Fabrication of Large‐Area Periodic Nanopillar Arrays for Nanoimprint Lithography Using Polymer Colloid Masks

Abstract

Thermotropic properties were characterized by differential scanning calorimetry (Perkin-Elmer DSC-7) in conjunction with hot-stage polarizing optical microscopy (DMLM, Leica; FP90 central processor and F82 hot stage, Mettler Toledo). Optically flat glass substrates used in this study included CaF 2 (Almaz Optics, 1 inch diameter (1 inch » 2.5 cm) and 0.125 inch thick, transparent down to 200 nm), and Schott optical glass FK5 (n = 1.4828 at 780 nm, transparent above 320 nm) and SF57 (n = 1.8258 at 780 nm, transparent above 400 nm), both 1 inch diameter and 0.177 inch thick with nearly matched thermal expansion coefficients, 10.0 10 ±6 and 9.2 10 ±6 K ±1 from 20 to 300 C for FK5 and SF57, respectively. All three types of glass substrate were coated with a polyimide layer and then uniaxially buffed for the preparation of glassy nematic films with their thickness controlled by glass fiber spacers (Bangs Laboratory). The light absorption and linear dichroism were characterized using a UV-vis-NIR spectrophotometer (Lambda 900, Perkin-Elmer), and infrared dichroism using a FTIR spectrometer (Nicolet 20 SXC). An AbbØ refractometer (Bellingham and Stanley, Model 60/HR) was used for the measurement of n e and n o with a 780 nm laser (LiCONiX Diolite 800, 6.0±8.0 mW). A solid sample of II was heated to 250 C and then cooled at a rate of ±20 C/min to room temperature for X-ray diffraction using a Rigaku Bragg-Brentano diffractometer equipped with a copper rotating anode and a position sensitive detector. The optics for this instrument were set up to look for a low-angle peak resulting in a narrow X-ray beam irradiating the sample, particularly at higher 2h angles.

Polymeric nanopillar arrays for cell traction force measurements

“…Nanosphere lithography [14,15] uses the self-assembly of monodisperse colloidal nanoparticles to produce silicon nanostructures with tunable size and shape and feature sizes smaller than 10 nm [16,17]. These nanostructures have been used as stamps in nanoimprint lithography [18] used for replication. To fabricate polymeric nanopillar arrays, this technique has been modified by a combination oxygen treatment and deep etching process to produce nano-hole arrays with various diameters and aspect ratios.…”

Growth and characterization of axially periodic Zn2SnO4 (ZTO) nanostructures

“…Organizing nanoscale building blocks into complex nanostructures especially periodic ones, is always a target for researchers [23][24][25][26]. Although the ''top-down'' approach for the fabricating nanostructures has made great progress in the past few years, the fabrication of complex structure in nanoscale is still a challenge [27,28].…”

“…Self-organized growth provides an effective approach for fabrication of these structures. To date, many different morphological nanostructures, including wires, tubes, belts, rods, tetrapods, dendrites as well as other exotic shapes [18][19][20][21][22][23][24][25][26], have been fabricated using different growth methods. In this paper, ternary semiconductor Zn 2 SnO 4 nanowires were prepared using the thermal evaporation method.…”

Linear and Planar Periodic Arrays of Metallic Nanospheres: Fabrication, Optical Properties and Applications

“…NIL has been used to fabricate metamaterials [56][57][58][59][60] and planar periodic arrays of nanoparticles, including arrays of nanospheres. 17,[54][55][61][62][63][64][65][66][67][68][69][70][71][72] This technique presents low cost, high throughput and high resolution, and it can be adopted for areas fabrication of about 1 cm 2 . 53…”