Radboudumc expands its bio-research capabilities with newly installed DENSsolutions Stream system

Radboudumc expands its bio-research capabilities with newly installed DENSsolutions Stream system

We are excited to announce that DENSsolutions has installed a Stream system at the renowned Radboud University Medical Center (Radboudumc) in Nijmegen, the Netherlands. In this article, we interview Luco Rutten, PhD Candidate at Radboudumc, to learn more about the institute’s electron microscopy center, the team’s research direction and the pivotal role our Stream system will play in advancing their bio-research initiatives.

What is the Radboudumc Electron Microscopy Center known for?

“The Radboudumc Electron Microscopy (EM) Center, established in 2019 under the leadership of Dr. Anat Akiva and Prof. Dr. Nico Sommerdijk, operates as part of the RTC Microscopy within Radboud University Medical Center in Nijmegen, The Netherlands. Specializing in cutting-edge imaging and analysis techniques, including cryo-correlative light electron microscopy (cryo-CLEM), the EM Center serves users from both academia and industry. Notably, the center is equipped with a recently installed 200 kV Thermo Fisher Scientific TALOS F200C-G2 transmission electron microscope, featuring a Falcon 4i Direct Electron Detector, segmented STEM detector and EDS detector.”

What type of applications are the EM Center’s users interested in using Stream for?

“Since the Electron Microscopy Center is part of the University Medical Center, we are especially interested in using Stream to study biological and biomimetic processes under relevant conditions. For instance, the aggregation of protein-calcium complex and the biomineralization of organic scaffolds such as collagen mimicking health and disease. By adding the dynamic information from liquid phase EM to our cryo-CLEM workflow, we can unravel the mechanisms at the nanoscale of life.”

What particular features of Stream stood out to you?

“With our aim to study biological processes, the ability of the Stream system to seamlessly approach physiological conditions is of great importance. Since life occurs at 37 °C, precise control over the temperature is critical. Moreover, with Stream we are able to control liquid flow, enabling us to work with concentrations very close to physiological conditions. Additionally, we often deal with hybrid systems composed of both organic and inorganic materials, which can limit the contrast. By controlling the bulging of the windows through adjusting the front and back pressure, we’re able to reduce the liquid thickness as much as possible.

Could you tell us a bit more about the funding granted to acquire the systems?

“Prof. Dr. Nico Sommerdijk, the lead PI of the project titled ‘In Situ Imaging of Biological Materials with Nanoscale Resolution using Liquid Phase Electron Microscopy’, was awarded the NWO-groot grant of 1.5 million euros by the Dutch Scientific Organization to acquire state-of-the-art equipment for liquid phase electron microscopy to study biological processes. Part of this grant was used to acquire the Stream system. The aim of the program is to establish a globally unique facility dedicated to liquid phase electron microscopy on biological materials. The integration of the latest developments in software, hardware and sample preparation techniques will broaden the range of biological materials that can be investigated.”

In your experience so far, how have you found working with Stream?

“Operating the Stream system becomes quite routine after working with it a couple of times. The recent workshop organized by DENSsolutions for Stream users (see image below) provided a valuable opportunity to learn from experts like Dr. Hongyu Sun, DENSsolutions Senior App Scientist, and exchange experiences in working with the holder with other participants.

From left to right: Dr. Hongyu Sun (DENSsolutions), Luco Rutten (Radboudumc), Yannick Rutsch (FZ Jülich) and Rebecka Rilemark (Chalmers University of Technology)

Luco Rutten
PhD Candidate |  Electron Microscopy Center, Radboudumc

Luco Rutten received his Master’s degree in Chemistry and Chemical Engineering from the Eindhoven University of Technology. He is in his last year of his PhD at \Radboudumc under the supervision of Dr. Elena Macías-Sánchez and Prof. Dr. Nico Sommerdijk. As part of the Biomineralized Tissues group and the Electron Microscopy Center, he is using advanced electron microscopy to study bone mineralization mechanisms.

