Modelling and optimization of single drive 3-axis MEMS gyroscope

Abstract

This paper presents a design optimization approach for a single-drive, 3-axis Microelectromechanical Systems (MEMS) gyroscope. Mathematical models for springs are obtained and a simplified structure for single-drive, 3-axis MEMS gyroscope is proposed. In the proposed structure, concentrated spring architecture was exploited to critical mechanical elements in order to mitigate the fabrication imperfections in the design and the effect of unwanted frequencies. The number of elastic elements was also reduced, while increasing the active area efficiently. The proposed simplified, single-drive, 3-axis MEMS gyroscope is using mode split approach, having a drive resonant frequency of $$25443\mathrm{H}\mathrm{z},$$ with the $$x-\mathrm{s}\mathrm{e}\mathrm{n}\mathrm{s}\mathrm{e}, y-\mathrm{s}\mathrm{e}\mathrm{n}\mathrm{s}\mathrm{e}, \mathrm{a}\mathrm{n}\mathrm{d}\mathrm\ z-\mathrm{s}\mathrm{e}\mathrm{n}\mathrm{s}\mathrm{e}$$ being $$25529\mathrm{H}\mathrm{z}$$ , $$25612\mathrm{H}\mathrm{z}$$ , and $$25621\mathrm{H}\mathrm{z},$$ respectively. The drive and desired sense resonant frequencies are separated by a frequency difference of less than 300 $$\mathrm{H}\mathrm{z}$$ , while the unwanted ones are above $$3 \mathrm{k}\mathrm{H}\mathrm{z}$$ .