COMBINED VAPOR AND/OR GAS CONCENTRATION SENSOR AND SWITCH
A combined vapor and/or gas concentration sensor and switch includes a resonating structure having a first side with a functionalized surface and a second side opposite the first side, a first resonant frequency of a first vibration mode, and a third resonant frequency of a third vibration mode. A d...
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Main Authors | , |
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Format | Patent |
Language | English |
Published |
28.01.2021
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Subjects | |
Online Access | Get full text |
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Summary: | A combined vapor and/or gas concentration sensor and switch includes a resonating structure having a first side with a functionalized surface and a second side opposite the first side, a first resonant frequency of a first vibration mode, and a third resonant frequency of a third vibration mode. A direct current bias source is coupled to the resonating structure. A first AC voltage source is coupled to the drive electrode and provides the resonating structure, via the drive electrode, with a first voltage having an amplitude causing the first vibration mode of the resonating structure to exhibit a pull-in band and having a frequency adjacent the pull-in band of the first mode. A second AC voltage source is coupled to the drive electrode and provides the resonating structure, via the drive electrode, with a second voltage having a frequency corresponding to the third resonant frequency. A read-out circuit is coupled to the sensing electrode and is configured to determine a vapor and/or gas concentration based on a difference between the frequency of the second voltage supplied by the second AC voltage source and a frequency obtained by the read-out circuit. |
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Bibliography: | Application Number: US201917040099 |