Akira Nakano

Normally close microvalve and micropump fabricated on a silicon wafer

A normally closed microvalve and micropump were fabricated on a silicon wafer by micromachining techniques. Normally closed microvalve has a silicon diaphragm and a small piezoelectric actuator to drive it. The controllable gas flow rate is from 0.1 ml/min to 85 ml/min at a gas pressure of 0.75 kgf/cm/sup 2/. The micropump is a diaphragm-type pump which consists of two polysilicon one-way valves and a diaphragm driven by a small piezoelectric actuator. The maximum pumping flow rate and pressure are 20 mu l/min and 780 mmH/sub 2/O/cm/sup 2/, respectively.<<ETX>>

Normally closed microvalve and mircopump fabricated on a silicon wafer

Abstract A normally closed microvalve and a micropump are fabricated on a silicon wafer by micro-machining techniques. The normally closed microvalve has a movable silicon diaphragm and a small piezoactuator to drive it. The controllable gas flow rate is from 0.1 ml/min to 85 ml/min at a gas pressure of 0.75 kgf/cm 2 . The micropump is a diaphragm-type pump, which consists of two polysilicon one-way valves and a diaphragm driven by a small piezoactuator. The maximum pumping flow rate and pressure are 20 μ/min and 780 mmH 2 O respectively.

Low-temperature silicon-to-silicon anodic bonding with intermediate low melting point glan

Abstract Room-temperature silicon-to-silicon bonding has been performed. It is an electrostatic bonding using sputtered low melting point glass as an intermediate layer. Wafers can be bonded at room temperature with an applied voltage of about 50 V. This technique is useful for the fabrication of intelligent sensors and microelectromechanical systems.

Roles of Apolipoprotein E Receptors in Lipoprotein Metabolism

Two apolipoprotein E (apoE) specific receptors, designated as ‘very low density lipoprotein receptor’ (VLDLR) and ‘apoE receptor 2’ (apoER2), closely resemble the structure of the low density lipoprotein receptor (LDLR), but they are expressed in different tissues. VLDLR mRNA is abundant in heart, skeletal muscle, brain and adipose tissues, whereas apoER2 mRNA predominates in the brain. In chicken, VLDLR is expressed almost exclusively in oocytes and mediates the uptake of yolk precursors, VLDL and vitellogenin. In contrast to the chicken, where absence of VLDLR results in an inability to lay eggs, the phenotype of VLDLR knockout mice is rather modest, except for a marked reduction of triacylglycerol content in adipose tissue, suggesting that VLDLR plays a part in the uptake of fat into adipocytes. Characterization of the apoER2 gene in various species has revealed the occurrence of an exon loss during its evolution and suggests that exon loss has contributed to the evolution of genes containing repetitive sequences. In addition to apoER2 and VLDLR, we have identified a new LDLR related protein (LRP) that recognizes apoE. This new LRP is expressed in the liver and steroidogenic tissues, suggesting a role in the clearance of apoE-lipoproteins.