Abstract: Devices fabricated on a wafer are encapsulated by forming a pattern of bond rings on a cap wafer and aligning and bonding the two wafers together, under thermo-compression, so that an operational part (22) of each device (20) is surrounded by a respective bond ring (21). The bond ring provides a hermetic seal by occupying any trenches (25) or other discontinuities, such as conductive tracks (23), in the upper surface of the device crossed by the ring. An accelerometer is manufactured by etching at least one cavity (5) into the top side of a substrate (1), bonding an intermediate layer of material (6) onto the top side of the substrate, depositing metallization (7) onto the intermediate layer and etching the metallization and intermediate layer to form a sensor structure suspended over each cavity.