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Introducing Lightning Arctic: Our latest In Situ TEM Cooling, Biasing & Heating solution

Introducing Lightning Arctic: Our latest In Situ TEM Cooling, Biasing & Heating solution

An interview with DENSsolutions Senior Product Manager Dr. Gin Pivak about our latest addition to the Lightning product family: Lightning Arctic.

DENSsolutions introduces its latest product: Lightning Arctic – an innovative in situ solution that can perform cooling, biasing and heating all in one system. In this article, we interview our Senior Product Manager Dr. Gin Pivak to learn all about Lightning Arctic, including its unique capabilities and wide application space.

1) What are the main application fields that will benefit from Lightning Arctic?

“There are numerous applications where Lightning Arctic can play an important role. The ability to cool a sample and apply electrical stimuli enables researchers to study low-temperature physics, reaching temperatures as low as 100 Kelvin. It can be utilized to investigate magnetic materials and nanostructures, superconductors, topological insulators, ferroelectrics and more. Additionally, the application of Lightning Arctic can be expanded to include beam-sensitive materials such as Li-ion batteries, organic superconductors and perovskite-based solar cells, where the cooling capability can prolong the material’s lifespan under the electron beam. Furthermore, the ability to perform electro and/or thermal experiments at high temperatures allows the Lightning Arctic system to be used in the fields of nanomaterials sintering and growth, metals and alloys, low-dimensional materials, resistive switching, phase-change materials, solid oxide fuel cells, piezoelectrics, solid-state batteries and so on.”

2) Has the system already been installed?

“Yes, the system has been installed at the Faculty of Engineering, Department of Materials at Imperial College London (ICL) in the UK. The main user of the Lightning Arctic system at ICL is Dr. Shelly Conroy, who is exploiting various ferroelectric and quantum materials at low temperatures and at atomic resolution.”

3) What are the main benefits of Lightning Arctic for users?

“Lightning Arctic brings forth numerous advantages for your in situ experiments:

1) Perform in situ cooling and heating experiments: A cooling rod inside the Lightning Arctic holder can transfer the ‘cold’ towards the tip of the holder where the MEMS-based Nano-Chip holding the sample is located. Once this cooling rod is connected to a detachable metallic cooling braid which is immersed in an external dewar filled with liquid nitrogen, the sample can be cooled inside the TEM down to liquid nitrogen temperatures. Aside from cooling, the Lightning Arctic holder also enables in situ heating experiments, where the temperature can reach 800 °C and even 1300 °C depending on the chip used.

2) Experience atomic imaging stability: The Lightning Arctic holder was uniquely designed to host a number of additional temperature controllers that work to stabilize the sample drift during cooling. One controller ensures the temperature equilibrium with the TEM while the other stabilizes the cold influx towards the sample. The usage of the external dewar that helps to minimize the liquid nitrogen bubbling ensures that atomic imaging with low sample drift can be achieved.

3) Continuous temperature control: Our state-of-the-art Heating and Biasing Nano-Chips enable the local manipulation of the temperature of the sample while not disturbing the cooling process of the holder. This means that you can achieve the fast setting of any user-defined temperature and the minimization of the image and focus shift when changing the temperature setpoint, all while ensuring atomic-scale imaging quality.

4) Achieve your required sample orientation: The double tilt Lightning Arctic holder allows tilting the sample in both alpha and beta directions of 10 – 25 degrees to find the required zone axis of the sample.

5) Perform in situ biasing experiments while cooling/heating: The Heating and Biasing Nano-Chips compatible with the Lightning Arctic holder contain biasing electrodes that can be used to apply and measure electrical signals either during cooling or during heating. Of course, the preparation of FIB lamellas on the Nano-Chips for electrical experiments is very crucial. There are already proven methods and tools developed for the Lightning system (like the DENSsolutions FIB stub) that can be used to prepare top-quality, short-circuit-free FIB lamellas on the Heating and Biasing chips for the Lightning Arctic system.

