A resonator device (200, 300, 350, 370, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500) for measuring stress comprising: at least two resonators (202, 204, 502, 504, 602, 604, 702, 704, 804, 1102, 1104, 1202, 1204, 1302, 1402), each resonator (202, 204, 502, 504, 602, 604, 702, 704, 804, 1102, 1104, 1202, 1204, 1302, 1402) comprising an inter-digitated transducer structure (208, 210, 708, 710, 810, 1108, 1110) and reflecting structures (212, 214, 216, 218, 512, 514, 516, 518, 712, 714, 716, 718, 818, 1108, 1112, 1114, 1116, 1118, 1212, 1214, 1216, 1218) on or in a piezoelectric substrate (206, 306, 406), wherein the at least two resonators (202, 204, 502, 504, 602, 604, 702, 704, 804, 1102, 1104, 1202, 1204, 1302, 1402) are arranged and positioned such that they have two different wave propagation directions, and each resonator (202, 204, 502, 504, 602, 604, 702, 704, 804, 1102, 1104, 1202, 1204, 1302, 1402) comprises two parts with the area between the two parts of the at least two resonators (202, 204, 502, 504, 602, 604, 702, 704, 804, 1102, 1104, 1202, 1204, 1302, 1402) forming a cavity (222, 622, 722, 822, 922, 1022, 1122, 1222, 1422), wherein the cavity (222, 622, 722, 822, 922, 1022, 1122, 1222, 1422) is shared by the at least two resonators (202, 204, 502, 504, 602, 604, 702, 704, 804, 1102, 1104, 1202, 1204, 1302, 1402), and characterized in that one of the two parts of the at least two resonators (202, 204, 502, 504, 804) comprises at least a subset of the reflecting structures (212, 214, 216, 218, 512, 514, 516, 518, 818) comprising at least two of the reflecting structures (212, 214, 216, 218, 512, 514, 516, 518, 818) positioned at various delays and the other one of the two parts of the at least two resonators (202, 204, 502, 504, 804) comprises the inter-digitated transducer structure (208, 210, 810) of the corresponding resonator (202, 204, 502, 504, 804) and the cavity (222, 622, 722, 822, 922, 1022, 1122, 1222, 1422) is not centrally located in between the two resonators. the at least two resonators (202, 204, 502, 504, 602, 604, 702, 704, 804, 1102, 1104, 1202, 1204, 1302, 1402) are arranged and positioned such that they have two different wave propagation directions, and each resonator (202, 204, 502, 504, 602, 604, 702, 704, 804, 1102, 1104, 1202, 1204, 1302, 1402) comprises two parts with the area between the two parts of the at least two resonators (202, 204, 502, 504, 602, 604, 702, 704, 804, 1102, 1104, 1202, 1204, 1302, 1402) forming a cavity (222, 622, 722, 822, 922, 1022, 1122, 1222, 1422), wherein the cavity (222, 622, 722, 822, 922, 1022, 1122, 1222, 1422) is shared by the at least two resonators (202, 204, 502, 504, 602, 604, 702, 704, 804, 1102, 1104, 1202, 1204, 1302, 1402), and characterized in that one of the two parts of the at least two resonators (202, 204, 502, 504, 804) comprises at least a subset of the reflecting structures (212, 214, 216, 218, 512, 514, 516, 518, 818) comprising at least two of the reflecting structures (212, 214, 216, 218, 512, 514, 516, 518, 818) positioned at various delays and the other one of the two parts of the at least two resonators (202, 204, 502, 504, 804) comprises the inter-digitated transducer structure (208, 210, 810) of the corresponding resonator (202, 204, 502, 504, 804) and the cavity (222, 622, 722, 822, 922, 1022, 1122, 1222, 1422) is not centrally located in between the two resonators.