On cross-talk between gyroscopes integrated on a folded MEMS IMU Cube

This paper reports a miniature Inertial Measurement Unit (IMU) implemented using a folded MEMS approach which allows for integration of high performance sensors, while providing a low cross-talk between the components. Foldable Si structures are manufactured on a wafer-level using MEMS techniques, co-fabricated or integrated with single-axis inertial sensors and then folded into a 3D configuration, forming the complete IMU. Electrical signals from the sensors on sidewalls of the IMU Cube are transferred through the dense network of metal traces on parylene, thus enabling the integration with signal processing electronics. For the first time, we characterized cross-talk between sensors on a folded 3D IMU. The experimental results provided an evidence that the folded IMU process is advantageous to a single-die approach, showing a lower Angle Random Walk (ARW) of the gyroscopes when operated simultaneously on different sidewalls of the IMU Cube.