6) Wide compatibility of the sample carriers: Lightning Arctic has a similar Nano-Chip compatibility to the Lighting system, and works with Wildfire heating Nano-Chips and Lightning heating and biasing Nano-Chips. Moreover, the Lightning Arctic holder is also compatible with 3mm and lift-out TEM grids that can be used to study beam-sensitive materials at cryo-conditions without the need of using the Nano-Chips. This greatly expands the range of samples that the new in situ solution can work with.”


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DENSsolutions successfully installs both a Stream and Climate system at Cardiff University

DENSsolutions successfully installs both a Stream and Climate system at Cardiff University

From left to right: Oliver Mchugh and Dr. Thomas Slater from Cardiff University, Dr. Lars van der Wal and Alex Rozene from DENSsolutions

We are excited to announce that DENSsolutions has installed both a Stream and Climate system at the renowned Cardiff University in Wales, the United Kingdom. In this article, we interview Dr. Thomas Slater, Lecturer at Cardiff University, to learn more about the Cardiff Catalysis Institute Electron Microscope Facility, the team’s research direction and the pivotal role our Stream and Climate systems will play in advancing their research initiatives.

Can you tell me about the Cardiff Catalysis Institute Electron Microscope Facility?

“The Cardiff Catalysis Institute Electron Microscope Facility (CCI-EMF) is based at Cardiff University, one of Britain’s leading research Universities. The CCI-EMF is a new, world-class electron microscopy facility located in the University’s Translational Research Hub on its Innovation Campus. It houses an array of state-of-the-art imaging and analytical instruments designed around the study of heterogeneous catalysts and nano materials. The mission of the facility is to provide researchers in academia and industry with cutting-edge microscopy equipment, creating a Welsh hub for electron microscopy expertise and skills development.

In October 2022, we installed a 200 kV Thermo Fisher Scientific Cold-FEG Spectra 200. This aberration-corrected scanning transmission electron microscope (AC-STEM) is the first of its type in Wales. It is optimised for the study and analysis of heterogeneous catalysts and nanoparticles and is fitted with the Super-X EDS detector, Panther STEM detection system for HAADF/BF and iDPC imaging, Gatan’s Continuum ER EELS and Quantum Detectors Merlin detector. The facility also hosts a JEM-2100 LaB transmission electron microscope with a high-resolution Gatan digital camera and Oxford X-max EDS detector and a Tescan MAIA-3 field emission gun scanning electron microscope (FEG-SEM), which enables secondary electron (SE), in-beam SE, low-kV backscattered electron (BSE), in-beam BSE and scanning transmission electron microscopy (STEM) imaging capabilities.”

What type of applications are the users at CCI-EMF interested in using the Stream and Climate systems for?

“The Stream In Situ TEM Liquid + Biasing or Heating system will enable us to study liquid-phase reactions and follow the mechanisms of nanoparticle synthesis in solution. Nanoparticle growth and crystallization on the surface of metal oxide supports is of particular interest to us, along with catalyst stability in solution and the mechanisms of deactivation through leaching and particle migration.

The Climate In Situ TEM Gas + Heating system will allow the CCI researchers to conduct operando STEM, TEM and chemical imaging of heterogeneous catalysts under reaction conditions. We aim to develop an improved understanding of structure-activity relationships, oxidation and reduction processes, catalysts synthesis, catalyst stability and deactivation mechanisms. Crucially, we will be able to study changes in the structure and chemistry as a function of temperature, pressure and composition, improving our understanding of catalysed processes at or near real reaction conditions.”

What particular features of the DENSsolutions systems stood out to you?

“For us it was critical to have excellent thermal stability, a uniform heated zone and fast gas mixing at the cell to ensure reproducibility and correlation with our larger scale benchtop micro- reactors. Chemical compatibility with a wide range of reaction gases and catalyst materials was also important as we support a vast number of researchers across multiple research projects with very different experimental requirements.”

