Open-source software streamlines 2D materials research through scanning tunneling microscope automation

New open-source software developed by Monash University researcher Julian Ceddia aims to dramatically streamline the study of materials using scanning tunneling microscopes (STMs).

The software, named Scanbot, automates the time-consuming processes of probe optimization and data acquisition essential to STM experiments, helping to accelerate 2D materials research by enabling detailed study after the STM tip has been automatically optimized and sharpened.

“We hope that Scanbot will benefit STM labs around the world and represent a significant step towards the full automation of STM experiments,” says Assistant Professor Agustin Schiffrin, also at Monash.

Transforming Materials Research with STM Automation

Exploring and characterizing the atomic landscape of surfaces has become a fundamental activity of modern science. STMs are among the most powerful tools that allow scientists to probe and interact with the world at this unimaginable scale, providing images and spectroscopic data that allow us to peer into the quantum realm and see how materials behave at the atomic level.

STMs work by scanning a probe, fine-tuned down to a single atom, across the surface of a material while monitoring an electrical current. This current carries all the information needed to build atomic-scale images of the surface.

However, achieving such stunning images is no easy feat. A probe that is cut to the size of a single atom is extremely fragile, and even the slightest contact with another atom, molecule, or piece of debris can drastically alter the probe’s effectiveness, requiring researchers to spend considerable time optimizing the instrument to ensure it captures reliable, high-quality data.

Scanbot Presentation

Researchers at Monash University, led by Julian Ceddia, have developed a reliable way to automate this STM optimization process, resulting in the creation of Scanbot, a freely available open-source software package.

The research paper is published in the Free Software Journal.

Ceddia explains that an epiphany came to him after he grew tired of spending hours optimizing and sharpening the STM tip to obtain meaningful data. “After countless hours of refining the STM during my PhD, I discovered that the quality of the probe could be easily quantified by visualizing the imprints it leaves after being pushed a few angstroms into the surface.”

These fingerprints contain information about the arrangement of atoms at the tip of the scanning probe and are essential for predicting data quality before acquiring it. “Basically, sharper tips leave smaller fingerprints, so Scanbot automates the process by repeatedly pressing the tip against the surface until the fingerprint shows that the tip is sharp enough for high-quality imaging,” Ceddia explains.

This simple “tip shaping” approach avoids many of the problems associated with using machine learning for similar tasks. “Instead of training an AI on vast amounts of labeled data to recognize high-quality images, Scanbot uses simple algorithms to measure the size and symmetry of the probe’s apex based on the footprints it leaves,” adds Dr. Benjamin Lowe, one of the project’s lead collaborators.

But Scanbot’s capabilities go beyond simple tip shaping. It also automates common data acquisition techniques, such as sampling, making STMs easier to use overall. “My goal with Scanbot was to make STMs more accessible and user-friendly,” Ceddia says. “That’s why I invested a lot of time in designing an intuitive user interface and writing comprehensive documentation.”

Industry Recognition and Impact

Scanbot’s potential has been aptly described by Jack Hellerstedt, a former Monash University researcher who also made significant contributions to the project: “Scanbot has the heretical potential to get budding surface scientists thinking about the data instead of clicking the button.”

The industry has already taken notice of Scanbot’s capabilities. SPECS, a leading company in the field of STM systems control, recently contacted Ceddia after discovering Scanbot.

“Receiving an email from SPECS asking to include links to Scanbot in their documentation was incredibly encouraging,” Ceddia recalls. “It clearly shows that our work can really make a difference in how STMs are operated.”