Patent ID: 8479560
Filing Date: 2013-07-09
Classification: G01N

Abstract:
1. An all-differential resonant sensor apparatus, comprising: a sensing loop including a sensing layer deposited on a sensing resonant beam to detect water vapor concentration in an ambient air, wherein said sensing layer is configured from a matrix of nano composite of sulfonated polystyrene and sulfonated carbon nanotubes; a reference loop including a reference layer in correspondence with said sensing layer deposited on a reference resonant beam, wherein said reference layer possesses visco-elastic properties identical to that of said sensing loop and wherein said reference layer is configured from a matrix of nano composite of polystyrene and carbon nanotubes; and a mixer that detects a difference between a frequency response output from said sensing loop and said reference loop based on absorbed humidity with respect to said sensing resonant beam in order to obtain a drift-free frequency signal.