Could you tell us a bit more about the funding granted to acquire the systems?

“The system was purchased with European Regional Development Funding (ERDF) through the Welsh European Funding office (WEFO) and part-funded by The Wolfson Foundation. The funding enabled the CCI to establish its own EM facility through the purchase of advanced microscopes and equipment such as the DENSsolutions Stream and Climate systems. This capability enhances and strengthens the already outstanding catalyst research facilities of the CCI and our aim is to use this new capability to support the research needs of the University, our existing partners, local industry as well as develop new research strands.”

In your experience so far, how have you found working with Stream and Climate?

“The installation went very smoothly and was completed in a couple of weeks, including the 3 days of training. The hardware is robust, and the chip assembly relatively intuitive. We are able to have chips prepared, assembled, leak-checked and in the microscope within the space of a couple of hours which leaves the rest of the days free for experiments. The parameter control is made easy through the Impulse software workflow which guides you from start to finish. In fact, we were running experiments ourselves and generating data within a week of installation.”

Dr. Tom Slater
Lecturer |  Electron Microscopy of Catalytic Materials, Cardiff University

Dr. Tom Slater received his Ph.D. in Nanoscience from the University of Manchester, where he also did postdoctoral work in the Henry Moseley X-ray Imaging Facility. He then joined the electron Physical Sciences Imaging Centre (ePSIC) as an electron microscopy scientist. He was appointed as a Lecturer in Electron Microscopy of Catalytic Materials at Cardiff University in 2022, where his research focuses on imaging of heterogeneous catalysts.

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DENSsolutions’ Lightning system helps uncover the interaction mechanism in reactive metal-ceramic system, Al-SiC

DENSsolutions’ Lightning system helps uncover the interaction mechanism in reactive metal-ceramic system, Al-SiC

Using the DENSsolutions Lightning system, researchers were able to provide an electrical, chemical and structural analysis of the Al–amorphous SiO₂–SiC interface at high temperatures.

Original article by Adabifiroozjaei et al.

The use of hybrid materials containing both metals and ceramics has become increasingly popular within manufacturing and microelectronic industries due to their optimized and well-balanced properties. Aluminum-silicon carbide (Al-SiC) is a widely known metal-ceramic composite material, commonly used in microelectronic packaging for automotive and aerospace applications. In Al-SiC an amorphous oxide layer (AOL) of SiO₂ is known to exist between the Al and SiC. Notably, the mechanism of interaction between the reactive metal (Al) and ceramic (SiC) and the AOL (SiO₂) under the heat-treatment process is still not well-understood. In fact, numerous theories about the interaction mechanism have been proposed over the past few decades. The major problem is that the studies conducted so far, regardless of the mechanism proposed in them, were ex situ and therefore not capable of resolving the atomic-scale nanostructural and chemical changes occurring at the interfaces during the heat-treatment process. In a recent paper published in the Journal of Materials Science, involving our valued users at TU Darmstadt, Dr. Esmaeil Adabifiroozjaei and Dr. Leopoldo Molina-Luna, the DENSsolutions Lightning system was utilized to reveal the evolution mechanism of the Al–AOL–SiC system under heating and biasing conditions. This study involved a team of researchers from institutes all over the world, including the University of Tabriz in Iran, NIMS and Shibaura Institute of Technology in Japan, and UNSW Sydney in Australia. 

Sample preparation

The first step for Dr. Adabifiroozjaei and his fellow collaborators was to carefully prepare the Al-SiC sample. After ultrasonically cleaning the SiC wafer, removing the oxide layer and allowing its regrowth by inserting the wafer into a desiccator, an Al layer with a thickness of ~1 µm was sputtered on the wafer using Shibaura’s CFS-4EP-LL sputtering machine. Next, in order to prepare the lamella, the researchers applied focused ion beam milling using JEOL’s JIB-4000 FIB. The prepared lamella was then loaded onto the DENSsolutions Lightning Nano-Chip (see Figure 1a). The low- and high-magnification scanning electron microscopy (SEM) images of the chip and the loaded lamella are shown below in Figure 1b) and 1c), respectively. Next, an Au lamella was prepared by FIB and connected to Al–AOL–SiC lamella and chip in order to ensure electrical current passes through Al–AOL–SiC lamella.

