Providing a multiscale view on materials

After a major technical upgrade, in May 2023 the Center for Multiscale Electron Microscopy was reopened with a celebratory ceremony. ‘We had been running before under difference names for about twenty years’, says Heiner Friedrich, ‘facilitating materials research, both from a fundamental and an applied perspective.’ The lab welcomes TU/e researchers from all departments, and occasionally also accommodates industrial research.

The Center is primarily known for three areas of expertise, Friedrich explains: ‘We operate a cryo-electron microscope for soft matter and polymer research, electron microscopes capable of in situ studies where materials can be placed  in more realistic liquid or gaseous environments, including exposure to external stimuli, and 3D electron microscopy to gain quantitative insights into the 3D organization of materials from the nanometer scale to tens of micrometers.’

Zooming in on graphene
Besides leading CMEM, Friedrich is deeply involved in material research himself. ‘Currently, I am studying the direct usage of graphene for different applications. For example, I am working on a project that is a part of the EU Graphene Flagship initiative where we are investigating graphene based printable electronics.’ Besides its electrical conductivity, graphene is also known for its high heat conductivity, which makes it an interesting material in the context of the energy transition, he explains. ‘At the moment, in the WAX+ project we are looking at the possibilities of using graphene to improve the thermal conductivity of cheap, non-toxic, and stable technical grade paraffins for heat storage applications.’

With the facilities at CMEM, researchers can study materials from the nanometer scale to tens of micrometers and with (sub)nanometer resolution. ‘To find a meaningful way to adjust a material’s multiscale morphology, you need to understand what is in between the atomic level and the scale of application,’ Friedrich states. The Center’s facilities are the eyes of the scientists who for example want to follow how catalysts age, what membranes or electrolyzers look like at the smallest scales, or how salt(hydrates) used for heat batteries might change after several charging and discharging cycles.

From cells to concrete
At the moment the Center has some 200 users, its head says with pride. ‘We have colleagues from ICMS working on polymers, colleagues from biomedical engineering working on cellular materials, and even colleagues from the built environment who are trying to improve concrete. With our tracks directed toward energy, healthcare, and sustainability, we are covering a large range of TU/e research.’

Any researcher who wants to make use of the facilities is free to send a request to cmem@tue.nl. ‘We will then send them an intake form to be filled in, detailing the topic of research and the planned experiments. With that information we can assess whether or not our lab is the most suitable one to conduct the experiments and discuss what instrument to use and what training is required,’ Friedrich explains the procedure.

Do it yourself
Training? One might wonder. Indeed. Though CMEM has several research technicians, Friedrich prefers for the users to conduct their experiments themselves. ‘If someone wants to use our facilities for a longer period, we typically train them to use the electron microscopes on their own. I find that if researchers carry out the work themselves that leads to optimal results, since no one knows better what to look for in the images.’

In the meantime, the Center’s research technicians are working on optimizing sample preparation and imaging workflows and training users. ‘Of course there are some standards, for example on how to prepare aqueous dispersions for cryoTEM analysis, but in organic solvents there are not that many labs capable of conducting such experiments. For those kinds of unique requests, we develop dedicate workflows ourselves.’

Meeting of the Dutch electron microscopy community (NEMI day 2023) at TU Eindhoven.

One stop shop
‘In Eindhoven, we are in the front row when it comes to electron microscopy’, Friedrich emphasizes, ‘with Thermo Fisher right around the corner. And since electron microscopy is on the university’s infrastructure roadmap, the threshold for using our facilities is kept low. What’s more, we are also a Flagship node of the Netherlands Electron Microscopy Infrastructure (NEMI) and we recently organized the NEMI day here at TU/e. So, if you need to make use of an electron microscope, please feel free to contact us and together with you we will find the best solution, whether within CMEM or somewhere else in the Netherlands.’