Katsuhiro Matsui

Proposal of a new microreactor for vertical chemical operation

The authors proposed and fabricated a new microreactor stack which would be able to achieve a vertical fluid flow operation for the environment analysis, postgenome analysis, gene diagnosis, and screening of useful materials for medicine manufacture. This reactor is characterized as a simple structure with new aspects of the vertical fluid transportation using a proposed fluid filter with array of micro-through-bores. The deep x-ray lithography process using synchrotron radiation was used for the fabrication of the fluid filter. The feasibility of vertical liquid transportation was investigated using computational fluid dynamics analysis. It is indicated that the vertical liquid transportation is possible using the proposed fluid filter, and high efficiency mixing of liquid was also expected during transportation through the fluid filter. It was confirmed that the fluid flow velocity through the filter can be controlled by varying the load pressure around several kilopascals. A rapid enzyme reaction was s...

Novel Characteristics of Multifunctional Fluid Filters Fabricated by High-Energy Synchrotron Radiation Lithography

A new method using multifunctional fluid filters with through-capillary arrays for high throughput and large-scale integrated microfluidics is proposed. The method utilizes a liquids surface tension and fluid flows perpendicular to a substrate using a fluid filter. Utilizing this method, we can minimize the space consumption of microchannels, and enhance the flexibility of channel design, because these are not extant on the surface of substrates as in traditional microfluidics, but are through-capillary arrays passing through the substrates. In addition, the passive multifunctional characteristics of the fluid filter are favorable for the integration of microfluidics. Therefore, the integration number can be increased from the previous order of hundreds to thousands or more. We conducted a computational fluid dynamics (CFD) analysis to examine the feasibility of vertical fluid flow operation; the multifunctionality of the fluid filter as a microvalve, a microchannel and a micromixer was estimated. The fabrication of the fluid filter by deep X-ray lithography and the vertical fluid flow operation were successfully conducted and the high-throughput properties of the vertical fluid flow were demonstrated.

A New Micro-Chemical Reactor Using Fluid Filters for Vertical Fluid Flow Operation

We proposed and fabricated a new chemical reactor with a vertical fluid flow operation for the environment analysis, post-genome analysis, gene diagnosis, and screening of useful materials for medicine manufacture. This reactor is characterized as a simple structure with new aspects of the vertical fluid transportation induced using a fluid filter with micro-through bores. The deep X-ray lithography process using synchrotron radiation was used for the fabrication of such a fluid filter. Computational fluid dynamics (CFD) simulation results revealed that fluid can be sustained on the surface of the fluid filter and easily transported by pneumatic operation. It was confirmed that the fluid flow velocity through the filter can be controlled by varying the loaded pressure around several kPa. It was demonstrated that the proposed chemical reactor has a good vertical fluid flow operation performance.

Immunoassay Using Microfluid Filters Constructed by Deep X-Ray Lithography

Microfluid filters were fabricated, which possessed 2,100 cylindrical through-bores (φ40 μm) in 200 μm-thickness polymethylmethacrylate (PMMA) sheets (φ3 mm), by deep X-ray lithography using synchrotron radiation. To evaluate the microfluid filters as a device for an immunoassay, we bound the goat anti-mouse immunogloblin G (IgG) antibody to the surface of the filters, and set the filters between reaction vessels stacked vertically in a microreactor. An enzyme-linked immunosorbent assay (ELISA) of mouse IgG using the goat anti-mouse IgG/horseradish-peroxidase (HRP) conjugate indicated that mouse IgG could be quantitatively detected in the range of 0–100 ng/ml, demonstrating the applicability of vertical microfluidic operation to the immunoassay.