Experimental study of a low-g micromachined electrostatically suspended accelerometer for space applications

Self-Locking Avoidance and Stiffness Compensation of a Three-Axis Micromachined Electrostatically Suspended Accelerometer

“…A total of forty vertical stop blocks and eight lateral stop blocks are fabricated to restrict the PM’s range of motion and prevent possible contacting between the PM and the surrounding electrodes, as well as to effectively overcome the potential adhesion problem. The MESA device is fabricated with bulk micromachining based on the silicon on glass (SOG) technique [ 17 , 21 ]. To maintain stable suspension, the motion of the PM in all six DoFs, i.e.…”

“…However, the traditional ESAs are mainly restricted in a few space applications [ 5 , 6 ] because of their large size, complicated fabrication techniques, and extremely high cost. Recently, several micromachined electrostatically-suspended accelerometers (MESAs) have been reported based on micro-electrical-mechanical system (MEMS) technologies [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. MEMS-based fabrication can dramatically reduce the size and cost, and expand potential application possibilities.…”

“…Thus, the performance of a MESA device can be customized by different designs of the electrostatic suspension [ 18 ]. The PM of a MESA is typically suspended in the geometric center of the stator electrode cavity in six degrees of freedom (DoFs), which means the MESA has the ability to sense linear acceleration along three mutually-orthogonal axes [ 16 , 17 , 18 ]. Currently, the commercialized three-component (3C) geophones in land seismic sensing [ 19 , 20 ], such as DSU3 from Sercel (Carquefou Cedex, France) and SF3600 from Colibrys (Yverdon-les-Bains, Switzerland), utilize three single-axis accelerometers and position their sensitive axes in a mutually-orthogonal configuration, which will result in a bulky package.…”

“…Among these techniques, one of the most challenging is position detection and levitation control of the PM in multiple DoFs. Currently, there are several reports on electrostatic suspension of the MESA with active control method, such as three-axis suspension of a spherical PM [ 10 ], five-axis levitation of ring-shaped PMs [ 11 , 12 , 13 , 14 , 16 ], and six-axis suspension of parallelepiped PMs [ 15 , 17 , 18 ]. However, considering inherent cross-axis coupling and the negative spring effect of electrostatic suspension in this three-axis MEMS accelerometer, how to lift up the PM smoothly from the resting electrodes to its equilibrium position during initial levitation, and how to eliminate the negative spring effect during normal suspension, are two of the most challenging aspects for designing a closed-loop electrostatic suspension system in practical MESA applications.…”

Electromagnetic Suspension Acceleration Measurement Model and Experimental Analysis

“…The acceleration is measured by detecting the potential change caused by the displacement change of the mass. The measurement accuracy of the electrostatic suspension accelerometer is 10 −15 g [13], but the measurement dynamic range is small, the bandwidth is narrow, and the requirement of the applied voltage is high [14]. The proof mass of the superparamagnetic accelerometer uses superparamagnetic material, and the superparamagnetic material consists of nano-scale Fe 3 O 4 .…”