Pressureless nanoimprinting of anatase TiO2 precursor films

Abstract

Scalable nanoimprint patterning of thin graphitic oxide sheets and in situ reduction J. Vac. Sci. Technol. B 29, 011023 (2011); 10.1116/1.3533936 UV irradiation effect on sol-gel indium tin oxide nanopatterns replicated by room-temperature nanoimprint A soft-imprint method for obtaining anatase TiO 2 nanostructures is reported. The method is de facto pressureless and is performed without the need for dedicated imprint equipment. A titanium butoxide-based sol precursor is prepared with a heavy alcohol, methoxy ethanol, as a solvent. The use of an incompletely cross-linked very soft polydimethylsiloxane mold is found to be crucial for obtaining large-area high-quality imprints. The authors discuss quantitatively the observed substrate-constrained shrinkage of pillars and lines ͑ridges͒ during annealing.

A Universal Scheme for Patterning of Oxides via Thermal Nanoimprint Lithography

“…TiO 2 , ZrO 2 , SnO 2 , GeO 2 and HfO 2 resists containing +4 valency cations were imprinted and heat‐treated as shown in the composite FE‐SEM images (Figure 7). Among these oxides, TiO 2 , due to its outstanding material properties, has been extensively patterned using the sol‐gel route 9, 11, 15. Other oxides may also be imprinted using the sol‐gel method as they form stable chelated alkoxides when reacted with β‐diketones and β‐ketoesters.…”

“…This technique began as a way to replicate mold patterns into a thermoplastic material by heating the polymer above its glass transition temperature and applying pressure on the mold. Variations of this technique extended its adaptability to utilize materials such as thermosets, sol‐gel films, metal‐organic materials and polymerizable liquid metal methacrylate resists to pattern organic as well as inorganic materials, especially oxides 6–18. Direct NIL of oxides has generated tremendous interest due to the fact that their physical properties can be tailored by nanoscale patterning.…”

“…The sol‐gel route with its low‐temperature characteristics, good film quality, and as an economical way to obtain engineered ceramics has attracted a great deal of attention in the imprint technology. In this route, usually an alkoxide or acetate is used as an oxide precursor 6–15. If an alkoxide is used, it is stabilized against hydrolysis by a chelating agent, usually a β‐diketone or β‐ketoester, in an alcohol medium.…”

Nanopatterned Titanium Implants Accelerate Bone Formation In Vivo

“…As metal-based alkoxides cross-links in the presence of water, this reaction can be chemically stabilized and the viscosity of the solution be controlled by incorporating an organic solvent. Previous work by Yoon et al 28 and Richmond et al 29 used solvents with relatively high vapor pressures (6–45 mmHg (20 °C)) leading to rapid evaporation of the solvent, reducing the handling time of the material during the patterning phase to a few seconds. To address this challenge, the sol–gel synthesized in this work featured titanium butoxide mixed with water, diethanolamine (stabilizing agent), and 1-hexanol.…”

Nanocrystalline TiO2 micropillar arrays grafted on conductive glass supports: microscopic and spectroscopic studies

“…c o m / l o c a t e / t s f their direct electrical pathway, which causes a faster charge transport to the electrode, thus greatly reducing recombinations effects and then improving the performance of the optoelectronic devices (Scheme 1). To this purpose, vertically oriented arrays of nanotubes, rods, strips, cones and pillars made of anatase [22][23][24][25][26][27][28][29], rutile [9,[30][31][32] and by mixed anatase-rutile nanostructures [33,34], have been fabricated.…”