Large mass MEMS resonant beam accelerometer
| DWPI Title: Large mass micro-electromechanical system resonant beam accelerometer for converting acceleration vector into measurable shift in resonant frequency of mechanical system, has sensors formed of device layer, and sensing changes in resonant frequencies |
| Abstract: A resonant beam accelerometer employing a pair of double ended tuning forks and a proof mass having meso-scale mass as it is formed in the handle layer of a SOI wafer and a method of fabricating same is disclosed. The resonant frequencies of the pair of double ended tuning forks change in opposite directions when an externally applied acceleration is in a direction parallel to the pair of double ended tuning forks. Due to the proof mass having meso-scale mass, the resonant beam accelerometer is very sensitive. By employing a lid and a stator cap, the active portions of the resonant beam accelerometer may be sealed in a vacuum to further increase sensitivity. |
| Use: Large mass micro-electromechanical system resonant beam accelerometer for converting an acceleration vector into a measurable shift in resonant frequency of a mechanical system. |
| Advantage: The accelerometer uses a stator plate and a lid to ensure foreign particles that do not interfere with operation of the accelerometer, so that the stator plate and the lid permit the accelerometer to be vacuum sealed, thus enhancing operating and sensitivity of the accelerometer. The accelerometer provides an improved semiconductor fabrication technology as doped silicon provides excellent electrical and mechanical properties, which improves manufacturability and performance of devices. The accelerometer uses devices with large proof masses for greater sensitivity without penalty of a limiting and variable fabrication process. The accelerometer increases plane stiffness by employing a thicker device layer and/or wider arms for double ended tuning forks. |
| Novelty: The accelerometer (100) has a set of proof mass flexures (135A-135D) formed of a handle layer and mechanically coupled between a central axis column and a proof mass (115). The set of proof mass flexures permits motion of the proof mass along an acceleration measurement axis (132) with respect to a central anchor column. First and second drivers are formed of a device layer (110), and to cause ones of first and second resonant beam structures (130A,130B) to resonate at first and second resonant frequencies. First and second sensors are formed of the device layer, and senses changes in the resonant frequencies, where each of the resonant frequencies is between approximately 1 kHz and 100 kHz. |
| Filed: 11/16/2022 |
| Application Number: US17988022A |
| Tech ID: SD 15618.1 |
| This invention was made with Government support under Contract No. DE-NA0003525 awarded by the United States Department of Energy/National Nuclear Security Administration. The Government has certain rights in the invention. |
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