An all-glass bifurcation microfluidic chip for blood plasma separation was fabricated by a cost-effective glass molding process using an amorphous carbon (AC) mold, which in turn was fabricated by the carbonization of a replicated furan precursor. To compensate for the shrinkage during AC mold fabrication, an enlarged photoresist pattern master was designed, and an AC mold with a dimensional error of 2.9% was achieved; the dimensional error of the master pattern was 1.6%. In the glass molding process, a glass microchannel plate with negligible shape errors (~1.5%) compared to AC mold was replicated. Finally, an all-glass bifurcation microfluidic chip was realized by micro drilling and thermal fusion bonding processes. A separation efficiency of 74% was obtained using the fabricated all-glass bifurcation microfluidic chip.

This study reports a cost-effective method of replicating glass microfluidic chips using a vitreous carbon (VC) stamp. A glass replica with the required microfluidic microstructures was synthesized without etching. The replication method uses a VC stamp fabricated by combining thermal replication using a furan-based, thermally-curable polymer with carbonization. To test the feasibility of this method, a flow focusing droplet generator with flow-focusing and channel widths of 50 µm and 100 µm, respectively, was successfully fabricated in a soda-lime glass substrate. Deviation between the geometries of the initial shape and the vitreous carbon mold occurred because of shrinkage during the carbonization process, however this effect could be predicted and compensated for. Finally, the monodispersity of the droplets generated by the fabricated microfluidic device was evaluated.

A glass microfluidic device with superior chemical and mechanical resistance was fabricated using a cost-effective glass molding process with a vitreous carbon (VC) mold, which was prepared by the carbonization of a replicated polymer precursor. For the development of microfluidic chips with dense microchannels on a large footprint, a defect-free VC mold is essential. In this study, a furan imprinting process, in which a patterned furan layer was imprinted (cured) on a polished furan plate, was established to minimize warpage and gas bubble defects. In addition, the proposed imprinting process markedly reduced the fabrication time of the furan precursor. For feasibility testing, a glass micromixer with a total channel length of 30.6 cm and footprint of 20 × 20 mm 2 was developed by glass molding with the VC mold and thermal fusion bonding. The fabricated glass-molded micromixer was durable at an internal pressure of ~24 MPa, and there was no swelling when used with toluene for an extended time.

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Micro/nano-precision glass molding (MNPGM) is an efficient approach for manufacturing micro/nanostructured glass components with intricate geometry and a high-quality optical finish. In MNPGM, the mold, which directly imprints the desired pattern on the glass substrate, is a key component. To date, a wide variety of mold inserts have been utilized in MNPGM. The aim of this article is to review the latest advances in molds for MNPGM and their fabrication methods. Surface finishing is specifically addressed because molded glass is usually intended for optical applications in which the surface roughness should be lower than the wavelength of incident light to avoid scattering loss. The use of molds for a wide range of molding temperatures is also discussed in detail. Finally, a series of tables summarizing the mold fabrication methods, mold patterns and their dimensions, anti-adhesion coatings, molding conditions, molding methods, surface roughness values, glass substrates and their glass transition temperatures, and associated applications are presented. This review is intended as a roadmap for those interested in the glass molding field.

Solid-state nanopore (SSNP) or synthetic nanopore using semiconductor materials have established themselves as a single molecule bio-detection platform. Although biological nanopore with fixed dimension has been successfully utilized for many sensing applications, SSNP has unique characteristics of distinctly potent geometries and relaxation of modification. The most common method of molecular detection is to measure the temporal variations of the ionic current in the pore. In this review, the principles of the SSNP and the improvement of device performance for the molecular detection platform are discussed elaborately. Moreover, different experimental aspects of the SSNP are discussed in detail. For instance, the enhancement of spatial resolution, modification of temporal resolution with the difficulties of its analyte-detection, as well as reduction of the electrical noise for the improvement of device sensing functionalities, all are addressed in designated chapters for better conception. In addition, the typical and updated applications of SSNP including DNA, protein and virus are briefly discussed. Finally, this article offers the context needed to comprehend current research trends and promote molecular sensing through synthetic nanopores.

The design or dimension of micro-supercapacitor electrodes is an important factor that determines their performance. In this study, a microsupercapacitor was precisely fabricated on a silicon substrate by irradiating an imprinted furan micropattern with a CO2 laser beam under ambient conditions. Since furan is a carbon-abundant polymer, electrically conductive and porous carbon structures were produced by laser-induced pyrolysis. While the pyrolysis of a furan film in a general electric furnace resulted in severe cracks and delamination, the laser pyrolysis method proposed herein yielded porous carbon films without cracks or delamination. Moreover, as the imprinting process already designated the furan area for laser pyrolysis, high-precision patterning was achieved in the subsequent laser pyrolysis step. This two-step process exploited the superior resolution of imprinting for the fabrication of a laser-pyrolyzed carbon micropattern. As a result, the technical limitations of conventional laser direct writing could be overcome. The laser-pyrolyzed carbon structure was employed for microsupercapacitor electrodes. The microsupercapacitor showed a specific capacitance of 0.92 mF/cm2 at 1 mA/cm2 with a PVA-H2SO4 gel electrolyte, and retained an up to 88% capacitance after 10,000 charging/discharging cycles.