Resonator device for measuring stress including at least two resonators with shared cavity

A differential sensing device comprising at least one resonator device for measuring stress, the differential sensing device comprising:

• at least two resonators, each resonator comprising an inter-digitated transducer structure arranged between two reflecting structures on or in a piezoelectric substrate;
• wherein the at least two resonators are arranged and positioned such that they have two different wave propagation directions;
• wherein each resonator comprises at least two parts with an area between the two parts of the at least two resonators forming a cavity, wherein the cavity is shared by the at least two resonators;
• and
• wherein each of the at least two parts of the at least two resonators comprises at least one reflecting structure and a part of the inter-digitated transducer structure of the corresponding resonator.