Automated Feature Tracking for Real-Time Kinematic Analysis and Shape Estimation of Carbon Nanotube Growth

TL;DR

This paper introduces VFTrack, a real-time in-situ particle tracking framework for SEM images that automatically detects and tracks individual carbon nanotube particles, enabling dynamic growth analysis and morphology reconstruction.

Contribution

The paper presents VFTrack, a novel automated tracking system combining handcrafted and deep features, significantly improving real-time CNT growth analysis in SEM imaging.

Findings

Optimal detector-matcher combination identified (F1-score 0.78)

Enables decomposition of CNT motion into growth, drift, and oscillations

Facilitates real-time morphological reconstruction of CNT structures

Abstract

Carbon nanotubes (CNTs) are critical building blocks in nanotechnology, yet the characterization of their dynamic growth is limited by the experimental challenges in nanoscale motion measurement using scanning electron microscopy (SEM) imaging. Existing ex situ methods offer only static analysis, while in situ techniques often require manual initialization and lack continuous per-particle trajectory decomposition. We present Visual Feature Tracking (VFTrack) an in-situ real-time particle tracking framework that automatically detects and tracks individual CNT particles in SEM image sequences. VFTrack integrates handcrafted or deep feature detectors and matchers within a particle tracking framework to enable kinematic analysis of CNT micropillar growth. A systematic using 13,540 manually annotated trajectories identifies the ALIKED detector with LightGlue matcher as an optimal combination (F1-score of 0.78, $\alpha$-score of 0.89). VFTrack motion vectors decomposed into axial growth, lateral drift, and oscillations, facilitate the calculation of heterogeneous regional growth rates and the reconstruction of evolving CNT pillar morphologies. This work enables advancement in automated nano-material characterization, bridging the gap between physics-based models and experimental observation to enable real-time optimization of CNT synthesis.