Title :
A passive wireless integrated humidity sensor
Author :
Harpster, T.J. ; Stark, B. ; Najafi, K.
Author_Institution :
Centre for Wireless Integrated Microsystems, Michigan Univ., Ann Arbor, MI, USA
Abstract :
This paper presents a single-chip integrated humidity sensor (IHS) capable of wireless operation through inductive coupling with a remote transmitter. The 1.5/spl times/0.5/spl times/8mm/sup 3/ sensor chip consists of a planar electroplated copper coil (20 /spl mu/m thick, 30 /spl mu/m pitch, and 23 turns) and a silicon substrate separated by a 4100-5600 /spl Aring/ polyimide film. The resonant frequency of the IHS changes with humidity and the measured sensitivity ranges from 4-16 kHz/%RH. Measurements show a hysteresis of 4.5%RH over a range of 30-70%RH for a 5600 /spl Aring/-thick polyimide film IHS.
Keywords :
humidity sensors; microsensors; radiotelemetry; remote sensing; Cu; Si; hysteresis; inductive coupling; passive wireless integrated humidity sensor; planar electroplated copper coil; polyimide film; remote transmitter; resonant frequency; silicon substrate; single chip; Coils; Copper; Humidity; Polyimides; Semiconductor device measurement; Silicon; Substrates; Thick film sensors; Transmitters; Wireless sensor networks;
Conference_Titel :
Micro Electro Mechanical Systems, 2001. MEMS 2001. The 14th IEEE International Conference on
Conference_Location :
Interlaken, Switzerland
Print_ISBN :
0-7803-5998-4
DOI :
10.1109/MEMSYS.2001.906601
