties inspired by biomimetics to address this problem; specifically, the development of oleophobic inner stent surfaces featuring supernanohydrophilic structures inspired by snail shell surfaces.

“…The Si mold is pressed to the resin layer, and the resin is cured by UV irradiation. The nanoimprint machine LTNIP-5000 [12] (Lithotec Japan Co., Ltd.) was used. In nanoimprint process, the pressing pressure was 1000 N, the UV-light (365 nm ~ 436 nm) intensity was 30 mW/cm 2 , and the exposure time was 5 minutes.…”

Section: Oil Repellent Sheetmentioning

confidence: 99%

Antifouling Effect on Biomimetic Metamaterial Surfaces

Tanigawa

2018

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The snail shells have 200 nm porous structures, and an oil repellent function in water. Three biomimetic structures were fabricated: a silicon black surface, a silicon substrate having nano pillars, and a soft resin sheet having nano pillars. All these structures have equivalent sizes to the real snail shells, and showed good oil repellent effects. The latter two structures have regularly arranged pillars. The last resin sheet was fabricated by using a silicon mold with nano holes and using nanoimprint technologies. As this sheet is soft metamaterial, it can be processed to other shapes. As an example, a tube with oil repellent inner walls was fabricated and evaluated. Good oil repellent and antifouling effect were experimentally obtained from the water-oil mixture flow test. These results indicate the future advances in medical equipment and infrastructure.