Kazuhiro Miyamura

Blood Plasma Separation Device using Capillary Phenomenon

A microdevice for blood plasma separation using capillary phenomenon has been proposed in this work. Blood plasma can be separated by microcapillary channels fabricated by silicon bulk- micromachining process. The 2 times 3 cm2 device with 1 mm-thick consists of a silicon separation chip and a glass cover. The separation was relatively fast (less than 2 minutes) after a blood-drop (20 mul) was drawn into the channels until the flow stopped. The device was designed for collecting 1 mul of plasma. Due to the advantages in a small sample volume, no power consumption, made the device possible for a blood diagnosis on a chip which promises the applications in point-of-care testing (POCT).

A SILICON MICROCHIP FOR BLOOD HEMOGLOBIN MEASUREMENT USING MULTIREFLECTION STRUCTURE

In this study, a microchip for blood hemoglobin measurement has been investigated. Multireflection structure is used for sensitivity enhancement in absorbance. Glass/silicon bonded structure was used for the microchip to integrate electron/optical devices on a chip. Calibration curve using red coloring matter with 540 nm source was linear from 0.003 to 0.2 absorbance units.

Design and fabrication of blood plasma separation PMMA chip using capillary phenomenon

In this study, a microdevice driven by capillary action has been developed for the high-throughput on-chip separation of plasma from a drop of blood. The microdevice is composed of an array of 2 µm deep and 2 µm wide PMMA (polymethylmethacrylate) channels. This PMMA microfluidic device is fabricated by hot embossing and thermal bonding from a Si master mold. The PMMA device was modified using oxygen plasma and poly-L-lysine in order to obtain a hydrophilic surface. After injection of a blood sample, the plasma flowed rapidly and arrived at the outlet within 3 min, demonstrating a 100% separation ratio of red blood cells. In addition, no hemolysis was observed. Because the proposed blood separation device is driven solely by capillary action, its passive mode of operation eliminates the need for microfluidic pumps or any other additional power supply. It is therefore possible to miniaturize it as an entire system.

Passive Operating On-chip Plasma Isolation From Whole Blood

In clinical chemistry, a necessary step performed is the isolation of plasma from whole blood, and effective sample preparation techniques are needed for the development of miniaturized clinical diagnostic devices. This study demonstrates the use of passive microfluidic devices, which operating entirely on capillary action, for on-chip isolation of plasma from whole blood. Using these devices, several to several tens nanoliter volumes of plasma were effectively separated from a single drop of whole blood in 2 minutes. This study may have broad implications in the design of lab-on-a-chip devices for bioanalytical applications.

Novel Absorption Photometry Microchip with No Reference Solution

In this paper, novel absorption photometry microchip with no reference solution is presented for the first time. The microchip solves the problem about reference solution. The novel microchip, which uses no reference solution, has sensors with three different optical path lengths. The microchip was fabricated using some MEMS process technique, for example silicon anisotropic etching with surfactant added TMAH solution to form 45-degree mirrors. Fabricated microchip was characterized with blood sample, and property of absorption photometry with no reference solution by combining plural optical path was investigated. By proposed method, absorption photometry microchip which is compatible in performance and convenience succeeded in development.