Figure 1: a) DENSsolutions Lightning Nano-Chip used for the in situ heating and biasing experiment, b) low- c) and high-magnification SEM images of the loaded lamella on the Nano-Chip, respectively.

Experimental results

The researchers performed EDX and EELS elemental mapping to determine the chemical composition of the phases across the Al–AOL–SiC interface. The EDS mapping of the interface is shown in Figure 2a), while the high-resolution EELS elemental mapping of the interface is shown in Figure 3b) – both of which reveal the consistent presence of a narrow oxide layer with a thickness in the range of 3–5 nm. 

Figure 2: a) EDS elemental mapping of Al–AOL–SiC interface, showing the presence of the AOL, b) STEM-HAADF image of Al–AOL–SiC interface and its EELS map profile.

Next, the researchers began with the in situ heating and biasing experiment to study the electrical characteristics of the lamella. First, a compliance current was set to 3 nA, then the voltage required to reach such a current was recorded at each temperature. The acquired I–V curves for room temperature, 500 ° and 600 °C after 30 minutes of application of the field are presented in Figure 3a–c), respectively. The I–V curves and high resolution TEM images (shown in Figure 3d–f) indicate that the resistivity of the Al–AOL–SiC device decreased three orders of magnitudes at 500 °C with no apparent change in the nanostructure. 

Figure 3: a), b), and c) show the I–V curves of Al–AOL–SiC interface measured at room temperature, 500° and 600 °C, respectively. d), e), and f) show the high-magnification images of Al–AOL–SiC interface from a small area of low-magnification images.

The chemical changes occurring at the interface during the heating process were investigated on another lamella using the same DENSsolutions Lightning holder, but on a Wildfire (heating-only) Nano-Chip. HAADF-STEM images and EELS chemical profiles were acquired and the results are shown in Figure 4 below. 

Figure 4: a), b), c ) and d) show changes in chemistry (line profiles of Al (Aqua), Si (Violet), C (Lime), and O (Yellow)) of Al–AOL–SiC interface at room temperature (25°), 550°, 500° and 600 °C, respectively.

During this analysis, the researchers observed that at 550 °C, the AOL width was reduced, which was specifically due to AOL dissolution into the Al. Moreover, the analysis of the structural changes at the interface nanostructure at 600 °C showed that the dissolution of the SiO₂ amorphous layer resulted in the formation of α-AlO and Si within the Al. In contrast, the elemental interdiffusion (Al³⁺ ⇄ Si⁴⁺) between Al and SiC was observed to occur, resulting in formation of AlC. From the results, we can infer that the reaction mechanism between Al and crystalline SiC is different with that between Al and SiO₂ amorphous phase.


Dr. Adabifiroozjaei and his fellow collaborators performed a comprehensive in situ STEM heating and biasing study using the DENSsolutions Lightning system, investigating the electrical, chemical and microstructural features of the interface of a Al–AOL–SiC system. Performing this study under an ultrahigh resolution of 4 Å allowed the researchers to confirm, for the first time in literature, that the reaction mechanism between reactive Al and crystalline SiC is different than between Al and amorphous SiO₂. Specifically, they found that whereas the reaction between SiO₂ and Al follows the dissolution mechanism, the reaction between SiC and Al proceeds through elemental interdiffusion. Importantly, these findings might be applicable to other reactive metal-ceramic systems that are currently used in manufacturing and electronic industries.

“With the stability and accuracy provided by DENSsolutions Lightning system, we could reveal features of an interfacial interaction in a common metal-ceramic system (Al-SiC) that were not previously observed. Such studies at very high resolution are absolutely necessary for the understanding and future development of composite materials at elevated temperatures.” 

