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Electron beam nanoimprint lithography was proposed for fabricating the
micro-/nanostructures of cross-linked poly(L-lactic acid) (RX-PLLA).
PLLA with triallyl isocyanurate (TAIC) solutions were dropped on the
Si-molds fabricated by the conventional EB lithography technique.
PLLA/TAIC on Si-molds were imprinted and cross-linked with doses from 10
to...
Context in source publication
Context 1
... RX-PLLA-100kGy, in the preliminary experi- ments of general autocleave sterilization, thermal resistance at 120 C was observed. Figure 4 shows the AFM image of an imprinted micro-/nano-designed pattern after heat treatment. It is found that the imprinted patterns were maintained even after heating at 120 C for 20 min. ...
Citations
... The evolutions of T g and T m shown in Figure 1E make it clear that PLLA and TAIC are thermodynamically miscible blends. According to our analysis of the SEM and DSC results, the miscibility between PLLA and TAIC is confirmed, which agrees with results previously reported in the literature [29][30][31][32]. This will be the basis for the following investigation of inclusion and exclusion behaviors of TAIC during the crystallization of PLLA. ...
... The evolutions of Tg and Tm shown in Figure 1E make it clear that PLLA and TAIC are thermodynamically miscible blends. According to our analysis of the SEM and DSC results, the miscibility between PLLA and TAIC is confirmed, which agrees with results previously reported in the literature [29][30][31][32]. This will be the basis for the following investigation of inclusion and exclusion behaviors of TAIC during the crystallization of PLLA. ...
In this work, PLLA/TAIC has been taken as a model system to investigate the inclusion and exclusion of small molecules during the crystallization of polymers in their miscible blend. Our results indicate that it is the growth rate and diameter of PLLA spherulites that dominate the localization of TAIC. On the one hand, crystallization temperature plays an important role. Crystallization at higher temperature corresponds to higher growth rates and a greater diameter of PLLA spherulites. The former improves the ability of PLLA crystals to trap TAIC while the latter leads to a lower volume fraction of space among neighboring PLLA spherulites. The combination of the two contributes to the enhanced inclusion behaviors. On the other hand, when compared to melt crystallization, cold crystallization results in much smaller spherulites (from higher nucleation density) and sufficient space among spherulites, which accounts for the enrichment of TAIC in interspherulitic regions and for its enhanced exclusion. In the adopted polymer–small molecule blend, TAIC can enrich in interspherulitic regions even in its miscible blend with PLLA, which can be attributed to its stronger diffusion ability.
... E-beam lithography (EBL) is a widely used patterning technique for nanofabrication in industry and academy, for its capability of high-resolution patterning and controllability without a mask [36][37][38]. However, there is the fact that a manufactured pattern differs from the one input to the EBL software. ...
The fabrication of a nanostructure with a size of hundreds of nanometers down to sub- 20 nm is investigated and demonstrated by e-beam lithography (EBL). The proximity effect influenced by the exposure dose during EBL is explored and analyzed for both pillar and grating patterns with positive and negative photoresist. By good control of the proximity effect and etching process, grating patterns from hundreds of nanometers down to about 20 nm are obtained. Furthermore, a pillar structure with a size down to sub-20 nm is achieved by annealing treatment of the photoresist hydrogen silsesquioxane at 400 °C without any further etching process. These nanostructures show great potential for efficiency enhancement of organic light-emitting diodes (OLEDs). The finite element analysis demonstrates there is the possibility of enhancing the external quantum efficiency of OLEDs peaking at 510 nm by a factor of 1.4. Such a high enhancement factor can only be achieved with finely controlled nanostructures, indicating the importance of size control during nanofabrication.
... Nanoimprint lithography (NIL) is one of the most promising technologies for fabricating polymeric materials with a high throughput and at a low cost, 2 and the application of thermal NIL to PLLA has already been demonstrated. 3,4 Our research group has proposed an electron beam (EB)-NIL, which enables simultaneous radiation-polymerization/-crosslinking and device fabrication, 4,5 and demonstrated the micro/nanofabrication of radiation-crosslinked PLLA, which has high thermal stability. 4 However, the possible resolution of NIL is limited by the molds that transfer the patterns to the polymers. ...
... Nanoimprint lithography (NIL) is one of the most promising technologies for fabricating polymeric materials with a high throughput and at a low cost, 2 and the application of thermal NIL to PLLA has already been demonstrated. 3,4 Our research group has proposed an electron beam (EB)-NIL, which enables simultaneous radiation-polymerization/-crosslinking and device fabrication, 4,5 and demonstrated the micro/nanofabrication of radiation-crosslinked PLLA, which has high thermal stability. 4 However, the possible resolution of NIL is limited by the molds that transfer the patterns to the polymers. ...
... 3,4 Our research group has proposed an electron beam (EB)-NIL, which enables simultaneous radiation-polymerization/-crosslinking and device fabrication, 4,5 and demonstrated the micro/nanofabrication of radiation-crosslinked PLLA, which has high thermal stability. 4 However, the possible resolution of NIL is limited by the molds that transfer the patterns to the polymers. 2,3 Meanwhile, top-down processing using quantum beams (highly controlled artificial radiation) are powerful micro/nanofabrication techniques. ...
Micro/nanofabrication of biocompatible and biodegradable poly(L-lactic acid) (PLLA) using focused Ga ion beam direct etching was evaluated for future bio-device applications. The fabrication performance was determined with different ion fluences and fluxes (beam currents), and it was found that the etching speed and fabrication accuracy were affected by irradiation-induced heat. Focused ion beam (FIB)-irradiated surfaces were analyzed using micro-area X-ray photoelectron spectroscopy. Owing to reactions such as the physical sputtering of atoms and radiation-induced decomposition, PLLA was gradually carbonized with increasing C=C bonds. Controlled micro/nanostructures of PLLA were fabricated with C=C bond-rich surfaces expected to have good cell attachment properties.
... EB-NIL can cure the monomer (or oligomer) without photo-initiator, and can modify the characteristics of polymer. Moreover, it does not need any requirements, as is the case of UV-NIL, for the mold materials [8,9]. ...
Nano-/micro-scale structures of transparent crosslinked polytetrafluoroethylene (RX-PTFE) mold have been fabricated by combined process which is thermal and radiation process for fabrication of RX-PTFE (TRaf process). The nano-/micro-fabricated RX-PTFE were attempted to be applied for the transparent polymer molds of UV nanoimprint lithography (NIL). The ability of the RX-PTFE mold for UV-NIL was evaluated by the imprinted patterns. The RX-PTFE molds and the imprinted structures obtained by UV-NIL were observed by a field emission scanning electron microscope (FE-SEM). As a result, imprinted structures of photo-curable resin (Trimethylolpropane-triacrylate: TMPTA) by UV-NIL using RX-PTFE mold were successfully obtained. The nano-scale L&S patterns, square (410 nm × 410 nm) and hole (Φ{phonetic} 170 nm) array patterns were clearly obtained.
