Improved Control Strategies for Intermittent Contact Mode Atomic Force Microscopes

TL;DR

This paper presents three advanced control strategies for intermittent contact mode atomic force microscopes that improve image quality, reduce artifacts, and adapt scan speed in real time, enhancing performance on soft samples.

Contribution

Introduction of three novel control approaches for AFM that eliminate artifacts, adapt scan speed, and predict sample features in real time.

Findings

Enhanced image quality with fewer artifacts

Automatic scan speed adaptation improves efficiency

Real-time feature prediction enhances imaging accuracy

Abstract

Atomic force microscopes have proved to be fundamental research tools in many situations where a gentle imaging process is required, and in a variety of environmental conditions, such as the study of biological samples. Among the possible modes of operation, intermittent contact mode is one that causes less wear to both the sample and the instrument; therefore, it is ideal when imaging soft samples. However, intermittent contact mode is not particularly fast when compared to other imaging strategies. In this paper, we introduce three enhanced control approaches, applied at both the dither and z-axis piezos, to address the limitations of existing control schemes. Our proposed strategies are able to eliminate different image artefacts, automatically adapt scan speed to the sample being scanned and predict its features in real time. The result is that both the image quality and the scan time are improved.