Multilevel Hierarchical Topographies by Combined Photolithography and Nanoimprinting Processes To Create Surfaces with Controlled Wetting

Abstract

This work presents a practical methodology to produce multilevel hierarchical structures with precise control of the structural geometry at every level by combining photo and nanoimprint lithography processes. The method involves sequential steps of nanoimprinting of a first deposited polymer layer followed by nanoimprinting of a second deposited layer of a photoresin and, afterward, performing on this layer optical lithography by means of a maskless laser writer to pattern micrometer-size features. A hierarchical topography is consequently obtained comprising nanopatterns and micropatterns at different levels designed independently with very high feature control. The process can be repeated sequentially employing hierarchical working molds produced on a previous fabrication cycle to produce multilevel self-similar hierarchical topographies in a sort of fractal growing manner. The patterning method has broad applicability, as exemplary demonstration, superhydrophobicity, and anisotropic wetting behavior are revealed.

Transparent and Highly Flexible Hierarchically Structured Polydimethylsiloxane Surfaces Suppress Bacterial Attachment and Thrombosis Under Static and Dynamic Conditions

“…[26] Accordingly, a lubricant-infused hierarchical surface would be expected to exhibit excellent biological repellency and strong lubricant retention. Unfortunately, protocols for the fabrication of such hierarchically structured surfaces involve methods, such as photolithography, [29,30] laser ablation, [31,32] electrospinning, [33,34] and emulsion templating, [35] which are either difficult to implement on a wide range of materials and objects with nonplanar form factors or are too complex for commercial scale-up.…”

Impact of surface topography on the bacterial attachment to micro- and nano-patterned polymer films

“…Recently, Alameda et al. [34] employed several steps of photolithography and NIL to fabricate hierarchical structures on different substrates, showing how these topographies exhibit a superhydrophobic behavior. Psochia et al.…”

Mastering of NIL Stamps with Undercut T-Shaped Features from Single Layer to Multilayer Stamps

“…With an imprint stepper or with roll-to-roll NIL also large areas can be patterned three-dimensionally. For fabrication of three-dimensional structures hybrid structuring processes combining NIL and electron beam lithography [ 19 , 20 ] or NIL and photolithography [ 21 ], as well as multilayer nanoimprinting [ 22 ] to create hierarchical stamp masters for optical micro- and nanostructures have been recently demonstrated successfully. Even imprinting of complex three-dimensional nanomolds [ 23 ] was successfully demonstrated.…”