Exploring fiber optic approach to sense humid environment over nano-crystalline zinc oxide film.
A novel humidity sensor made up of nano-crystalline zinc oxide (ZnO) film, coated onto the U-shaped typical glass substrate as a wave guide, conjugated with an optical fiber and He-Ne un-polarized laser source. The nano-crystalline zinc oxide (ZnO) was synthesized using single molecular precursor method. The resulting material was characterized with Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD), thermogravimetric-differential thermal analysis (TG-DTA) and scanning electron microscopy (SEM). In the thin film, ZnO particles exhibited the wurtzite phase structure with the particle size in a diameter range of 70-80 nm. The humidity sensing characteristic has been estimated by measuring the optical permeability (OP) as a function of percentage relative humidity (%RH) in the ranging from 5 to 90 inside a closed chamber. The OP decreases linearly with increase in %RH with a respond time of about 30 and recovery time of 35s. The sensor exhibits the sensitivity of 0.45 in the %RH range 5-50 and 0.30 from 50 to 90.
Shukla
S K
SK
Department of Polymer Science, Bhaskaracharya College of Applied Sciences, University of Delhi, New Delhi, India. sarojshukla2003@yahoo.co.in
Tiwari
Ashutosh
A
Parashar
G K
GK
Mishra
A P
AP
Dubey
G C
GC
D003460:Crystallization; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods*; D006813:Humidity; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods; D055100:Optical Fibers; D010316:Particle Size; D015203:Reproducibility of Results; D017550:Spectroscopy, Fourier Transform Infrared; D015034:Zinc Oxide / Q000737:chemistry*
D015034:Zinc Oxide