Patent ID: 8667845

Claim:
Device for detecting elements in a fluid environment comprising: at least one acoustic resonator designed to be disposed in the fluid environment, said at least one acoustic resonator comprising: a plate comprising a piezoelectric layer, said plate being delimited by two opposite longitudinal lateral surfaces; the piezoelectric layer being delimited by two longitudinal lateral surfaces; a surface of the plate designed for fixing of said elements to be detected; an odd number of longitudinal upper electrodes, greater than or equal to three, said upper electrodes being uniformly distributed on a top surface of the piezoelectric layer, each longitudinal lateral surface of the piezoelectric layer being aligned along a longitudinal axis with an edge of an associated upper electrode, two adjacent upper electrodes having an opposite polarity, the upper electrodes of the same polarity being electrically connected to one another; at least one lower electrode being arranged on a bottom surface of the piezoelectric layer opposite to the top surface of the piezoelectric layer; and a generator/detector configured for enabling symmetrical Lamb waves to be generated at a resonance frequency of the acoustic resonator and configured for detecting Lamb waves and providing signals representative of the resonance frequency of the resonator, the generator/detector being electrically coupled to the upper and lower electrodes; an electronic processor connected to the detector and configured for determining a variation of the resonance frequency so as to determine presence of said elements.