MEMS Nanopositioner for On-Chip Atomic Force Microscopy: A Serial Kinematic Design

Abstract

The design and characterization of a twodegree-of-freedom serial kinematic microelectromechanical systems (MEMS) nanopositioner for on-chip atomic force microscopy (AFM) is reported. A novel design is introduced to achieve a serial kinematic mechanism based on a standard siliconon-insulator MEMS fabrication process. The nanopositioner comprises a slow axis with a resonance frequency of 2.4 kHz and a fast axis with a resonance frequency of above 4.4 kHz, making it ideal for rastering, as required in the AFM. Strokes of 14 and 9 µm are experimentally achieved for the fast and slow axes, respectively. The serial kinematic design of the stage enables the cross-coupling between the two axes of motion to be as low as −60 dB. Electrothermal displacement sensors are incorporated in the device, which may be used to enable feedback control as required in high-speed AFM. [2014-0248]Index Terms-Nanopositioner, MEMS, atomic force microscopy, serial kinematic mechanism.

On-Chip Dynamic Mode Atomic Force Microscopy: A Silicon-on-Insulator MEMS Approach

“…In addition, these beams have a smaller form factor compared to the folded flexures, leading to a more compact structure in this direction. The incorporated mechanical suspension systems in both axes are designed to prevent the occurrence of snap-in within the electrostatic actuators by providing sufficient longitudinal stiffness throughout the entire range of displacement and actuation voltages [11].…”