Abstract:  Any movement in the modern world, whether personal (implants for disabled or elderly), device-aided (cars and satellites), or entertaining (gaming platforms and smartphones) depends on inertial microelectromechanical systems (MEMS), inevitably making them essential for our daily lives. The high precision MEMS gyroscopes may eventually enable self‐contained, autonomous navigation when signals from Global Positioning System (GPS) satellites are not available. While sub-degree per hour bias instability have been demonstrated for few microgyroscope prototypes, the current challenge is to achieve long-term stability and understand fundamental sources of bias and scale-factor drifts. In this presentation we will report long-term bias drift compensation in high-quality (Q) factor MEMS gyroscopes using real-time temperature self-sensing. The approach takes advantage of linear temperature dependence of the drive-mode resonant frequency for self-compensation of temperature-induced sense-mode drifts. The approach was validated by a vacuum packaged silicon quadruple mass gyroscope, with signal-to-noise ratio (SNR) enhanced by isotopic Q-factors of 1.2 million. Owing to high Q-factors, a measured frequency stability of 0.01 ppm provided a temperature self-sensing precision of 0.0004 degrees Celsius, on par with the state-of-the-art MEMS resonant thermometers. Real-time self-compensation yielded a total bias error of 0.5 deg/hr and total scale-factor error of 700 ppm over temperature variations. This enabled repeatable long-term rate measurements required for MEMS gyrocompassing and north-finding with a milliradian azimuth precision, providing a path for inertial-grade MEMS gyroscopes.

Bio:  Igor P. Prikhodko received the B.S. and M.S. degrees (cum laude) in applied mathematics and mechanics from the Moscow State University, Moscow, Russia, in 2007, and the M.S. degree in mechanical and aerospace engineering from the University of California, Irvine, in 2008. Currently, he is working towards the Ph.D. degree at the MicroSystems Laboratory, University of California, Irvine. His primary research focus is full-cycle research and development of inertial micromachined sensors, reflected in 4 journal and 16 international conference papers. He is a recipient of the 2008 Holmes Fellowship Award, the 2011 Outstanding Paper Award at the Transducers conference, and the 2012 Best Paper Award at the IMAPS Device Packaging conference. He is a member of the Institute of Electrical and Electronics Engineers (IEEE), the American Society of Mechanical Engineers (ASME), and serves as a reviewer for major MEMS journals.

Host:  Kimberly Turner