Gong, XuewenXuewenGongWEN-JONG WULiao, Wei HsinWei HsinLiao2023-07-172023-07-172020-01-0197815106353570277786Xhttps://scholars.lib.ntu.edu.tw/handle/123456789/633756Prognostics and health management (PHM) is a crucial measure to minimize the financial loss caused by downtime and damage in smart factories. To prevent the failures of industrial machines, a low-noise three-axis piezoelectric accelerometer in small scale is proposed to measure the vibration parameters for PHM application. It consists of a middle tungsten proof mass and 4 composite beams, which includes PZT and stainless steel layers. Simulation validates the principle of 3-axis measurement and gives the sensitivities of 0.714 mV/g, 0.714 mV/g and 1.72 mV/g for x-, y- and zaxis sensing. Calculated mechanical-thermal noise is 0.4 μg/√Hz, much lower than the typical noise of a commercial capacitive MEMS accelerometer. The designed sensor is fabricated with a metal-MEMS process and aerosol deposition method with the resonant frequency around 4.11 kHz. The testing results of x- and y-axis sensitivities, 0.5541 mV/g and 0.5420 mV/g, show the effectiveness of dual-axis measurement. In the end, the study analyzes hypotheses for the coupling of 3-axis measurement and proposes the improvement direction in further study.Aerosol deposition | Low noise | MEMS piezoelectric | Three-axis accelerometer[SDGs]SDG3[SDGs]SDG9conference paper10.1117/12.25590212-s2.0-85085680850https://api.elsevier.com/content/abstract/scopus_id/85085680850