Mapping Intrinsic Electromechanical Responses at the Nanoscale via Sequential Excitation Scanning Probe Microscopy Empowered by Deep Data

TL;DR

This paper introduces a deep data methodology combined with sequential excitation scanning probe microscopy to efficiently and accurately map intrinsic electromechanical responses at the nanoscale, overcoming limitations of traditional analysis methods.

Contribution

It presents a novel integrated approach using SE-SPM, SHO modeling, and PCA for high-fidelity nanoscale property mapping with enhanced speed and physical interpretability.

Findings

High-quality data acquisition with SE-SPM on standard AFM

Four orders of magnitude speed-up in analysis via PCA

Successful mapping of intrinsic electromechanical properties

Abstract

Ever increasing hardware capabilities and computation powers have made acquisition and analysis of big scientific data at the nanoscale routine, though much of the data acquired often turns out to be redundant, noisy, and/or irrelevant to the problems of interests, and it remains nontrivial to draw clear mechanistic insights from pure data analytics. In this work, we use scanning probe microscopy (SPM) as an example to demonstrate deep data methodology, transitioning from brute force analytics such as data mining, correlation analysis, and unsupervised classification to informed and/or targeted causative data analytics built on sound physical understanding. Three key ingredients of such deep data analytics are presented. A sequential excitation scanning probe microscopy (SE-SPM) technique is first adopted to acquire high quality, efficient, and physically relevant data, which can be easily implemented on any standard atomic force microscope (AFM). Brute force physical analysis is then carried out using simple harmonic oscillator (SHO) model, enabling us to derive intrinsic electromechanical coupling of interests. Finally, principal component analysis (PCA) is carried out, which not only speeds up the analysis by four orders of magnitude, but also allows a clear physical interpretation of its modes in combination with SHO analysis. A rough piezoelectric material has been probed using such strategy, enabling us to map its intrinsic electromechanical properties at the nanoscale with high fidelity, where conventional methods fail. The SE in combination with deep data methodology can be easily adapted for other SPM techniques to probe a wide range of functional phenomena at the nanoscale.