Stream LPEM system wins the Microscopy Today 2020 Innovation award

Stream LPEM system wins the Microscopy Today 2020 Innovation award

A conversation with our CTO Dr. Hugo Pérez-Garza who has been leading the development of the award winning system.

DENSsolutions is one of this year’s winners of the Microscopy Today Innovation Award. At the 2020 Microscopy & Microanalysis Virtual Meeting, DENSsolutions Stream LPEM system has been recognized as one of the ten most innovative products of the year.

We interviewed CTO Dr. Hugo Pérez- Garza to learn exactly how the Stream system convinced the jury of its high degree of innovation that makes new scientific investigations possible. Below you will find a transcript of the video interview.

Congratulations on winning the award. Can you tell us how you felt when you first heard the news?

It was great to hear that we were selected as the innovation of the year. This is something that confirms not only the level of innovation that the team has been bringing up, but it also helps us to confirm our leading position in the market. So it’s been really great.

Who were the people you first shared the news with?

As you can imagine, the first people that I shared this with were the R&D team members. As soon as I heard about this innovation award, I immediately called for a meeting so that I could tell everyone about it. None of this would have been possible without the ongoing effort of everyone within the R&D team. So they were the ones who deserved to know first. And of course, to me, it’s been a privilege to have the chance to lead what I consider as a world class R&D team.

Can you tell us about the innovative aspects that made it earn the reward?

Yes, this is all thanks to the different components that make up the Stream system. We’ve got the nano cell, the holder, our pressure based pump and of course the hardware that allows us to introduce the stimuli.

The nano-cell has a patented design that allows us to have on-chip inlet and outlet so that we can have a well-defined microfluidic path. We have the holder that has a modular design so that you can disassemble the tip at any point, do some thorough washing, you can put the tip in a sonicator, and because you can remove the tip, you can also replace the inner tubing at any point so that you can prevent cross contamination or clogging. And then we have the pump that, as opposed to current solutions that are out there which rely on a syringe pump that only pushes the liquid via the speed of the stepper motor, in our case, we can control the actual pressure of the liquid. So because we can combine this with our current nano-cell, by independently controlling pressure at the inlet and outlet, we can control the absolute pressure inside of the fluidic channel and therefore enjoy a very well-defined, pressure driven flow. And then we have the heating control unit and the potentiostat that allows us to introduce either the heating or biasing capabilities.

Why did you guys develop this system to start with?

Before the Stream system, we used to work with the so-called Ocean system, which is the predecessor of the Stream. Back in those days, we started realizing, together with our customers, that one of the most important things to address was to prevent relying on diffusion as a way of getting the liquid into the region of interest where the window and the sample is located. So after discussing a lot with experts and people in the community, we realized that it was important to make sure that we wouldn’t be bypassing the chips in the so-called bathtub design, which is the same design that not only our predecessor system used to have, but also other systems out there are still relying on. So making sure that you can prevent the bypass of the chips, making sure that you can therefore control the mass transport was something that ultimately gives you the benefit of controlling the kinetics of your experiment at any point.

What are the main benefits of the system?

Because we can control not only the pressure and the flow, there’s a lot of things that basically start from that point onwards, which are the fact that since you can control the liquid thickness, you can control, for example, the possibility of avoiding the beam broadening effects that the electron beam typically suffers from when you are working in liquid. If you can achieve that, then that means that you can start providing meaningful electron diffraction capabilities, meaningful EELS capabilities. You can do elemental mapping in liquid. And the fact that we still preserve that flow and pressure control at any point allows you also to start getting other very important benefits, such as the capability to mitigate away unwanted bubbles. You can even dissolve the bubbles at any point, or you can flush away beam induced species.

So when you put it all together, it really results in a very strong system that addresses the main issues that the community has been facing. The modular design of the Stream holder allows for flexibility as it prevents cross contamination or clogging when changing experiments. The system allows you to have a reproducible flow through your region of interest at any point. And you can manipulate the sample environment to your own convenience as you are able to control all the parameters that are around it.

Who contributed to the development of this system?

You can imagine that the Stream system was the result of a multidisciplinary work. We had to call in our main expertises in-house. We see MEMS development as our core competence. But MEMS is something that is very complex, that involves different areas. So we have people with a lot of expertise on the mechanical engineering area, on the electrical engineering area, material sciences, physics, chemistry and biology. But of course, the system, as I mentioned before, is not only the MEMS, but also the holder, the pump. So there’s a lot of mechatronics development in there. You can imagine that, of course, there’s a lot of microfluidics fluid dynamics.

