Title :
A Single Chip Integrated Sol-Gel Thin Film LC Sensor for Measuring Moisture in ppm Level
Author :
Islam, Tarikul ; Mahboob, Md Rahat ; Khan, Shoab Ahmed ; Kumar, Lalan
Author_Institution :
Dept. of Electr. Eng., Jamia Millia Islamia Univ., New Delhi, India
Abstract :
A simple single chip integrated moisture sensor capable of wireless operation through inductive coupling has been proposed. The structure consists of planar inductor and parallel plate capacitor fabricated by sol-gel thin film of γ-Al2O3 (5 μm thick). The sensor chip is capable of measuring ppm level moisture in gaseous environment. The resonance frequency shift of the sensor in the presence of moisture excited by a high frequency ac signal is measured by impedance analyzer (4294A Agilent). The frequency sensitivity of the structure for a moisture range from 100 to 5000 ppm is nearly 119 Hz/ppm. The response and recovery times are 7 and 24 s, respectively. The experimental results show that the output is linear (4.2%), reproducible and stable. Device can be applied for wireless moisture measurement in ppm level.
Keywords :
LC circuits; alumina; capacitors; inductors; moisture measurement; sensors; sol-gel processing; 4294A Agilent; Al2O3; frequency sensitivity; gaseous environment; high frequency ac signal; impedance analyzer; inductive coupling; parallel plate capacitor; planar inductor; resonance frequency shift; single chip integrated moisture sensor; single chip integrated sol-gel thin film LC sensor; size 5 mum; time 7 s to 24 s; wireless operation; Films; Humidity; Impedance; Moisture; Resonant frequency; Sensors; Wireless sensor networks; $gammahbox{-}{rm Al}_{2}{rm O}_{3}$ thin film; LC sensor; moisture; ppm; sol-gel method;
Journal_Title :
Sensors Journal, IEEE
DOI :
10.1109/JSEN.2013.2294336
