Simulation and experimental verification of nanoscale motion in a 2-axis quasi-passive platform

Abstract

As leading edge technology pursues a common trend of working on smaller and smaller scales, there is increasing demand on motion management at the nanometer range. We previously reported a 1-axis quasi-passive platform with nanoscale alignment tolerance (Li et al 2005 J. Microelectromech. Syst. 14 1339–46). This paper presents our research on a 2-axis positioning platform capable of four degrees-of-freedom in-plane motion. The concept comprises a platform suspended by tensile stressed flexure elements on either side. Finite-element simulation shows that translation is achieved by cutting pairs of stress elements that are symmetrical to the x- or y-axis (axis-symmetrically cut), while angular motion is achieved by cutting pairs of stress elements that are symmetrical to the center point of the platform (center-point-symmetrically cut). Focused ion beam experiments demonstrate that such a platform enables positioning accuracy in the order of tens of nanometers. Variable-temperature scanning electron microscopy demonstrates that temperature variation modifies the platform position at a rate of 0.81 nm °C−1 for a platform with only three support stress elements at each side. Finally, we have performed fiber coupling experiments using an automated control program, and have demonstrated optimized coupling efficiency using the 2-axis device.