Characterization and Benchmark of a Novel Capacitive and Fluidic Inclination Sensor

Abstract

In this paper, a fluidic capacitive inclination sensor is presented and compared to three types of silicon-based microelectromechanical system (MEMS) accelerometers. MEMS accelerometers are commonly used for tilt measurement. They can only be manufactured by large companies with clean-room technology due to the high requirements during assembly. In contrast, the fluidic sensor can be produced by small- and medium-sized enterprises (SMEs) as well, since only surface mount technologies (SMT) are required. Three different variants of the fluidic sensor were investigated. Two variants using stacked printed circuit boards (PCBs) and one variant with 3D-molded interconnect devices (MIDs) to form the sensor element are presented. Allan deviation, non-repeatability, hysteresis, and offset temperature stability were measured to compare the sensors. Within the fluidic sensors, the PCB variant with two sensor cavities performed best regarding all the measurement results except non-repeatability. Regarding bias stability, white noise, which was determined from the Allan deviation, and hysteresis, the fluidic sensors outperformed the MEMS-based sensors. The accelerometer Analog Devices ADXL355 offers slightly better results regarding offset temperature stability and non-repeatability. The MEMS sensors Bosch BMA280 and TDK InvenSense MPU6500 do not match the performance of fluidic sensors in any category. Their advantages are the favorable price and the smaller package. From the investigations, it can be concluded that the fluidic sensor is competitive in the targeted price range, especially for applications with extended requirements regarding bias stability, noise, and hysteresis.

A Novel Wireless Low-Cost Inclinometer Made from Combining the Measurements of Multiple MEMS Gyroscopes and Accelerometers

“…Allan variance shows the progress of a noisy sensor signal over time which can be very useful to identifying the progressive random-walk of a gyroscope instead of ND that quantifies the noise density of an accelerometer [ 57 ]. Allan deviation is more commonly used as the square root of Allan variance [ 81 ]. The available acquired inclination acquisition data for measuring the standard deviation of the previous subsection was used for the Allan variance and deviation calculations.…”

Multiple-Degree-of-Freedom Modeling and Simulation for Seismic-Grade Sigma–Delta MEMS Capacitive Accelerometers

“…High-end capacitive accelerometers based on microelectromechanical system (MEMS) technology are widely applied in seismometers [ 1 , 2 ], inclination measurement [ 3 ], microgravity measurement [ 4 ], inertial navigation [ 5 ], etc. A high-resolution MEMS accelerometer with a noise floor of sub-µg is commonly required for seismic-grade application [ 1 ].…”

A Study on the Harmonic Distortion of Seismic-Grade Sigma-Delta MEMS Accelerometers Using a Multiple Degree-of-Freedom Model

“…High-end capacitive accelerometers based on microelectromechanical system (MEMS) technology are widely applied in seismometers [1,2], inclination measurements [3], microgravity measurements [4], and inertial navigation [5], etc.…”