It is reported that a team from A*STAR, a microelectronics research institute in Singapore, has produced a small sensor. The team's main goal is to create an implantable micro-medical device. Now this goal needs to rely on a wide range of sensors. Circuit research and testing. This sensor combines a stable diaphragm with an easily-sensing silicon nanowire, making the MEMS pressure sensor more stable and suitable for medical devices.
In principle, designing a small pressure sensor is simple: a pressure deformable diaphragm can be embedded in a varistor. The varistor must be made of silicon nanowires, etc., which can cause resistance changes due to pressure. Made of materials. But in fact there will be problems, including circuit design and fragile components, where errors anywhere are commercial sensors.
Since the diaphragm must transmit a small pressure change to the varistor and at the same time resist deformation and breakage, the choice of diaphragm material is crucial. So Luo and his colleagues thought of using silicon dioxide to show perfect pressure sensing performance. However, although silicon dioxide has superior sensing performance, it cannot overcome the weakness of bendability. Therefore, Luo changed the solution to use double-layered silicon dioxide, while placing piezoresistive silicon nanowires in between, and adding a layer of stable silicon nitride to the top layer.
By etching silicon nitride and varying thickness, adjusting silicon nanowires, the team finally found the optimal combination. The last sensor successfully satisfies the resistance to deformation and mechanical damage while still providing linear changes in pressure-sensing output, meeting the requirements for high-precision medical device applications.
Singapore Develops New MEMS Pressure Sensor
2022 01/11