Sensor element for detecting a physical measuring variable between bodies exposed to high tribological strain

US7523670B2 · kind B2 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Klaus Meyer · Ditzingen, DE
• Julius Nemzov · Eßlingen, DE
• Ulrich Mueller · Hamburg, DE

Key dates

• Filing date: Sep 6, 2002
• Grant date: Apr 28, 2009
• Expiry date: Apr 11, 2026

Classification

• Technology area (CPC G): Physics
• CPC primary: G01L5/0085
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The invention proposes sensor elements (5) for detecting a physical measurement variable such as a pressure, a temperature, a gap width, or a capacitance between two bodies (10, 20) that move in relation to each other during operation and experience high tribological stress. In certain areas between the surfaces of the bodies (10, 20) that move in relation to each other, in a surface region of at least one of the bodies (10), a sensitive layer (13, 30), in particular a sensor segment (13), is provided, which is separated from the body (10) by an insulation layer (12) and has a covering layer (14) in a first embodiment. In an alternative embodiment, a surface region of at least one of the two bodies (10) has a recess (23) in which the sensor surface (13) is disposed on the insulation layer (12). In a third embodiment, the sensor surface (13) has a length of 10 μm to 5 mm, a width of less than 5 μm, and a thickness of less than 200 nm.