We demonstrate a novel microfabricated accelerometer based on optical interferometry principles. This innovative design achieves remarkable sensitivity while maintaining a relatively simple fabrication process.
The accelerometer's core mechanism consists of surface-micromachined interdigital fingers that are alternately attached to:
A proof mass
A support substrate
When illuminated with coherent light, these fingers generate a series of diffracted optical beams. By measuring the intensity of a diffracted beam, we can detect subangstrom displacements between the proof mass and frame.
Two-mask silicon process
Surface micromachining techniques
Simple, cost-effective manufacturing approach
Standard laser diode light source
Conventional photodetector
No complex optical arrangements required
Minimum detectable acceleration: 2 µg/√Hz
Measurement bandwidth: 1 Hz centered at 650 Hz
Sensitivity: Six orders of magnitude below the acceleration of gravity
The technical details of this work are published in: Cooper, E. B., Post, E. R., Griffith, S., Levitan, J., & Manalis, S. R. (2000). High-resolution micromachined interferometric accelerometer. Applied Physics Letters.
Emily Cooper
Rehmi Post
Saul Griffith
Jeremy Levitan
Scott Manalis