Invention:
This invention is a monolithic membrane optomechanical sensor, capable of achieving micro-g sensitivity for acceleration sensing in a monolithic, chip scale platform. It consists of two membranes with differential stiffness on a single silicon chip. Due to the differential stiffness, both the membranes react differently to the actuating force. This displacement between the two membranes can be monitored with high precision using the cavity formed between the two reflecting surfaces.
This kind of sensing can apply to accelerometry, vibrometry, shock and acoustic sensing.
Background:
Microelectromechanical systems (MEMS) integrates four components: microsensors, microactuators, microelectronics, and microstructures in a silicon chip. MEMS sensors are a major component in safety-critical applications and emission control applications in the automotive industry. While this is the main market, optical accelerometers are used for seismic and vibration analysis, inertial measurement, automotive security monitoring, and motion, tilt, and swivel applications in gaming devices.
As technology advances, there has been an increasing need for MEMS sensors to become more accurate and take more measurements. This device is capable of achieving micro-g sensitivity for acceleration sensing and is easily integrated with other advanced photonics devices. Generally, MEMS devices lack the stability and accuracy required for autonomous navigation; more complex and expensive interferometric methods for measuring acceleration are needed. An accelerometer that is accurate, stable and inexpensive to integrate within electronics would be an improvement to the market.
Applications:
- Acoustic sensing
- Vibrometry
- Accelerometry
- Shock
Advantages:
- Achieves micro-g sensitivity
