Related Experiment Video
Updated: Oct 20, 2025
07:32
Measurement of Vibration Detection Threshold and Tactile Spatial Acuity in Human Subjects
Published on: September 1, 2016
12.9K
OBSERVER-BASED CONTROL OF A DUAL-STAGE PIEZOELECTRIC SCANNER
Yuhe Chang1, Sean B Andersson2
1Department of Mechanical Engineering, Boston University, Boston, Massachusetts 02215.
Proceedings of the ASME Dynamic Systems and Control Conference. ASME Dynamic Systems and Control Conference
|September 10, 2021
Summary
This study introduces a new scanning algorithm, Local Circular Scan (LCS), for atomic force microscopy (AFM). LCS significantly speeds up imaging by scanning less, making it ideal for enhancing older AFM instruments.
Area of Science:
- Surface Science
- Microscopy Technology
- Control Systems Engineering
Background:
- Atomic Force Microscopy (AFM) is a powerful imaging technique limited by slow scan speeds.
- Algorithmic approaches that reduce data acquisition by scanning less offer a path to faster imaging.
- Combining advanced scanning hardware with intelligent algorithms can further boost imaging rates.
Purpose of the Study:
- To develop and validate a novel scanning strategy for AFM to overcome imaging speed limitations.
- To integrate the Local Circular Scan (LCS) algorithm with a dual-stage piezoelectric scanner.
- To establish a robust control framework for the multi-input, single-output scanning system.
Main Methods:
- Implementation of the Local Circular Scan (LCS) algorithm, which uses circular trajectories centered on sample features.
- Utilizing a dual-stage piezoelectric scanner for high-frequency circular motion and slower linear tracking.
- Applying the principle of separation to design individual controllers for short-range and long-range actuators.
- Employing an internal model controller for circular path generation and a state-space controller for feature tracking.
Main Results:
- Controllability and observability of the dual-stage scanning system were established.
- Individualized controllers were successfully designed for precise control of both scanning stages.
- Simulations demonstrated the feasibility of the LCS algorithm with the dual-stage scanner for reduced imaging time.
Conclusions:
- The Local Circular Scan (LCS) algorithm, when coupled with a dual-stage piezoelectric scanner and appropriate control, offers a viable method to significantly enhance AFM imaging rates.
- This approach provides substantial improvements, particularly for instruments with existing hardware limitations.
- The developed control strategy ensures accurate tracking of both circular scanning paths and linear movement along sample features.