So overall, it was a highly multidisciplinary work that, together with the expertise and the advice that we got from our customers, allowed us to put it all into one strong system that is now being able to address many of the issues that they all had.

Are customers already working with the system?

Yeah, absolutely. Ever since the launching of the system, by now, we have a very good amount of systems that are installed in the field where people are working in all sorts of application. Like material sciences, life sciences and energy storage. And we see that this system has been able to take over the work that they attempted to do for many years before. But due to the limitations that their previous systems had, they were never able to achieve. Now, with the Stream system we see and we hear directly from the customers that they’re finally able to start speeding up with the research and the results that they always wanted to get. So it’s a great feeling for us to know that the value is really there.

Who are the people that will benefit most from this system?

Of course, the Stream system finds its applications in a wide variety of opportunities. On one side, people in material sciences, people interested in, for example, nucleation work, in chemical production processes where it is very important not only to control the kinetics, but also to control the temperature. That’s where the Stream system finds one of its core values. On life sciences of course, people who are interested in working with either fuel cell analysis or biomolecule analysis where it is very important to try to mimic as much as possible physiological conditions like 37 degrees of body temperature. Controlling the environment and keeping these samples in its native liquid environment. That, of course, opens up a lot of opportunities for people in these kind of fields. And people who are doing research on energy storage, for example, people trying to develop the next generation of batteries where it is really important to understand how the battery works. What are the best conditions to prevent, for example, dendrite growth that might lead to short circuit. People working on fuel cells, people working on corrosion. There’s really a wide variety of electrochemical applications where the Stream also brings some big added value.

Can you tell us something about what future developments lie ahead?

Despite the fact that our current Stream system is already addressing most of the important issues that the LPEM community wants to avoid, we still remain very self-critical on our own developments and we keep analyzing what the main areas of opportunities for our system still are. And by now, we have already identified additional steps that we can take further. So we’re working very hard on new developments that I think are going to be really exciting. So stay tuned, because in the upcoming months, we can expect some very nice announcements on future developments that are coming.

Thank you for reading, to learn more about our Stream system please follow the links below.

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In-situ imaging provides detailed insights on the dynamics of SMSI induced overlayer formation on catalyst particles

In-situ imaging provides detailed insights on the dynamics of SMSI induced overlayer formation on catalyst particles

Enabled by DENSsolutions Climate system in correlation with other TEM characterization techniques

Original article by Arik Beck, Xing Huang, Luca Artiglia, Maxim Zabilskiy, Xing Wang, Przemyslaw Rzepka, Dennis Palagin, Marc-Georg Willinger & Jeroen A. van Bokhoven.

Noble metal nanoparticles stabilized on oxide supports are an important class of catalysts that are used in many applications such as fuel cells, exhaust gas treatment and energy conversion. It is well known that an interaction occurs between the nanoparticles and their oxide support which affects the catalytic activity called ‘strong metal-support interaction’ (SMSI). SMSI is a surface phenomena in which the migration of partially reduced oxide species, from the oxide support, covers the nanoparticle and thereby alters the chemisorption and catalytic properties. It can give rise to desired synergistic effects and increased selectivity. Now, using in situ TEM combined with other analytical techniques and theoretical modelling, researchers at ETH Zurich have been able to create a real time view of the SMSI phenomena.

Controlling the sample environment

Reductive pre-treatment of catalysts by heating, resulting in SMSI, has been known to alter the selectivity of oxide supported nanoparticles since the late 1970’s. However, the exact influence of the different parameters like temperature and gas concentration were still unknown. But now, thanks to the DENSsolutions Climate G+ system, researchers are able to determine the immediate effect of these parameters in increasing detail. The Climate G+ system provides a nano-reactor, containing the catalyst sample, that can be placed in any TEM* and gives the researcher unprecedented control over the sample environment in terms of temperature and gas parameters.

The in situ TEM experiments performed for this research required multiple switching between hydrogen and oxygen environments at 600 °C. This made the Climate G+ system, that is used on the JEM-ARM 300F at ETH Zurich, ideal for this research.

Evolution and dynamic structural changes of the overlayer in SMSI. A platinum particle on a titania support in the first exposure to H2 at 600 °C (a,b) and the subsequent atmosphere change to O2 at 600 °C (c), a switch to H2 (d) and then a switch to O2 again (e), and interpretation of the phenomena based on the combined results of in situ transmission electron microscopy, in situ X-ray  photoemission spectroscopy, and in situ powder X-ray diffraction (f–j). Insets for c–e show a magnified image of the overlayer structure observed. Scale bar is 5 nm.

