An improved structural design for accelerometers based on cantilever beam-mass structure

Purpose - The purpose of this paper is to provide an improved structural design for accelerometers based on cantilever beam-mass structure and offer the descriptions of sensor fabrication, packaging and experiments. Design/methodology/approach - The cantilever beam-membrane (CB-membrane) structure is designed as the sensing element for piezoresistive accelerometers. In the CB-membrane structure, a cantilever beam and two identical membranes as a whole part supports the proof mass. Four piezoresistors are distributed on the surface of the cantilever beam to form a Wheatstone bridge. Finite element method is used to carry out the structural analysis and determine the sensor dimensions. The sensor chip is fabricated by bulk micro-machining technique, packaged in dual-in-line (DIP) way and tested. Findings - Compared with the conventional cantilever beam-mass (CB-mass) structure, the CB-membrane structure can improve the sensor's performances, including response frequency, output linearity and cross-axis sensitivity. The results of simulation and experiments prove that the CB-membrane accelerometer has good performances. Research limitations/implications - The accelerometer is simply packaged and the zero offset voltage has not been compensated. Moreover, the measured response frequency is lower than the simulated value. Further work and study are needed to solve these problems. Originality/value - The accelerometer with CB-membrane structure has good performances as the static and dynamic experiments show and is suitable to detect the spindle vibration of the machine tools.