New breakthrough in MEMS pressure sensor research for medical devices

According to reports, a team from A*STAR, a microelectronics institute in Singapore, produced a small sensor. The main goal of the team is to create an implantable micro- medical device . Extensive circuit research and testing. This sensor combines a stable diaphragm with easy-to-sensing silicon nanowires, making the MEMS pressure sensor more stable and durable for medical devices.

In principle, it is very simple to design a small pressure sensor: a pressure-deformed diaphragm can be embedded in a varistor. This varistor must be resistant to changes in resistance caused by pressure, such as silicon nanowires. Made of materials. But in fact there are problems, including circuit design and fragile components, where any error is a fatal injury to commercial sensors.

Since this diaphragm must transmit small pressure changes to the varistor while resisting deformation and breakage, the choice of this diaphragm material is critical. So Luo and his colleagues thought of using silica to show perfect pressure sensing performance. However, although silica has superior sensing properties, it cannot overcome the weakness of flexibility. Therefore, Luo changed the solution to use double-layered silicon dioxide, while placing the piezoresistive silicon nanowires in between, and adding a layer of stable silicon nitride on the top layer.

By etching silicon nitride and varying thickness and adjusting silicon nanowires, the team finally found the optimal combination. The final sensor successfully meets the deformation and mechanical damage while still providing a linear change in the electrical output under pressure sensing, meeting the requirements of high precision medical device applications.