Abstract: A force sensor comprising a field effect transistor (FET) structure formed on a substrate, having an insulating layer overlying the substrate adjacent to the channel region of the transistor structure. A layer of piezoelectric material overlies the insulating layer, the layer of piezoelectric material having a portion which extends beyond the insulating layer to form a cantilever structure overhanging a portion of the channel region. A control electrode overlies the cantilever structure. Forces acting on the cantilever structure modify the charge distribution in the underlaying channel region, thereby to cause the drain current of the transistor to vary with any variation of force on the cantilever structure.

Abstract: An acoustic surface wave device comprising a monocrystalline body of piezoelectric material having a launching and receiving transducer applied to a planar ASW propagation surface. The piezoelectric material and the orientation of the propagation surface and the axial propagation direction relative to the crystal axes are selected to provide zero piezoelectric coupling between the transducers and a longitudinal axial bulk wave and that one of the two shear axial bulk waves that has substantially no component of particle motion perpendicular to said propagation surface. A method of manufacturing the aforesaid ASW device is also disclosed.

Abstract: An acoustic surface wave filter comprising a monocrystalline wafer of bismuth silicon oxide having a special orientation of the ASW propagation surface and the interdigital transducers relative to the crystal plane whereby pick-up of undesired bulk waves is reduced.