Correlative techniques

In situ TEM, using gas and heating, is a powerful characterization technique to obtain atomistic, real time, information about the SMSI phenomena. To derive a holistic view of SMSI and the role of hydrogen and oxygen within this process. The in situ TEM results have been combined with ambient pressure XPS and in situ powder XRD experimental results. Finally, theoretical density functional theory (DFT) modelling was used to support the conclusions about how SMSI actually works.

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New article about the Stream Liquid Heating system

New article about the Stream Liquid Heating system

Published in Journal of Materials Chemistry C

Original article by J. Tijn van Omme, Hanglong Wu, Hongyu Sun, Anne France Beker, Mathilde Lemang, Ronald G. Spruit, Sai P. Maddala, Alexander Rakowski, Heiner Friedrich, Joseph P. Patterson and H. Hugo Pérez Garza.
We are proud to announce a new publication in the Journal of Materials Chemistry C, in which we collaborated with our customers to observe the temperature dependent etching behavior of silica particles inside the TEM. The paper discusses the design of the Stream system and how it allows to control the solution conditions inside the Nano-Cell. For this experiment, we were particularly interested in the comparison between in situ LPEM data and ex situ data from more traditional methods.

According to the reviewers

“In this manuscript, the authors provided a new design of MEMS based liquid flow system with a unique on-chip microfluidic channel and a microheater, which enables the quick replenishment of fresh solution and uniform heating of the liquid solution.”

Connecting in situ to ex situ

One of the most fundamental challenges that any microscopist experiences is the question whether the phenomenon you observe inside the microscope is representative of what happens outside. You can see interesting things happening inside the microscope, but if there is no link to the outside world, the knowledge is not so useful.

To solve this challenge, we design our products so that the user has full control of all the relevant parameters during the in situ experiment. In the Stream system, this relates to controlling the solution conditions. Especially temperature and concentration. The sample should experience the same conditions inside and outside the TEM. To achieve this, the Stream system has a flow channel that enables rapid replenishment of the solution to ensure continuous supply of fresh reactant species. Meanwhile, the microheater accurately controls the temperature.

Temperature control

Temperature is a highly important variable to control. For this reason, all our product lines include the possibility to manipulate temperature. In liquid, the speed of chemical reactions is often dictated by the temperature. Moreover, completely different reaction pathways can be found at different temperatures. During an in situ experiment, the increase in temperature can be used to trigger a phenomenon. Many people rely on the electron beam to induce the dynamics. However, it’s normally desirable to decouple the stimulus from the imaging. In other words, the beam is used for imaging, while the MEMS device supplies the heat to start a reaction.
We chose to design the MEMS device to generate a uniform temperature throughout the Nano-Cell. In other words, no temperature gradients are present that could lead to complications. This also allows to accurately measure and control the temperature of the liquid and the sample.

Temperature dependent etching kinetics of silica nanoparticles in-flask vs. in situ LPTEM, showing good similarity between both situations. Time = reaction time.

Silica nanoparticle experiment

To validate the effect of the combined flow channel and microheater, we looked at the etching process of silica nanoparticles in NaOH. This process is quite sensitive to temperature; increasing the temperature substantially accelerates the reaction kinetics. In-flask, the etching time in NaOH with pH 13.8 is reduced from ~500 to ~10 minutes when increasing the temperature from 20 to 60 °C. This was found by measuring the transmittance of the solution. The TEM allows us to observe this process in real time, at the nanoscale. In the Stream, we aimed to reproduce the reaction conditions from the in-flask experiment. In the flask, the bulk liquid acts as a large reservoir of available reactant species, while in the Nano-Cell, the space is much more confined. A constant flow was used to refresh the solution to make sure that the silica particles are etched by fresh reactants continuously.
We found very good similarity between the results obtained in-flask and in situ. In the Nano-Cell, the etching time reduced from 360 to 4 minutes for the same temperature increase from 20 to 60 °C. So in both cases, the same order of magnitude increase in etching rate is observed, indicating that the Nano-Cell meticulously mimics the situation outside the microscope. This was the most important finding from the paper. The e-beam seems to slightly accelerate the etching process, but the low dose imaging procedure ensured that the effect of the e-beam was reduced to a minimum.