Prof. Dr. Leopoldo Molina-Luna   Professor  |  TU Darmstadt

Original article:


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Liquid flow control: Unlock untapped research capabilities within in situ LPEM

Using the DENSsolutions Stream system, researchers were able to create a highly controlled chemical environment for visualizing the nanoscale metallic electrodeposition of copper crystals.

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DENSsolutions successfully installs another Climate system in Japan, at JFCC

DENSsolutions successfully installs another Climate system in Japan, at JFCC

Top row – from left to right: Mr. Suzuki (Nano Tech Solutions), Mr. Anada (JFCC), Dr. Lars van der Wal (DENSsolutions) and Mr. Hirai (JEOL). Bottom row – from left to right: Mr. Fukunaga (JEOL), Mr. Jinbo (JEOL) and Mr. Hisada (JEOL).

We are proud to announce that DENSsolutions has installed another Climate system in Japan, at the Japan Fine Ceramics Center, located in Nagoya, a highly populated Japanese port city. In this article, we interview Dr. Satoshi Anada, Senior Researcher at the Nanostructures Research Lab in JFCC, to learn more about their microscopy facility, its research direction, as well as how our Climate system is advancing their research.

Can you tell me about Japan Fine Ceramics Center and its research and development initiatives?

Japan Fine Ceramics Center (JFCC) was established back in 1985, with the goal of improving the quality of fine ceramics mainly through integrated testing and evaluation systems. JFCC has numerous business activities, one of which is the research and development (R&D) of materials, manufacturing technology and evaluation technology. Our R&D initiatives are focused on obtaining technological solutions to problems related to the environment, energy and safety. We have two main laboratories: 1) the Materials R&D Lab and 2) the Nanostructures Research Lab. The Materials R&D Lab focuses on the development of highly functional and novel materials (mainly ceramics) by improved process control, whereas the Nanostructures Research Lab focuses on the development and enhancement of state-of-the-art electron microscopy and related technologies. At the Nanostructures Research Lab, we have a high-end electron microscope – the JEOL JEM-ARM300F2 Grand ARM. This microscope enables us to observe samples at ultra-high spatial resolution with highly sensitive analysis over a wide range of accelerating voltages.”

What type of applications are the users at the Nanostructures Research Lab interested in using the Climate G+ system for?

“Users at the Nanostructures Research Lab are interested in applying the DENSsolutions Climate system to record operando TEM observations of battery and catalyst materials. We aim to understand where and how reactions take place, and which conditions enhance the performance of those materials. Moreover, we are interested in the electrochemical oxidation of materials in reaction with oxidants such as oxygen and hydrogen.”

What particular features of the DENSsolutions Climate G+ system attracted you to the system? 

“In order to understand factors and mechanisms related to the performance of battery and catalyst materials, it is important to observe their reactions in the actual environments in which they are used. The Climate system has the ability to flexibly and rapidly adjust gas composition, temperature, flow and pressure, which enables us to observe our battery and catalyst materials under various experimental conditions. This is capability is particularly what attracted us to the solution.”

In your experience so far, how have you found working with the Climate G+ system?

“The preliminary processes including the assembly of the Climate Nano-Reactor and leak testing are quite straightforward, assisted by the well-established Climate manual and software. With the Climate system, we have been able to perform numerous experiments without running into any leakage issues. Moreover, we are particularly impressed with the stability of the system even at extremely high temperatures.”

Dr. Satoshi Anada
Senior Researcher | Japan Fine Ceramics Center

Dr. Satoshi Anada received his Ph.D. degree in Engineering, Material Science, from Osaka University. Previously, he was working as a Specially Appointed Assistant Professor in the Research Center for Ultra-High Voltage Electron Microscopy at Osaka University. Currently, Dr. Anada is working as a Senior Researcher in the Japan Fine Ceramics Center (JFCC). His research was focused on the electromagnetic analysis of functional materials and devices using transmission electron microscopy, and now particularly on different microscopic measurement informatics.

