Understanding molecular materials remains one of the key challenges in modern materials science. Resolving the true structure–property relationships in advanced systems and nanodevices increasingly requires higher resolution and multimodal datasets, often pushing conventional approaches to their limits. Moreover, many modern functional materials are based on organic compounds that can be easily damaged by the electron beam used in the transmission electron microscope. Addressing these challenges demands the development of specialized data acquisition strategies and advanced technologies that preserve structural integrity while extracting meaningful insight.
Such progress, however, rarely happens in isolation. Moving instrumentation and applications forward requires close collaboration between academia and industry and it is built on shared questions, tested ideas, and continuous exchange of expertise.
A great example of such collaboration is the ongoing work between Tescan and Professor Andy Brown and his team from the University of Leeds. As one of the key partners in the development of the TENSOR microscope and analytical 4D-STEM techniques, they have contributed significantly to advancing new solutions for the analysis of beam-sensitive samples in materials science and to the shaping of next-generation workflows and applications.
At the University of Leeds, Professor Brown balances several roles. Alongside his teaching responsibilities, he contributes to microscope and technique development within a multi-user electron microscopy facility, supporting a broad range of users in their research.
“The samples vary from steel, cement, and plastics to very challenging biological specimens. We help users acquire meaningful data and achieve the best possible results,” he notes.
Professor Brown’s own research is focused on the characterization of nanoparticles and organic compounds. His group studies complex hybrid materials – systems that combine organic and inorganic components – exploring how their internal organization influences material behavior and performance in practical applications. Examples include pharmaceutical drugs, healthcare-related products, and chemical delivery materials.
During his recent visit to Tescan, we took the opportunity to ask Professor Brown to share his perspective on the challenges of beam-sensitive samples, how TENSOR supports his research, and how new technologies are shaping the future of materials science.
For Professor Brown, electron microscopy is fascinating because it reveals how materials are organized from the atomic scale through to larger structural arrangements, and how this organization shapes material properties.
“Defects in microstructure or subtle variations in packing can have a profound impact on material properties such as diffusion, mechanical strength, electrical conductivity or magnetism,“ he points out, highlighting the importance of understanding the structure of materials at every level.
Studying beam-sensitive or complex materials, however, comes with significant challenges. The goal is always to reveal the true structure of a sample, but getting there is far from trivial. Researchers must work within the constraints of the microscope vacuum, prepare samples that are thin enough for electrons to pass through, and at the same time ensure that the electron beam itself does not alter the structure being analyzed.
“When you consider all of those factors together,” Professor Brown notes, “the chances of getting it right can be quite challenging. If it is not properly addressed, there is a real risk of analyzing artefacts rather than the material itself, which can result in misleading conclusions.”
To avoid this, his work relies on careful validation. Results are checked against bulk techniques, and significant attention is paid to sample preparation and exposure conditions to minimize dehydration, over-thinning, or beam-induced damage. Experience plays a crucial role here.
“Scientists often aim to remove the influence of the human factor,“ Professor Brown adds. “But judgement and expertise remain essential in recognizing potential risks and accounting for them.“
Professor Brown’s interest in instruments like TENSOR emerged with the development of 4D-STEM, and the realization that collecting a diffraction pattern at every pixel makes far more efficient use of the electron dose. By capturing almost every electron that passes through the sample, researchers can extract significantly more information while minimizing beam damage - a critical advantage when working with beam-sensitive molecular compounds.
“It opens the door to a wide range of analyses,“ he explains. “You can examine molecular packing with a spatial resolution of just a few nanometers. This provides detailed insight into surface layers or interfaces, and into the changes that may occur through a system.“
What further set TENSOR apart was the combination of its flexibility and speed. The fast direct electron detector enables low-dose operation, while the platform allows users to switch seamlessly between imaging, diffraction, and compositional analysis within a single experiment.
“We can now design and refine experiments directly in the microscope, reducing time on the instrument and improving overall efficiency,“ Professor Brown explains from a user’s perspective.
Beyond workflow improvements, TENSOR enables new types of analysis that are difficult to achieve with conventional TEM or STEM approaches. This is illustrated by the study of defect structures in organic molecular crystals, where spatially resolved diffraction allowed Professor Brown’s team to resolve subtle faults in molecular packing that can influence mechanical, thermal, and diffusion-related properties.
As research in materials science is increasingly focusing on more complex and beam-sensitive systems, low-dose and cryogenic electron microscopy are set to play an important role in the near future. According to Professor Brown, cryo-STEM is already a clear growth area, offering new possibilities for how and where electron microscopy can be applied.
The ability to scan a sample, pause the probe, and analyze a specific region by diffraction and elemental spectroscopy is becoming particularly valuable. When combined with cryogenic conditions - either cooling a sample to extend its lifetime or working with frozen-hydrated specimens - researchers can study materials in their native state.
“That is a big step forward,” Professor Brown notes, “and it allows us to extend the applications far beyond traditional materials such as metals, ceramics, or semiconductors.”
It means that researchers can gradually move from hydrated crystals to organically coated systems, and ultimately to fully organic molecular materials - an area where cryogenic techniques are expected to be essential.
“In this context, TENSOR provides the capabilities needed to gain a deep understanding of the structure and chemistry at the nanometer scale,” Professor Brown adds, highlighting its flexibility in imaging, spatially resolved scanning electron diffraction, and compositional analysis.
When reflecting on a memorable lesson that continues to shape his approach to research, Professor Brown’s answer is thoughtful and personal. “Good science requires good teamwork,” he says.
For him, research is not only about results, but about the people behind them – the collaborations built over time, and the friendships that naturally grow from the established connections.
This perspective also defines his work with Tescan, which he describes as a genuinely two-way process built on open dialogue and continuous feedback. By sharing how technology is used in practice and by learning from each other’s perspectives, both teams contribute together to refining workflows and advancing research on beam-sensitive materials.