Gas sensors based on quartz crystal microbalance for classification of volatile organic compounds

Electronic noses are systems that try to mimic the human nose. Currently gas sensors based on quartz crystal microbalance are frequently used to form such systems. These sensors have a sensing film deposited by the method of ultrasonic atomization. The sensor sensitivity is proportional to the square of the resonant frequency, therefore if it is desired to increase the sensitivity is necessary to increase the work frequency. In this we work show results with sensors whose fundamental frequency is 20MHz. The responses to ethanol are presented for seven sensors, each with a different sensing film. The sensitivities of the sensors were studied and it was found that the most sensitive sensor was Ethyl Cellulose. A comparison of the sensitivities between sensors with the same sensing film but with different working frequency (12MHz and 20MHz) was performed, being the most sensitivity the sensors of 20MHz.