Solid state force transducer

Force transducer comprising

• a single crystal of aluminum oxide having a mounting surface and having a crystal face which has selected crystal symmetry and is deformable relative to said mounting surface in response to a force to be measured,
• a piezoresistive strain gage of monocrystalline silicon molecularly integrated directly with said crystal face and responsive to deformation thereof,
• a unitary, effectively rigid ceramic mounting member of high dielectric constant having a surface which mates with said crystal mounting surface,
• and a layer of glass interposed in directly sealed relation between said crystal mounting surface and the ceramic surface,
• the aluminum oxide single crystal, the ceramic mounting member and the glass sealing layer having respective thermal coefficients of expansion which are all substantially equal.

Force transducer comprising

• a single crystal of aluminum oxide having a crystal face with selected crystal symmetry,
• means for supporting said crystal for deformation of said face in response to a force to be measured, and
• a piezoresistive strain gage of monocrystalline silicon molecularly integrated directly with said crystal face and responsive to deformation thereof, said crystal supporting means comprising
• a unitary mounting member of alumina having a first surface which mates with a mounting surface of said single crystal and a second surface which is generally cylindrical,
• a layer of glass interposed in directly sealed relation between said mounting surface of the single crystal and said first alumina surface,
• and a metallic support member including a thin-walled tubular portion enclosing said second alumina surface and directly sealed thereto by a layer of silver.