Installing South Korea’s second Stream system at Seoul National University

Installing South Korea’s second Stream system at Seoul National University

DENSsolutions Installing South Korea's second Stream system at Seoul National University

The team at SNU (From left to right) Prof Jungwon Park, Back Kyu Choi, Minyoung Lee and Junyoung Heo.

With the second ever installation of a Stream LPEM Solution in South Korea, we get an insider’s look at the microscopy laboratory at the Seoul National University. We interviewed Prof Jungwon Park from the National Center for Inter-University Research Facilities to find out how our solutions will benefit their research when investigating synthetic mechanisms of inorganic nanocrystals.

Can you tell us a bit about the microscopy facility at Seoul National University SNU?

Seoul National University has a shared research facility called NCIRF (National Center for Inter-University Research Facilities) that has specialities in various fields of analysis, such as organic, inorganic, surface analysis, and x-ray techniques. NCIRF also has a special team in electron microscopy, which provides SEM, TEM, and other pretreatment equipment including FIB and Nanomill.

This shared facility was established around 30 years ago. Recently, two spherical aberration-corrected TEM and STEM, JEM-ARM200F, were installed, providing atomic-resolution electron microscopy images. Also, in our own center, the Institute for Basic Science Center for Nanoparticle Research, we have our own JEOL JEM-2100F TEM in our building which is utilized routinely for a lot of in situ EM studies.

What type of applications are your users interested in with regards to the Stream system installed?

Our users are interested in various nanocrystal dynamics. Regarding the Stream system, we are expecting to investigate the synthetic mechanism of colloidal inorganic nanocrystals by changing the liquid cell temperature and injected precursor solution. Also, we are planning to investigate transformation phenomena of colloidal nanocrystals in various liquid environments. Moreover, we are expecting to observe polymers or proteins in liquid, and their stimuli-responsive reactions using the Stream system.

What particular features of the DENSsolutions Stream solution attracted you to the system?

When it comes to liquid cell TEM experiments, it is crucial to ensure that a controlled amount of liquid is injected to the desired position, while minimizing the decrease in spatial resolution of TEM stemming from the window bulging effect. In this sense, the Stream system by DENSsolutions was quite attractive to us.
With ensured liquid flow from Nano-cell design, controlled injection of liquid, as well as mitigated window- bulging originating from the pressure-based liquid pump, and also along with the liquid heating control system, the Stream solution seemed to help us to design various in situ liquid cell systems which were unachievable with other in situ holders.

What particular features of Stream attracted you to the system?

For our experiments, it was essential to find a way to control the flux of the liquid within the liquid cell in order to look at reactions or processes occurring on the location of the electron beam. This is something we were unable to do with previous generations of holders and chips. The DENSsolutions Stream system is the only system that allows you to completely control the liquid flux. This unique capability is what intrigued us most about the system.
Moreover, as a result of the Nano-cell’s special inlet-outlet design, we are also able to fully control the pressure and liquid thickness. Other features that we found very attractive include the control systems like the heating control unit and the pressure-based pump, which are considerably more elaborate compared to what we had in the past.

In your experience so far, how have you found the Stream system?

At first, the Stream system was quite complicated to us since a lot of elaborate systems were installed. But soon we realized that it was much simpler than it seemed. The method to assemble the Stream holder was easy compared to other liquid cell TEM holders, and the way to control the injection solution was straightforward. And since a lot of O rings are used to encapsulate the Nano-cell, the holder seems to be very stable without leakage problems while operating the TEM. Also, the heating control software was upgraded from the Wildfire version, making it much easier to use the program.

DENSsolutions Prof. Jungwon Park

Jungwon Park, Ph.D
Associate Professor | Seoul National University

Jungwon Park received his B.S. degree from the Department of Chemistry, POSTECH, South Korea, in 2003, and his Ph.D. degree from the Department of Chemistry, University of California, Berkeley, in 2012. After a post-doc with the School of Engineering and Applied Sciences, Harvard University, he started a faculty position with the School of Chemical and Biological Engineering, Seoul National University, in 2016, and he currently serves as an associate professor jointly affiliated with the Center for Nanoparticle Research, Institute for Basic Science (IBS). His research areas include the in-situ study of nanomaterials, liquid-phase TEM, phase transitions, interface chemistry, and low-dimensional materials.

