Abstract: A silicon microphone is formed using the steps of providing a first wafer including a layer of heavily doped silicon, a layer of silicon and an intermediate layer of oxide between the two silicon layers. The first wafer has a first major surface on one surface of the layer of heavily doped silicon and a second major surface on the layer of silicon. A second wafer of silicon has a first major surface and a second major surface. A layer of oxide is formed on at least the first major surfaces of the first and second wafers. A cavity is etched through the oxide layer on the first major surface of the first wafer and into the layer of heavily doped silicon. The first major surface of the first wafer is bonded to the first major surface of the second wafer. A metal layer is formed on the second major surface of the second wafer. Acoustic holes are patterned and etched in the metal layer and in the second major surface of the second wafer.

Abstract: The invention comprises a method of fabricating a three-axis accelerometer. A first wafer having a first and a second major surface provided with etching at least two cavities in the first major surface of the first wafer and patterning metal onto the first major surface of the first wafer to form electrical connections for a third accelerometer. A second wafer, etching a portion of a first major surface of the second wafer and bonding the first major surface of the first wafer to the first major surface of the second wafer. The etching and bonding of the surfaces deposit and pattern metallizating, and deposit and pattern a masking layer on the second major surface of the second wafer, defining the shape of a first, a second and the third accelerometer. The first and second accelerometers are formed over the cavities etched in the first major surface of the first wafer.

Abstract: The present invention relates to an apparatus for remote tyre pressure monitoring that is secured onto a wheel surface. The apparatus as a unit comprises or includes a circuit including at least a sensor element to sense air pressure, signal processing circuitry, and data transmitting circuitry and an antenna. The apparatus also comprises or includes a housing at least partially contains the circuit. The housing retains the circuit and the housing and is itself engaged to the wheel surface by adhesive means.

Abstract: The present invention relates to an apparatus for remote tyre pressure monitoring that is secured onto a wheel surface. The apparatus as a unit comprises or includes a circuit including at least a sensor element to sense air pressure, signal processing circuitry, and data transmitting circuitry and an antenna. The apparatus also comprises or includes a housing at least partially contains the circuit. The housing retains the circuit and the housing and is itself engaged to the wheel surface by adhesive means.

Abstract: The invention relates to a method for forming silicon atomic force microscope tips. The method includes the steps of depositing a masking layer onto a first layer of doped silicon so that some square or rectangular areas of the first layer of doped silicon are not covered by the masking layer, etching pyramidal apertures in the first layer of doped silicon, removing the masking layer, depositing a second layer of doped silicon onto the first layer of doped silicon, the second layer of doped silicon being oppositely doped to the first layer of doped silicon and etching away the first layer of doped silicon. Further steps may be added to form the atomic force microscope tips at the end of cantilevers.

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.