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Liquid flow control: Unlock untapped research capabilities within in situ LPEM

Liquid flow control: Unlock untapped research capabilities within in situ LPEM

Via the unique on-chip microfluidic channel of the DENSsolutions Stream system, researchers were able to create a highly controlled chemical environment for visualizing the nanoscale metallic electrodeposition of copper crystals.

Original article by Cheng et al.

Liquid phase transmission electron microscopy (LPTEM) enables the observation of time-resolved dynamics in liquid state at high spatial resolution. The technique has gained exponential popularity over the last decade, and has contributed greatly to a wide range of fields, including materials science, chemistry and life science. With LPEM, researchers can explore the dynamical evolution of key materials and uncover fundamental insights into nucleation and growth. Only in recent years have researchers been able to control the chemical environment within an in situ LPEM experiment, owing to the award-winning innovation that is the DENSsolutions Stream system. In a recent publication, researchers including Dr. Ningyan Cheng from Anhui University utilized the Stream system to visualize the metallic electrodeposition of copper crystals in a highly controlled chemical environment. This was made possible due to the unique on-chip flow channel of Stream, which enables numerous advantages such as the ability to flush away beam-induced species, explore flow-dependent liquid dynamics and easily change electrolyte composition.

On-chip microfluidic channel

The core of the DENSsolutions Stream system is our patented Nano-Cell, which consists of a top and bottom chip, together forming a sealed compartment that enables users to safely perform liquid experiments inside the TEM. The bottom chip contains spacers, an integrated liquid inlet, flow channel and an outlet. Via pressure-based pumps, a liquid sample can be driven from the inlet through the field of view and then through the outlet. This process is demonstrated in the video below. Importantly, users can independently control the pressure at the inlet and outlet of the Nano-Cell, and therefore the absolute pressure in the microfluidic channel. This then enables full control over the liquid flow rate within the cell.

Movie 1: Animation depicting the microfluidic channel of the Stream Nano-Cell

Efficient liquid flow

Before observing any liquid phenomena in the TEM, Dr. Cheng and her fellow collaborators first had to ensure that the flow was efficient and well-controlled. To do this, the researchers first assembled a dry Nano-Cell. The flow was then initiated by turning on the pressure-based pump, while keeping all imaging parameters constant. After 30 seconds, the imaging contrast changed abruptly, implying that the liquid had definitely flowed into the Nano-Cell. This process is shown in the video below. The time taken to completely fill the Nano-Cell ranges anywhere from tens of seconds to just 3 minutes when a flow rate of 8 μl/min is applied.

Movie 2: In situ TEM movie showing the liquid flow into the Nano-Cell in just 30 seconds

Removal of beam-induced species

A key benefit of controlling the liquid flow within an LPEM experiment is the ability to remove beam-induced particles. The researchers first generated particles by increasing the electron flux on purpose through changing the spot size from 5 to 1. The process of removing the beam-induced species in this experiment is detailed in the video below, with the direction of the flow going from top to bottom. As soon as the flow was cut off at 6.4s, the particles started to form and grow on the membrane. The flow was then switched on again at 11.7 seconds, which is when the particles that were stuck to the membrane started to peel off and move from the top to the bottom area in the field of view. It took just 2 minutes to fully flush away the particles, which is a reproducible process. The direction of the particles’ movement is the same as the direction of the flow (top to bottom), confirming the effectiveness and power of the liquid flow control. 

Movie 3: Removal of beam-induced species via liquid flow control

Capturing flow-dependent liquid dynamics

The next step for the researchers was to explore the effect of the flow rate on the electrochemical copper crystallization and dissolution processes in real time. They first observed the effect of using a higher flow rate of 1.4 μl/min on the Cu deposition and dissolution processes, which showed to be reversible. The protocol included the initial electrode cleaning, deposition (−0.9 V, 10 s), dissolution (+0.4 V, 15 s) and repeating the process for 4 cycles. As demonstrated in the video below, the researchers found that uniform copper deposition can be obtained at a higher liquid flow rate (~1.4 μl/min), whereas at a lower liquid flow rate (0.1 μl/min), the growth of copper dendrites was observed. 