Learn more about Stream:

Discover Jungwon Park’s publications:

Discover publications made possible by Stream:

Do you want to receive great articles like this in your mailbox? Subscribe to our newsletter.

Installing the first Stream system in Singapore at the Nanyang Technological University

Installing the first Stream system in Singapore at the Nanyang Technological University

Standing next to the recently installed Stream system: from left, Dr. Anastasia Shebanova, Dr. Martial Duchamp and Jeffrey George from the Nanyang Technological University

We are happy to announce that the first ever Stream system in Singapore has recently been installed! For this event we interviewed Dr. Martial Duchamp from the School of Materials Science and Engineering at the Nanyang Technological University (NTU) in Singapore. In this interview, we discussed NTU’s advanced microscopy facility and the various applications that LPEM users are interested in, as well as how our Stream system has greatly benefited their research.  

Can you tell me a bit about the microscopy facility at the Nanyang Technological University?

The Nanyang Technological University has a shared microscopy facility called FACTS (Facility for Analysis Characterization Testing & Simulation) that specializes in characterization in the field of electron microscopy and x-ray techniques. FACTS provides state-of-the-art electron microscopes and X-ray instruments as well as the expertise to operate them to all of NTU and beyond.

This shared facility was created around 20 years ago. Four years ago, we had an extension of the facility, and got two aberration-corrected transmission electron microscopes as well as a new building where these TEMs were installed. The first TEM is a JEOL JEM-ARM200F, and the second is the JEOL JEM-GrandARM that is both probe- and image-corrected. Moreover, we have some local technicians and engineers who take care of these microscopes and make sure the facility is running well.

What type of applications are Stream users at the facility interested in?

Users of the facility are interested in a wide range of applications. In regards to LPEM users, we are using the DENSsolutions Stream system to study the liquid-liquid phase separation (LLPS) aspect of biological systems. Specifically, we are interested in the process called coacervation, which involves starting with a mixed phase of polymer or proteins dispersed in a solvent, and by changing certain conditions like the pH, temperature or salt concentration you can go from this diluted phase to a solid phase via phase separation. We are particularly interested in phase separation in order to understand how we go from these diluted solutions of drugs or proteins to solid matter.

Aside from liquid TEM, I am also interested in using in situ and operando TEM to observe 2D materials and the evolution of these materials versus temperature, as well as solar cells and batteries.

Can you tell us who won the grant to acquire the Stream system?

Associate Professor Ali Miserez, the lead PI of the project titled “Phase Separation-Regulated Life, In and Outside of Cells”, was awarded the Ministry of Education (MOE) Tier 3 grant worth 8.5 million Singaporean dollars. This research programme aims to closely integrate the tools of cell biology and colloidal biochemistry with the framework developed in the materials science of polymer science, soft matter, and complex fluids. The goal is to unravel LLPS-mediated functional organization across multiple biological length scales. Part of this grant was used to acquire the Stream system.

This 5-year project started last summer, and we are just starting to employ new researchers. In fact, some students already started a couple months ago and we expect to have some more people joining.

What particular features of Stream attracted you to the system?

For our experiments, it was essential to find a way to control the flux of the liquid within the liquid cell in order to look at reactions or processes occurring on the location of the electron beam. This is something we were unable to do with previous generations of holders and chips. The DENSsolutions Stream system is the only system that allows you to completely control the liquid flux. This unique capability is what intrigued us most about the system.

Moreover, as a result of the Nano-cell’s special inlet-outlet design, we are also able to fully control the pressure and liquid thickness. Other features that we found very attractive include the control systems like the heating control unit and the pressure-based pump, which are considerably more elaborate compared to what we had in the past.

In your experience so far, how have you found the Stream system?

The assembly in regards to the closing of the cell is quite straightforward, and so far we have not had any leakage issues. Just by closing the cell, it becomes airtight, which is a great advantage of the system. Moreover, what I really appreciate about the system is the ability to have complete control over the flow of the liquid.

