A high-performance multi-beam microaccelerometer for vibration monitoring in intelligent manufacturing equipment

A piezoresistive microaccelerometer with multi-beam structure is developed for vibration monitoring in intelligent manufacturing equipment. The proposed accelerometer provides a promising solution to the trade-off between the cost-effective development and demands on high-performance sensors. By incorporating tiny sensing beams, the multi-beam accelerometer obtains a higher resonant frequency and favorable measurement sensitivity compared with the quad-beam one. Theoretical analysis and finite element method (FEM) simulation demonstrate satisfactory results of an improved resonant frequency increased by a factor of 1.81 at the expense of slight sensitivity loss. Fabricated on an n-type single crystal silicon wafer, the sensor chips with multi-beam structure and quad-beam structure are wire-bonded to printed circuit boards (PCBs) and simply packaged for experiments. The static and dynamic characteristics of the two types of sensors are tested and compared. The temperature coefficient of offset output is also measured. The results show that the developed accelerometer has favorable features that allow its usage in the demanding application.

► The multi-beam structure for piezoresistive accelerometers is proposed, modeled and simulated.
► The resonant frequency of the sensor is enhanced and the sensitivity is competitive.
► The multi-beam accelerometer and contrastive quad-beam accelerometer are fabricated and tested.
► Available range of the length sensing beam in multi-beam structure is investigated.