Flexible thin film pressure sensor

• Main Authors: LIM HEE C, PETROVA ROUMIANA S
• Format: Patent
• Language: English
• Published: 01.08.2006
• Subjects: MEASURING; MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER,MECHANICAL EFFICIENCY, OR FLUID PRESSURE; PHYSICS; TESTING

Low pressure sensing and imperviousness to corrosion and to the effects of harsh environments are achieved in a pressure sensor that employs a flexible membrane supporting piezoresistive elements. A plurality of piezoresistive elements are aligned substantially collinearly across one surface of the flexible membrane. Innermost piezoresistive elements are disposed in such a way that they experience tension in response to an applied pressure, whereas outermost piezoresistive elements are disposed in such a way that they experience compression in response to the same applied pressure. Contact pads for each end of each piezoresistive element allow the elements to be configured in any number of desirable arrangements. In one exemplary embodiment, four piezoresistive elements are disposed along a main central axis of the membrane. The contacts of the elements are connected to form a Wheatstone bridge. Conventional Wheatstone bridge techniques are utilized to convert an applied pressure into an output electrical signal. The membrane includes amorphous or nanocrystalline semiconductor layers grown on a flexible substrate such as Kapton or suitable plastic materials.