Title :
A novel flow sensor with high time resolution based on differential pressure principle
Author :
Richter, M. ; Wackerle, M. ; Woias, P. ; Hillerich, B.
Author_Institution :
Fraunhofer-Inst. for Solid State Technol., Munich, Germany
Abstract :
In this paper, a novel flow sensor for liquids is presented. This concept allows a simple one-chip solution based on an established technology. The sensor consists of a common piezoresistive pressure sensor with an orifice in the sensor diaphragm, which forms a flow restriction. If the diameter of the orifice is made large compared to the thickness of the pressure sensor membrane, the flow signal becomes temperature-independent. Experiments have shown, that the time resolution of the sensor is in the order of one millisecond. Further, gas bubbles cause a blocking effect the threshold pressure of which varies between a few hPa at large orifices and about hundred hPa at small orifices.
Keywords :
diaphragms; flowmeters; membranes; microsensors; piezoresistive devices; pressure sensors; FEM simulation; Hagen-Poiseuille law; Hagenbach correction; blocking effect; differential pressure principle; flow restriction; flow sensor; gas bubbles; high time resolution; laser drilling; liquid flow; membrane thickness; microsensor; one-chip solution; orifice diameter; piezoresistive pressure sensor; rapid prototyping; sensor diaphragm; temperature-independent flow signal; threshold pressure; transient flow; Atmospheric measurements; Biomembranes; Drilling; Fluid flow measurement; Orifices; Piezoresistance; Pressure measurement; Silicon; Stress; Temperature sensors;
Conference_Titel :
Micro Electro Mechanical Systems, 1999. MEMS '99. Twelfth IEEE International Conference on
Conference_Location :
Orlando, FL, USA
Print_ISBN :
0-7803-5194-0
DOI :
10.1109/MEMSYS.1999.746783
