Effects of Natural Aging in Biaxial MEMS Accelerometers

Abstract

Effects of a fully natural aging of MEMS accelerometers are evaluated with regard to changes in their performance. Two models of commercial dual-axis accelerometers (two pieces of ADXL 202E and 203 by Analog Devices Inc.) with analog outputs were tested over a period of about 10 and 4 years, respectively. A custom computer controlled test rig was used for performing relevant experimental studies, employing the gravitational acceleration as the reference source. A methodology of determining the proposed indicators of aging phenomena is presented and discussed. Changes of the offset voltage and the scale factor were observed and a way of evaluating the overall error due to combined influence of these two parameters is proposed. It was found out that the changes of the output voltage generated by the tested accelerometers were considerable, resulting in respective maximal errors of about 52 mg (2.6%) (ADXL 202E) or 20 mg (1%) (ADXL 203). Simple ways of reducing the effects of aging are proposed.

MEMS Inertial Sensor Calibration Technology: Current Status and Future Trends

“…From the perspective of hardware structure, the micromechanical structure of inertial sensors is mostly made of silicon. Silicon is a temperature-sensitive material, and its physical properties vary greatly with temperature, which is also an important factor causing the thermal drift of offset and the scale factor, among which the thermal drift of offset is much more dominant [20,31]. This can be handled through the application of a temperature sensor and using the average thermal characteristics (or look-up table) of a specific accelerometer model [31].…”

“…Silicon is a temperature-sensitive material, and its physical properties vary greatly with temperature, which is also an important factor causing the thermal drift of offset and the scale factor, among which the thermal drift of offset is much more dominant [20,31]. This can be handled through the application of a temperature sensor and using the average thermal characteristics (or look-up table) of a specific accelerometer model [31]. Compared with thermal drift, the long-term drift and aging effect of a silicon structure are more difficult to compensate for, and some manufacturers choose to implement models to deal with the aging effect [19].…”

Electric-Contact Tilt Sensors: A Review

“…Depending on the nature of a given application, an appropriate sensor can be selected from among the designs presented in Table 4. were observed, especially in the case of older biaxial models: the resultant errors were evaluated at even 2.6% [55]. Moreover, problems with respect to their reliability after few years of operation were reported in the case of newer triaxial acceleration sensors [56].…”

“…However, it is well known that mercury sensors are very reliable and durable, for they contain no mechanical mating elements and, being hermetically closed, are not subjected to chemical reactions (provided the electrodes are made of a proper material and thus do not react with mercury). On the other hand, what may be surprising is that in the case of MEMS accelerometers, considerable aging effects were observed, especially in the case of older biaxial models: the resultant errors were evaluated at even 2.6% [ 55 ]. Moreover, problems with respect to their reliability after few years of operation were reported in the case of newer triaxial acceleration sensors [ 56 ].…”

Long-Term Degradation Evaluation of the Mismatch of Sensitive Capacitance in MEMS Accelerometers

“…They found that the bias instability of the MEMS gyroscope increased approximately linearly with time. Luczak S. et al considered that the aging phenomenon of accelerometers could be related to four specific components: mechanical components, electric components, electronic circuits, and external electronic components [ 15 ]. However, they did not carry out a separate experiment on specific components.…”