| 摘要 |
PURPOSE:To make a gas sensor thin enough to insert it into even a blood vessel, etc., by covering the gate part of pH sensitive FET and part of a comparison electrode adjoining to the gate part with a hydrophilic polymer and further by covering the polymer layer with a gas permeable polymer. CONSTITUTION:The tip of a silicon wafer worked in a comb tooth shape is surface- nitrified to form gate part 2 and at the other end, electrode part 3 is also formed to obtain FET5. At an internal of distance l of 2mm. or less from gate part 2, comparison electrode 4 is formed by dipping FET in a solution, containing Cl2, after silver is vapor-deposited. Next, electrode part 3 and comparison electrode 4 are fitted with conductor 8 and sensor 5 is inserted into catheter 6 and fixed by electric insulating resin 7. Next, hydrophilic polymer layer 9 that contains an electrolyte is formed while the whole surface of gate part 2 and part of electrode 4 are covered with a polymer such as PVA. Then, gas permeable layer 10 of silicon resin, etc., is provided covering polymer layer 9. Thus, it is made relatively easy to obtain a miniature gas sensor. |