Dr. Mihaela Albu

Dr. Martial Duchamp
Assistant Professor | Nanyang Technological University

Dr. Martial Duchamp is an Assistant Professor in the school of Materials Science and Engineering at the Nanyang Technological University in Singapore. His research interests include the development of innovative operando TEM methods for application to solar cells, batteries and fuel cells devices, as well as obtaining a fundamental understanding of 2D materials to reveal their unprecedented electrical properties at local scale.

Learn more about Stream:

Discover Martial Duchamp’s publications:

 

Discover publications made possible by Stream:

Do you want to receive great articles like this in your mailbox? Subscribe to our newsletter.

Achieving mass transport control with the award-winning Stream system

Achieving mass transport control with the award-winning Stream system

The on-chip flow channel of the Stream system allows for full control over pressure, flow rate, liquid thickness and electric potential

Original article by Anne France Beker, Hongyu Sun, Mathilde Lemang, Tijn van Omme, Ronald G. Spruit, Marien Bremmer, Shibabrata Basak and  H. Hugo Pérez Garza

The liquid phase transmission electron microscopy (LPTEM) community faces numerous challenges when performing in situ electrochemical studies inside the TEM. From a lack of control over the flow and liquid thickness, to limited experimental flexibility and reproducibility, these challenges have posed considerable limitations on research. As a result, DENSsolutions has developed an in situ LPTEM solution that addresses each and every one of these challenges – the Stream system. Due to its unique on-chip flow channel design, users can effectively control experimental conditions such as pressure, flow rate, liquid thickness, electrical potential and bubbles. STEM videos are shown below to demonstrate these advantages and visualize the in situ growth of copper with multiple morphologies.

Because you can independently control the pressure at the inlet and outlet of the Stream Nano-Cell, you can control the absolute pressure in the microfluidic channel. This state-of-the-art design consequently gives you full control over the flow and the bulging of the windows, and therefore the liquid thickness. As a result, spatial resolution is improved, enabling meaningful electron diffraction and elemental mapping in liquid. You can accurately define the mass transport and control the electric potential, granting you complete access to the full kinetics of the reaction.

The in situ LPEM study

In order to exhibit the benefits of the system, copper dendrites were grown and characterized in situ. After the electrodeposition of the copper, EELS and EDS characterization were performed with copper inside the viewing area. Furthermore, high resolution images and diffraction patterns of the grown copper dendrites were recorded using the TEM.

Removal of beam-induced species

A major issue when performing LPTEM experiments with an electrolyte is the undesired influence of the electron beam. In this experiment, the electron beam interacts with the copper electrolyte. However, because you can control the flow of the liquid, you can remove or flush away any unwanted beam-induced species from the region of interest (i.e. window, sample or electrodes). This is displayed in the STEM recording below with the flow moving from right to left.

STEM movie showing debris being flushed

Bubble dissolution

It is important in LPTEM to assure that the cell stays wet. However, when bubbles form, the cell starts to dry out. The Stream system was developed with this in mind, offering a solution to this challenge. Specifically, because you can control the absolute pressure in the microfluidic channel, you can remove unwanted gas bubbles by setting the pressure high. At higher pressures, the size of the bubble decreases until it disappears and vice versa. The dissolution of a bubble that was formed during this copper experiment is shown in the STEM video below.

STEM movie showing bubble dissolution

In situ growth of copper dendrites

The growth and stripping of copper was completed a few times via cyclic voltammetry. The cycles begin with copper reduction, corresponding to the growth of the copper dendrites. Next, oxidation takes place, corresponding to the copper dendrites being stripped. Interestingly, you can see in the STEM video below that after reduction, the dendrites are thicker whereas after oxidation, the dendrites become much thinner.

STEM movie showing 5 cycles of copper growth and etching

Liquid thickness control 

In order to perform high resolution imaging, it is important in LPTEM that the liquid thickness is kept low. Aside from high resolution imaging, controlling the liquid thickness is extremely important when performing analytical techniques like EDS, EELS and electron diffraction. Ideally, the liquid should be limited below the beam broadening, which is normally expected to happen around 500nm of liquid thickness. With this in mind, we designed our Nano-Cell such that the thickness stays below the beam broadening threshold based on the spacer thickness and the maximum bulging of the windows. In the figures below, the elemental mapping and electron diffraction of the electrodeposited copper are presented. 