“The most exciting part of the Stream holder is that the control it offers over temperature and flow means that we have access to a completely new phase space to observe dynamic processes, this will undoubtedly result in the discovery of new nanoscale phenomena and lead to innovations in materials synthesis.”
Dr. Joseph P. Patterson
Department of Chemistry and the department of Materials Science and Engineering,
University of California, Irvine, USA

Collaboration with customers

DENSsolutions actively participates in the scientific community. We work closely together with our customers to make sure that our products help them to generate impact. This study is a good example where our expertise in the design and engineering of the in situ system was combined with the expertise at TU Eindhoven and UC Irvine.

In Eindhoven they were already very experienced working with the silica nanoparticle samples and with the ex situ etching behavior at different temperatures. So when the MEMS devices for Stream Liquid Heating were launched, they proposed to run this experiment inside the microscope. We anticipated that one of the key parameters to control during the experiment would be the e-beam, as it could interfere with the etching process. Fortunately the groups at Eindhoven and Irvine have a thorough background in imaging soft matter, so we managed to adhere to a low dose imaging protocol to successfully minimize the beam effect.

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Wildfire In Situ heating system enables capturing the Structural evolution of co-catalysts

Wildfire In Situ heating system enables capturing the Structural evolution of co-catalysts

Original article by Siyuan Zhang, Leo Diehl, Sina Wrede, Bettina V. Lotsch and Christina Scheu. Published in Catalysts 2020, 10, 13.

There is a pressing need to develop renewable solutions for energy conversion and storage. Photocatalysis feeds both birds by one scone, utilizing a semiconductor to harvest solar energy, and co-catalysts to convert the energy into fuels. Such photocatalytic composites are often synthesized in nanometre-size to benefit from large surface areas. Seeing the structure of these “nano-composites” is a fundamental step for rational designs toward higher catalytic activity.

Controlled Heating

In this study, scientists from the Max Planck Institute (MPIE) designed a photocatalytic nanocomposite system with an ultimately thin semiconductor – a single crystal layer of 1 nm thickness. The co-catalysts are similarly tiny, synthesized with controlled heating by a DENSsolutions Wildfire system inside a transmission electron microscope (TEM). Structural evolution of the co-catalysts is captured by in situ TEM observations, based on which a design of co-catalysts with improved photocatalytic activity was demonstrated.

Figure 1. Growth of Ni nanoparticles from the nanocomposite with 10 wt% Ni loading during in situ heating under vacuum. Scale bars in both image sets (a), (b) are 50 nm. (figure from Siyuan Zhang, Max-Planck-Institut für Eisenforschung GmbH, published in https://doi.org/10.3390/catal10010013)

The NiOx co-catalyst was generated from the Ni(OH)2 precursor using a dehydration process. The reaction is irreversible, and the nucleation of the NiOx nanoparticles occurs in a split second.
“The low bulging of the Wildfire chips allows me to keep the atomic resolution imaging with ease and observe the onset of the fast nucleation kinetics.
The latter process of nanoparticle growth is much slower and requires substantial areas for statistics. The fast and reliable temperature ramp up and quench down of the Wildfire chips enables me to monitor the structural evolution over multitudes of areas from global views to atomic resolution imaging.
Moreover, I have run these heating experiments using two generations of Wildfire chips. The sample preparation has become much easier with the new generation, as the droplet of my nanocomposite suspension can be reproducibly dried on the heating area.”
Dr. Spark (Siyuan) Zhang
Max-Planck-Institut für Eisenforschung

The mystery of x

The research is motivated by the fundamental question in materials science, the relationship between structure and properties. The reaction rate is a number to be optimised in photocatalysis. On the other hand, the structure of the studied nanocomposite is multifarious. In addition to capturing the nucleation and growth of NiOx nanoparticles, we reveal the mystery of x in the chemical composition. By repeated heat treatment protocols, nanoparticles during various stages of growth can be “frozen” for microanalysis. By electron energy loss spectroscopy and multi-variate statistical analysis (https://doi.org/10.1093/jmicro/dfx091), a metallic Ni core and an oxidized shell of NiOx is resolved.

Challenging common wisdom

With the resolution power of a modern TEM plus the accurate and stable heating provided by DENSsolutions, we can study the ultimate miniaturized nanocomposite for photocatalysis. The common wisdom to maximize surface areas of catalysts is challenged by our findings, as we exemplify improved activity from core/shell co-catalysts with sufficient spacing between them.

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Learn all about our latest Impulse release

A conversation with our Product Architect (UX) Merijn Pen.

