Capacitative pressure sensor with transition metal nitride electrode,申请号US20050074775-传众专利搜索

Capacitative pressure sensor with transition metal nitride electrode

申请公布号：US7137302(B2)

申请号：US20050074775

申请日期：2005.03.09

申请公布日期：2006.11.21

申请人：

SILVERBROOK RESEARCH PTY LTD

发明人：SILVERBROOK KIA;MALLINSON SAMUEL GEORGE

分类号：G01L9/12;B60C23/04;G01L1/12

主分类号：G01L9/12

摘要：A pressure sensor ( 30 ) for harsh environments such as vehicle tires, formed from a chamber ( 58 ) partially defined by a flexible membrane ( 50 ), the chamber ( 58 ) containing a fluid at a reference pressure. In use, the flexible membrane ( 50 ) deflects due to pressure differentials between the reference pressure and the fluid pressure, the membrane being at least partially formed from conductive material. A conductive layer ( 36 ) is deposited within the chamber ( 58 ) spaced from the flexible membrane ( 50 ) such that they form opposing electrodes of a capacitor. Associated circuitry ( 34 ) is also deposited for converting the deflection of the flexible membrane ( 50 ) into an output signal indicative of the fluid pressure. The membrane ( 50 ) is at least partially formed from a transition metal nitride because transition metal nitrides are a metal ceramics with high yield strength and metallic bonding that makes it suitable for use in extreme environments. They can also readily include an oxidizing component such as aluminium so that the membrane form a passivating surface oxide layer to protect it from oxidative failure.