A tire mountable apparatus comprising a substrate, the substrate comprising: a first piezoelectric component, the first piezoelectric component comprising first and second conductive layers (212, 214) and a piezoelectric layer arranged between the first and second conductive layers (212, 214); a second piezoelectric component arranged between the first insulating layer and the second insulating layer, the second piezoelectric component comprising third and fourth conductive layers (222, 224) and a second piezoelectric layer arranged between the third and fourth conductive layers (222, 224); a first insulating layer disposed on the first and third conductive layer (212, 222) and a second insulating layer disposed on the second and fourth conductive layer (214, 224) such that the first and second piezoelectric component (210, 220) are arranged between the first insulating layer and the second insulating layer in the substrate; and a conductive terminal structure, characterized in that the conductive terminal structure comprises a plurality of conductive terminals, the plurality of conductive terminals comprising a first conductive terminal electrically coupled to the first conductive layer, a second conductive terminal electrically coupled to the second conductive layer, a third conductive terminal electrically coupled to the third conductive layer and a fourth conductive terminal electrically coupled to the fourth conductive layer; wherein the first conductive terminal is exposed through the first insulating layer of the substrate and the second conductive terminal is exposed through the second insulating layer of the substrate, wherein the third conductive terminal is exposed through the first insulating layer of the substrate and the fourth conductive terminal is exposed through the second insulating layer of the substrate. a first piezoelectric component, the first piezoelectric component comprising first and second conductive layers (212, 214) and a piezoelectric layer arranged between the first and second conductive layers (212, 214); a second piezoelectric component arranged between the first insulating layer and the second insulating layer, the second piezoelectric component comprising third and fourth conductive layers (222, 224) and a second piezoelectric layer arranged between the third and fourth conductive layers (222, 224); a first insulating layer disposed on the first and third conductive layer (212, 222) and a second insulating layer disposed on the second and fourth conductive layer (214, 224) such that the first and second piezoelectric component (210, 220) are arranged between the first insulating layer and the second insulating layer in the substrate; and a conductive terminal structure, characterized in that the conductive terminal structure comprises a plurality of conductive terminals, the plurality of conductive terminals comprising a first conductive terminal electrically coupled to the first conductive layer, a second conductive terminal electrically coupled to the second conductive layer, a third conductive terminal electrically coupled to the third conductive layer and a fourth conductive terminal electrically coupled to the fourth conductive layer; wherein the first conductive terminal is exposed through the first insulating layer of the substrate and the second conductive terminal is exposed through the second insulating layer of the substrate, wherein the third conductive terminal is exposed through the first insulating layer of the substrate and the fourth conductive terminal is exposed through the second insulating layer of the substrate.