Patterning of Crystalline Organic Materials by Electro‐hydrodynamic Lithography

Abstract

The control of semi-crystalline polymers in thin films and in micrometer-sized patterns is attractive for (opto-)electronic applications. Electro-hydrodynamic lithography (EHL) enables the structure formation of organic crystalline materials on the micrometer length scale while at the same time exerting control over crystal orientation. This gives rise to well-defined micro-patterned arrays of uniaxially aligned polymer crystals. This study explores the interplay of EHL structure formation with crystal alignment and studies the mechanisms that give rise to crystal orientation in EHL-generated structures.

Directing convection to pattern thin polymer films

“…The lines produced by EHP in the work by Schäffer et al20 were 140‐nm wide and 125‐nm tall. The ability to produce small features with a high aspect ratio (0.83) motivated future EHP experiments,59–62 much of it summarized in a review article by Wu and Russel 63. In one study by Wu et al,64 masks with regular topographic structures were employed to create hierarchical arrays of pillars and lines by EHP.…”

“…This represented an order of magnitude increase in patterning resolution over the 1‐μm wide lines present on the mask. Block copolymers62 and crystalline polymers59 have also been employed in EHP so that the micrometer‐scale order imposed by EHP directs their intrinsic, nanometer‐scale structure. EHP is not necessarily limited to polymers; Dickey et al made EHP structures with photopolymerizable liquids so that the room‐temperature pillar formation process occurred in <1 s, much faster than anything previously reported 70, 71…”

Spectroscopic profiling variations in extracellular vesicle biochemistry in a model of myogenesis

“…The most prominent Raman peaks were associated with changes in lipids, proteins and the putative amide I and III bands at 1030, 1160, 1300, 1369, 1450, 1515, 1600 and 1688 cm -1 . [27][28][29][30][31][32][33][34] Changes in these peaks were analysed using a Wilcoxon rank-sum test to determine any statistically significant peak changes between DM-EVs (used as a control) and SM-EVs. p-values less than 0.01 were considered significant.…”

Parametric scheme for rapid nanopattern replication via electrohydrodynamic instability

“…15 With regard to overcoming the limitations of spontaneous instability mediated by interfacial disjoining pressure and high cost of state-of-the-art lithographic techniques, electrohydrodynamic (EHD)-driven patterning, a novel bottom-up pattern fabrication using the electric eld-mediated instability, has drawn substantial attention ever since the pioneering work by Steiner's group. 17 EHD instability (i.e., electric eld-mediated instability) is not merely exploited for pattern transfer in a single-step, noncontact, versatile, and scalable manner, [18][19][20][21][22][23][24] but also provide diverse opportunities for nely tailoring the structural property by carefully selecting process parameters. [25][26][27][28][29][30][31] EHD-driven patterning is based on the phase instability behavior of a thin liquid lm under an applied out-of-plane electric eld that induces undulation of the liquid lm surface to form small patterns; this has been demonstrated experimentally via the fabrication of micro and nanoscale patterns.…”