Elemental mapping - Anne article

EDX elemental mapping showing the spatial distribution of b) the copper dendrites and c) the platinum electrode 

Electron diffraction Annette article

TEM image of the copper dendrites on the electrode in e) and the corresponding SAED patterns in liquid phase in f)

Complete flow control

Controlling the flow also has other important advantages that are expanding possibilities in research. Namely, the ability to manipulate the flow rate allows you to control the morphology. You can see in the STEM image below that when flow is applied, the copper grows in a continuous layer with more copper being deposited. On the other hand, without flow, the copper nuclei grow isolated. This is direct proof that the unique flow-control feature of the system allows you to control the kinetics of an electrochemical reaction.

Morphology of copper with and without flow using the Stream system

Conclusively, this research highlights the unique capabilities of the award-winning Stream system, proving its potential to enable and boost research in various application fields, ranging from battery research and fuel-cells to corrosion and electrocatalysis.

Original article:

More about Stream:

Do you want to receive great articles like this in your mailbox? Subscribe to our newsletter.

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.

Download the brochure:

Read an article:

See a customer publication:

Request a demo:

Do you want to receive great articles like this in your mailbox? Subscribe to our newsletter.

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.

Original article:

More about Stream:

Do you want to receive great articles like this in your mailbox? Subscribe to our newsletter.

Driving the field of LPEM forward at the Gordon conference

Driving the field of LPEM forward at the Gordon conference

Last month, our Stream Product Manager Gin Pivak, CTO Hugo Perez and Microsystems Engineer Tijn van Omme visited the Gordon Research Conference (GRC) on Liquid Phase Electron Microscopy (LPEM). They were there to inform the LPEM community about our Stream system which allows researchers to introduce an accurate and controlled liquid environment combined with in-situ heating or biasing possibilities.
We realized that most researchers were still assuming that all liquid holders for LPEM are still relying on the ‘bathtub’ style (i.e. pocket structure where the 2 chips are placed). This is far from ideal, as the liquid bypasses the nano-cell and it only flows towards the window by diffusion in a non-controlled and spontaneous way. Therefore, it was a big relief for the LPEM community to learn that our Stream system now enables the real benefits, like (a) accurately controlling pressure and flow over the window, (b) controlling membrane bulging (i.e. controlling the liquid thickness) to enable higher resolutions, (c) enabling meaningful results in structure determination and analytical microscopy studies (e.g. EDS, EELS, electron diffraction), (d) controlling and mitigating bubble formation and most importantly, (e) reproducible experiments.
The Gordon Research Conferences are a special type of conference aimed at advancing frontier research. The idea is to bring all the relevant people in the field together to discuss and present (unpublished) results and to talk about the future directions of the field. All the major players in the field were present, and there was a lot of time for interaction. This created an open atmosphere, in which knowledge was shared and collaborations were established.
It became clear that the Liquid Phase Electron Microscopy community is maturing. LPEM offers a unique way for scientists to obtain information within a wide range of fields, including nanoparticle synthesis, self-assembly, corrosion, batteries, semicon, proteins and cells. However, compared to Cryo-EM, the field is still in its early days. A number of challenges still exist before results will be reproducibly accepted by non-microscopist communities. For example how to deal with the influence of the e-beam and how to control other influencing parameters.

‘Bathtub’ style LPEM system. Liquid bypasses the Nano-Cell and flows toward the window in a non-controlled and spontaneous way.

DENSsolutions Stream LPEM system. On-chip microfluidic channel enables full control over the liquid flow and pressure, thus the liquid-sample interaction.

On the first day of the conference, our CTO gave a presentation about the Stream Liquid Biasing and Liquid Heating system which resonated well amongst the attendees. The on-chip microfluidic channel in combination with the pressure control in the Stream system aligns well with the current and future demands of the field, as it enables control over the flow and liquid layer thickness.

Thank you for reading

To learn more about our LPEM system:

Do you want to receive great articles like this in your mailbox? Subscribe to our newsletter.