Fabrication of Nanogroove Arrays on Acrylic Film Using Micro-Embossing Technique

Abstract

The fabrication of nanostructures is of great importance in producing biomedical devices. Significantly, the nanostructure of the polymeric film has a significant impact on the physical and biophysical behavior of the biomolecules. This study presents an efficient nanofabrication method of nanogroove structures on an acrylic film by the micro-embossing process. In this method, a master mold was made from a thermos oxide silicon substrate using photolithography and etching techniques. An isotropic optical polymethyl methacrylate (PMMA) film is used in the experiment. The acrylic film is known for its excellent optical properties in products such as optical lenses, medical devices, and various general purpose engineering plastics. Then, the micro-embossing process was realized to fabricate nanogroove patterns on an acrylic film by using a micro-embossing machine. However, the morphology of the nanopatterns on an acrylic film was characterized by using an atomic force microscope to measure the dimensions of the nanogroove patterns. The impact of embossing temperature on the morphology of nanogroove patterns on acrylic film is experimentally investigated. The results show that when the embossing temperature is too small, the pattern is not fully formed, and slipping occurs in nanopatterns on the acrylic film. On the other hand, the effect of increasing the embossing temperature on the morphology of nanogrooves agrees with the master mold, and the crests between the nanogrooves form straight edges. It should be noted that the micro-embossing temperature also strongly influences the transferability of nanopatterns on an acrylic film. The technique has great potential for rapidly fabricating nanostructure patterns on acrylic film.

Long-range polymer ordering by directional coating to remarkably enhance the charge carrier mobility in PCDTPT-based organic field-effect transistors

“…The alignment in molecular packing results in a reduction in pi-pi stacking distance and hence an increase in charge transport [24][25][26]. So, for long-range alignment of the molecular backbone and side chains, controlled deposition techniques are required and nano-patterning of the substrate prior to polymer deposition is a potential directional deposition technique among them [27,28]. Lee et al [29] have achieved mobility value as high as 50 cm 2 V −1 s −1 by employing nano-grooved patterning on SiO 2 dielectric and controlled deposition of D-A polymer poly [4-(4,4- [3,4-c]pyridine] (PCDTPT) using sandwich casting system in controlled environment in which PCDTPT vapours reached the substrate (hydrophobic substrate) by tunnelling through glass separator through capillary action.…”

“…The alignment in molecular packing results in a reduction in pi–pi stacking distance and hence an increase in charge transport [ 24 – 26 ]. So, for long-range alignment of the molecular backbone and side chains, controlled deposition techniques are required and nano-patterning of the substrate prior to polymer deposition is a potential directional deposition technique among them [ 27 , 28 ]. Lee et al .…”