On-machine separation and compensation of target mirror's surface shape errors in multidimensional interferometric measurement system.

In multi-dimensional nanopositioning and nanomeasuring devices, interference measurement is widely used. The three-dimensional (3D) target mirror serves as the spatial reference plane to achieve multidimensional interference measurements. However, the surface shape errors of the target mirror are superimposed on the geometric dimensions of the measured workpiece, which limits the system's overall measurement accuracy.

Design and experiment of multidimensional and subnanometer stage driven by spatially distributed piezoelectric ceramics.

Multidimensional microdriving stage is one of the key components to realize precision driving and high-precision positioning. To meet nanometer displacement and positioning in the fields of micro-/nano-machining and precision testing, a new six-degree-of-freedom microdriving stage (6-DOF-MDS) of multilayer spatially distributed piezoelectric ceramic actuators (PZTs) is proposed and designed. The interior of the 6-DOF-MDS is a hollow design.

Directional region-based feature point matching algorithm based on SURF.

Feature point matching is one of the fundamental tasks in binocular vision. It directly affects the accuracy and quality of 3D reconstruction. This study proposes a directional region-based feature point matching algorithm based on the SURF algorithm to improve the accuracy of feature point matching.

Development of submicron precision three-dimensional low cross-interference air-floating motion stage.

To meet the high requirements for positioning accuracy and multiple dimensions of positioning systems in the fields of precision measurement and precision machining, a new submicron-precision three-dimensional (3D) low cross-interference positioning system is designed and fabricated in this paper. The 3D motion stage mainly includes a mechanical structure, a support and guide system, and a driving system. The Abbe offset error is eliminated by adopting a coplanar structure in the X and Y directions, thus minimizing the mutual cross-interference of the motion stage.

A novel uncertainty evaluation method based on the particle filter and beta distribution for data with unknown distribution.

Uncertainty evaluation for unknown distribution data is a key problem to be solved in uncertainty evaluation theory. To evaluate the measurement uncertainty of data with unknown distributions, a novel uncertainty evaluation method based on the particle filter (PF) and beta distribution is proposed in this paper. A beta distribution with wide adaptability was adopted as the distribution type of measurement results, the parameters of the beta distribution were taken as the parameters to be estimated, and a state-space model was established.

Large-scale and high-depth three dimensional scanning measurement system and algorithm optimization.

Tapping scanning mode is an important method for measuring surface topography at the nanometer scale. It is widely used because it can eliminate lateral force and reduce damage to the tested sample. Research on three dimensional (3D) scanning technology with a large range and high depth-to-width ratio has important practical significance and engineering application value because the current scanning probe microscope has the limitations of small measurement ranges and weak Z-direction measurement ability.

High-Precision Fabrication of Micro Monolithic Tungsten Ball Tips via Arc Discharge and the Taguchi Method.

A micro ball tip is a core component of high precision coordinate measuring machines. The present micro ball tips cannot satisfy the high-precision measuring requirements of high aspect ratio microstructures due to their large diameter and low accuracy. In the previous study, we fabricated a micro monolithic tungsten ball tip by using arc discharge and surface tension principles.

Independent driving method for significant hysteresis reduction of piezoelectric stack actuators.

Piezoelectric actuators are used extensively in precision positioning platforms. However, the positioning accuracy is severely affected by the hysteresis characteristics of piezoelectric ceramics. Piezoelectric stack actuators (PSAs) are usually composed of hundreds of thin piezoelectric ceramic layers connected in parallel, and their hysteresis quantity is the accumulation of that in each layer, which results in large nonlinear deformation.

A method to correct hysteresis of scanning probe microscope images based on a sinusoidal model.

Piezoelectric actuators are widely used in scanning platforms of scanning probe microscopes (SPMs). However, the hysteresis of piezoelectric actuators reduces positioning accuracy and results in distorted SPM images. When regular raster scanning of SPM starts, the piezoelectric actuators move repeatedly at the same scanning range and frequency once the scanning parameters are set.

Development of a Micro/Nano Probing System Using Double Elastic Mechanisms.

To meet the requirement of high precision measurement of coordinate measurement machine system, a compact microprobe has been designed for 3D measurement in this paper. Aiming to reduce the influences of signal coupling during the probing process, the probe has been designed by adopting two elastic mechanisms, in which the horizontal and vertical motions of the probe tip can be separated by differential signals of quadrant photodetectors in each elastic mechanism. A connecting rod has been designed to transfer the displacement of the probe tip in vertical direction from lower to upper elastic mechanisms.

Fabrication and Study of Micro Monolithic Tungsten Ball Tips for Micro/Nano-CMM Probes.

Micro ball tips with high precision, small diameter, and high stiffness stems are required to measure microstructures with high aspect ratio. Existing ball tips cannot meet such demands because of their weak qualities. This study used an arc-discharge melting method to fabricate a micro monolithic tungsten ball tip on a tungsten stylus.

Squeeze Film Air Damping in Tapping Mode Atomic Force Microscopy.

In dynamic plowing lithography, the sample surface is indented using a vibrating tip in tapping mode atomic force microscopy. During writing, the gap between the cantilever and the sample surface is very small, usually on the order of micrometers. High vibration frequency and small distance induce squeeze film air damping from the air in the gap.

A Scanning Probe Microscope for Surface Measurement in Nano-Scale.

A tapping mode scanning probe microscopy (TM SPM) system for surface measurement in nanoscale is developed, of which the main element is a scanning probe consisting of quartz tuning fork and a long sharp tungsten tip. Quartz tuning fork is a very good resonant element with piezoelectrical characteristic, and it acts as an actuator and a force sensor simultaneously in the probe. The vertical spatial resolution of the TM SPM is up to sub-nanometer (0.

Fabrication of an Optical Fiber Micro-Sphere with a Diameter of Several Tens of Micrometers.

A new method to fabricate an integrated optical fiber micro-sphere with a diameter within 100 µm, based on the optical fiber tapering technique and the Taguchi method is proposed. Using a 125 µm diameter single-mode (SM) optical fiber, an optical fiber taper with a cone angle is formed with the tapering technique, and the fabrication optimization of a micro-sphere with a diameter of less than 100 µm is achieved using the Taguchi method. The optimum combination of process factors levels is obtained, and the signal-to-noise ratio (SNR) of three quality evaluation parameters and the significance of each process factors influencing them are selected as the two standards.

Removing nonlinearity of a homodyne interferometer by adjusting the gains of its quadrature detector systems.

Most homodyne interferometers have a quadrature detector system that includes two polarizing beam splitters that cause nonlinearity of the order of a few nanometers by phase mixing. Detectors should have the same gains to reduce nonlinearity under the assumption that there is no loss in optical components. However, optical components exhibit some loss.