A miniature, high-sensitivity, electron tunneling accelerometer

Prototype low-noise miniature accelerometers have been fabricated with electron-tunneling transducers. The electron-tunneling transducer permits detection of small displacements of the proof mass with high electrical response; such a transducer is essential for a high-performance miniature accelerometer. Prototype accelerometers have shown self-noise of approximately 10(-7) g (Hz)(-1/2) or less between 10 and 200 Hz, and close to 10(-8) g (Hz)(-1/2) near the resonance frequency of 100 Hz. Directivity measurements give nulls at least 50 dB below the maximum. A dual-axis prototype designed for underwater acoustic applications is packaged in an 8 cm(3) volume with a mass of 8 g.