All you need to know about the Nano Channel Chip

The world’s first of its kind – for use in TEM, SEM and optical microscopy

The Nano Channel Chip is based on 10 years of prof. Kristian Mølhave’s research and development at the Technical University of Denmark. It aims to introduce a higher level of reproducibility, resolution, flow control and ease-of-use than any other liquid-cell. The Nano Channel Chip fits in our holders for TEM (JEOL and TFS), SEM and optical microscopes.
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1

No assembly needed
The chip is made in one piece so there is simply nothing to assemble. There is no cleaning necessary either, as the inlets seal the chip and the internal channel system remains chemically clean until the membranes are broken by a flow through the chip. Prep-time is less than 5 minutes!

2

Well-defined liquid thickness down to 20 nm!
Membrane bulging is also not an issue. Each channel is 1-2 µm wide and therefore typically bulges less than 10 nm inside the TEM.

3

Silicon-nitride membranes down to 10 nm!
*Plus a 1-3 nm layer of Al2O3 which makes up all surfaces that are inside the channel system. This has enabled customers to consistently attain ~1 Å resolution of growth dynamics of gold crystals in the TEM.

4

Four individually controlled in/outlets in the chip
These four in/outlets create two bypass channels inside the chip. Two of them can be used as inlets, the other two as outlets. Being very large – 100 µm wide and 15 µm deep, liquids can be flushed into the chip in about a second and exchanged in just a few seconds.

5

Unprecedented flow control and mixing directly in the field of view
Two liquids from each bypass channel can be brought together in the field of view inside nano channels. The Nano Channel Chip is the first ever commercially available liquid cell that can mix directly in the field of view. Another benefit of the nano channels is that you will know exactly where the flow goes, since the channels are guiding the liquid exactly where you can see.

6

Robust and reliable
Because the chips are already assembled with a firm wafer-bond, the suspended membrane can withstand a lot. In fact, you can drop the chips and they will survive. Also, you will not have to worry about tightening the lid on top of the chip too much, the chip can withstand it. Finally, the vacuum is the most robust of any liquid holder. Because the chip is so robust, it can be pushed very hard against sealing O-rings by the lid, creating a strong and reliable seal.

ease of use

Assembly and Disassembly in minutes

The Nano Channel Chip is an innovative piece of technology that has been designed to streamline complex laboratory procedures. One of the key benefits of the Nano Channel Chip is its ease of use. The chip is incredibly simple to set up and can be used by anyone, regardless of their level of experience.

step 1

Screw off lid

step 2

Place the new chip in the holder

step 3

Screw on the lid again

step 4

Vacuum test holder and begin TEM session

Dr. Andy Stewart
University College London Studies proteins.
Customer‍
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"The chip design reduces the sample preparation time to 5 minutes”
- November 2022

Wide range of use

Use in TEM, SEM and optical microscopes

We make TEM holders for Thermo Fisher and JEOL, and our SEM holder can be used in optical microscopes as well. We make our own holders and accessories and will build custom solutions to ensure our equipment finds its right place in your lab.
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a true nano-fluidic flow cell for tem
and sem

The Nano Channel Chip turns a common microfluidic flow-cell structure into a truly nanofluidic one and makes it adaptable with electron microscopes. The chip has four inlets and an internal flow structure with two micron-sized bypass channels with nano channels connecting them. When a higher pressure is applied to one bypass channel, the liquid flows through the nano channels into the other bypass channel, and vice versa. Only the nano channels are visible in the field of view, whereas the larger micro/bypass channels are hidden away inside the chip to protect the TEM from leakage of a larger volume of liquid. The volume of a nano channel is on the order of femtoliters and poses no risk of breaking the vacuum in the column on its own. Even when a nano channel fractures during a TEM experiment, the column vacuum remains intact.

The four inlets are sealed with O-rings in the tip of the holder and held in place with a lid. Tubes connect inlet ports in the backside of the holder to each of the four inlets in the chip. From there, the holder can be controlled with syringes or a pressure-based pump system. For this, we recommend using Fluigent’s EZ Flow which can be used to control each inlet separately and precisely.
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THE TECH SPECS

Many Nano Channels in a large field of view

The chip has a large, suspended membrane, up to 1,250 x 200 µm, made of Silicon-Nitride. The entire membrane is electron transparent and visible in the TEM. Across this membrane are as many nano channels as we want, in any pattern, down to ~1 µm resolution. We use maskless lithography to make the channel patterns, so design changes are easy from batch to batch, and we can make any number of different designs in one batch. Different channel designs yield different types of flow in the channels, suitable for flushing out radiolysis, trapping particles, or mixing two liquids together in the field of view.

Filling, flowing, and mixing in the Nano Channel Chip

Filling
The Nano Channel Chip is mounted in a TEM or SEM holder in less than five minutes. From here, the holder can be placed in the microscope, tubes can be attached to the backside of it and liquids can be flown into the system. The channels are filled almost instantaneously as liquid comes into contact with the highly hydrophilic channel surfaces. Capillary forces on the order of 10 bar ‘suck’ in the liquid forcefully, ensuring a complete filling.
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Flowing
After the liquid has filled up the chip, the capillary forces are no longer acting on the liquid. From here, the pressure applied to the micro/bypass channels will determine the flow inside the channels: A larger pressure on one bypass channel will push the liquid through to the other bypass channel, and vice versa. It is impossible to see flow in the channels if there is nothing in them, moving. Therefore, to verify flow in the channels, we have often used nano particles which can be assumed to move precisely along with the liquid.
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Mixing
The two bypasses in the holder can be used to fill the chip with two different liquids that can come together via nano channels in the field of view. We have developed four mixing methods that depend on diffusion and flow in the channels. One of the methods involves simply letting the two liquids merge into a central channel as seen in the image here.
The other mixing methods are described in more detail in our product brochure which you can download here:
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DOWNLOAD NANO CHANNEL CHIP BROCHURE

But what about bubbles?
This is a question we get a lot and luckily the answer is good! Because bubbles are usually ‘squeezed’ out of the liquid and dissolve into it, exactly because of the large capillary pressure in the small nano channels. A video of the filling of channels, slowed down, can be seen on our LinkedIn page here. In this video, you can also see ‘dead-end’ channels being filled with water, trapping air/bubbles. However, within 10 seconds, most of these bubbles have disappeared.

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