Title :
A self-resonant frequency-modulated micromachined passive pressure transensor
Author :
Baldi, Antonio ; Choi, Woohyek ; Ziaie, Babak
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Univ. of Minnesota, Minneapolis, MN, USA
Abstract :
In this paper, we report on the design, fabrication, and test of a passive pressure transensor. The sensor uses the self-resonant frequency modulation of an integrated coil to detect the pressure variations. This modulation is generated by the relative displacement of a ferrite core attached to a silicone rubber membrane. This scheme simplifies the packaging of the passive transensor by removing the requirement for a separate capacitor to form the resonator. A 30-turn 1.7-μH coil having dimensions of 3×3 mm2 is used in a prototype design yielding a sensitivity of 9.6 kHz/kPa with a cylindrical ferrite core of 0.95-mm diameter and 0.5-mm height. We also present a theoretical model of the sensor that shows good agreement with the experimental data. This model can be a useful tool for further optimization of the senors.
Keywords :
coils; frequency modulation; inductors; membranes; micromachining; microsensors; pressure sensors; transponders; 0.5 mm; 0.95 mm; 3 mm; 9 mm; Integrated coil, microelectromechanical systems (MEMS), micromachining, pressure sensor, transponder.; cylindrical ferrite core; frequency-modulated pressure transensor; integrated coil; micromachined pressure transensor; micromachining; packaging; passive pressure transensor; pressure sensor; pressure variation detection; relative displacement; self-resonant frequency modulation; self-resonant pressure transensor; sensitivity; sensor optimization; silicone rubber membrane; transensor design; transensor fabrication; transensor testing; Biomembranes; Capacitors; Coils; Fabrication; Ferrites; Frequency modulation; Packaging; Prototypes; Rubber; Testing;
Journal_Title :
Sensors Journal, IEEE
DOI :
10.1109/JSEN.2003.820362