Movie 4: Copper electrodeposition at a flow rate of 1.4 μl/min (left) and 0.1 μl/min (right)

Changing electrolyte composition

Besides exploring the effects of altering the flow rate, a major point of interest in this study was observing the effect of adding foreign ions, such as phosphates, on the electrodeposition. Such additives can affect the electrochemically deposited crystals by, for example, changing the nuclei structures. The researchers first studied the electrodeposition of copper from a pure CuSO₄ aqueous solution. In this case, no obvious dendritic morphology was observed and instead only granules were formed (see below Figure 1, Left).

After the experiment, the electrolyte in the sample source was replaced by a mixture of CuSO and KHPO solution. The liquid was kept flowing with a flow rate of 3 μl/min for 15 min, which enabled the researchers to directly study the electrolyte effect on the depositions in the same liquid cell by excluding all the uncertainties during different cell assembly. Contrastingly in this case, copper dendrites were observed to grow and the addition of HPO− ions in the electrolyte led to the formation of Cu-phosphate complexes (see Figure 1, Right). These results further confirm the importance of being able to modulate the electrolyte composition, and demonstrate the effectiveness of the environment control that Stream enables.

Figure 1: The effect of phosphate addition on Cu electrodeposition

Exploiting electrode design to alter the chemical environment

When studying Cu electrodeposition in the previous experiment, the researchers saw that dendrite formation can be further promoted by the in situ addition of foreign ions, such as phosphates. In order to confirm the generality of this technique, they also took a look at Zn electrodeposition in an aqueous solution of ZnSO. The figure below shows the total growth of the zinc layer at b) a lower potential of −0.9 V (versus Pt) in the first 10 seconds, and c) a higher potential of −1.1 V (versus Pt) in the next 10 seconds. In d) the total growth of the Zn depositions in the first 20 seconds is shown. The researchers observed in the first 10 seconds (−0.9 V) that the deposition on the inner edge is rougher compared to the outer edge. In the following growth at −1.1 V, dendritic depositions are nucleated and grown on the previous outer edge, while no further growth can be observed in the inner edge. This experiment demonstrates that the special electrode design of Stream enables the exploration of rich liquid dynamics within different chemical environments. 

Figure 2: Zinc electrodeposition in b) the first 10 seconds with a potential of −0.9 V and c) in the next 10 seconds with a potential of −1.1 V. d) shows the total Zn growth in the 20 seconds.


Through this study, it is shown that Stream’s distinctive ability to enable liquid flow control opens the doors for researchers to truly alter the chemical environment within the liquid cell. By controlling the liquid flow, a user can flush away beam-induced species, explore flow-dependent liquid dynamics and easily change electrolyte composition. Moreover, the unique design of the electrodes in the Stream system allows researchers to explore complex liquid dynamics within different chemical environments within the same liquid cell. Importantly, the direct observations made by Cheng et al. not only provide new insights into understanding the nucleation and growth, but also give guidelines for the design and synthesis of desired nanostructures for specific applications, such as high performance electrocatalysis for energy conversion and electrodes for secondary batteries. 

Hanglong Wu portrait

Image of Dr. Ningyan Cheng from Max-Planck-Institut für Eisenforschung GmbH

“The DENSsolutions Stream System not only provides a useful means to study a wide range of dynamics in solution, but also enables systematic studies of the effect of the chemical environment on the corresponding reactions through precise control of the flow rate, liquid composition and other significant parameters.” 

Prof. Dr. Ningyan Cheng   Associate Professor  |  Anhui University

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Climate helps uncover phase coexistence and structural dynamics of redox metal catalysts

Using our Climate system, scientists are able to interrelate the atomic-scale structural dynamics of redox metal catalysts to their activity.

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