DENSsolutions introduces the new Impulse 1.0 software. This new Impulse allows you to take complete control of your in situ TEM experiments, performed with our Wildfire, Lightning and Climate systems. We interviewed our Product Architect (UX) Merijn Pen who led the development of this new release to get all the ins and outs. 

Why was this new version of Impulse developed?

As the DENSsolutions In Situ portfolio grows, so does the number of stimuli that our users can simultaneously introduce to their sample. Each additional stimulus brings its own set of parameters that need to be controlled and monitored, which used to make running In Situ experiments increasingly complicated.
To run an experiment with our Climate system for example, the user needs to control the sample temperature and several gas condition parameters with high accuracy while simultaneously performing measurements such as calorimetry and mass spectrometry. To be able to perform such an experiment, intuitive software is needed to reduce the complexity of operation while at the same time offering full control for every individual parameter.
In order to draw meaningful conclusions, our users want to understand the influence of an individual parameter change on the process that they study. Isolating the influence of a single parameter change is only possible if you are able to reproduce the exact same experiment multiple times, meeting all the stimuli setpoints over and over again. The active involvement of the user in the operation of the stimuli can cause problems as it introduces uncontrolled variables that can lead to variation between experiments. Impulse was developed to eliminate these issues by introducing experiment automation.

What are the main benefits of this new version?

Our previous release, Impulse 0.5, already made it possible for users to perform heating and biasing experiments from a single easy-to-use interface. With this update, we have added the Gas Supply Systems and Gas Analyzer so that Climate users also benefit from complete system integration in Impulse.

The Profile Builder environment, where users can design their experiments for automation, has been upgraded with Smart Automation. This new feature guarantees reproducible experimental conditions, even for complex systems with interdependent parameters such as the Gas Supply System. Now, a single operator can perform and reproduce experiments with ease and trust the results. The possibility to automate the complete range of stimuli from one experiment profile also enables users to optimize their experimental conditions on a bench setup which saves valuable time at the TEM.

Another important feature in Impulse is the flexible dashboard that can adapt to any type of experiment and offers a complete overview in a single glance. The user can add, remove, rearrange and resize graphs to create the perfect overview. With this dashboard, users are able to quickly detect changes and draw conclusions from the data.

And lastly, the Impulse 1.0 software produces synchronized data that can easily be imported into Gatan Microscopy Suite and TVIPS software. This enables the user to quickly correlate their in situ data with the TEM images and makes it easier to create images that can be used in publications.

Who are the people that will benefit from it?

Impulse is compatible with all Wildfire, Lightning and Climate systems, so all existing users can benefit from this new release. As well as any new customer, as Impulse will be shipped with any new system sold after the 1st of June.
Some of our Wildfire and Lightning customers are already familiar with the previous release, Impulse 0.5. For those customers, the free upgrade to Impulse 1.0 brings numerous incremental improvements that were developed based on the feedback that some early users have shared with us.
Climate users will notice significant benefits from this new release. These users can now control and automate complete heating, gas and gas analyzer experiments with Impulse. Plus, there are some new features that are tailored for gas and heating experiments, such as Real-time Calorimetry and Smart Automation.

What kind of challenges were tackled during development?

One of the biggest challenges during development was improving the ease-of-use without sacrificing functionality. On the one hand, we strive to make the experiment workflow as simple as possible, on the other hand we want to offer maximum flexibility for controlling the sample conditions.
With Impulse 1.0 we have managed to combine the complete range of controls and parameters into one easy to use interface, without compromising on functionality and flexibility.

Did we cooperate with customers on this development?

Of course! Customers are at the heart of our designs so we have involved customers throughout the conceptualization, development and testing phases of Impulse. This gave us a lot of insight and, in the end, resulted in a better product.

We will continue to listen to our customers while we expand the capabilities of the Impulse platform in future developments. For this reason we have set up an online service desk at support.denssolutions.com where I invite all customers to share their feature ideas and feedback to help define the future of In Situ TEM.

What is the compatibility of Impulse 1.0?

Impulse 1.0 software is compatible with the DENSsolutions Wildfire, Lightning and Climate systems. Impulse connects to the DENSsolutions Heating Control Unit (HCU), Keithley 2450 source measuring unit (SMU), the DENSsolutions Gas Supply Systems and DENSsolutions Gas Analyzer.

Which future developments lie ahead?

The next big step will be to turn Impulse into an open platform. We will develop an open API to enable collaborations with other brands, integrations into more software platforms and advanced experiment controls through scripting.

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