Revolutionary flow sensor by surface channel technology

Why did you start this new product development?

“Surface channel technology was developed at the University of Twente around 2007. This technology has been a typical example of the use of semiconductor processes to minimize systems - flow sensors in our case. It was not until 2013 that I delved deeper into this matter, with the intention to make a marketable product out of this unique technology.”

“In 2020, I started a development project with several R&D colleagues. Our team had access to the Nanolab of the University of Twente, involved in the manufacturing of the through chip sensors. In cooperation with PHIX Photonics Assembly, we were able to ‘pack’ the chips into a robust sensor module.

And on April 5 there it was…  Bronkhorst introduced the FLEXI-FLOW to the world; a successful example of a unique academic technology converted into a marketable product.”
 
Let’s have a look at the technology…

Can you tell something about the capillary flow sensor?

“The heart of the FLEXI-FLOW mass flow instrument is a capillary flow sensor, mounted as a bypass to the main gas flow channel. Essentially, this sensor consists of two straight silicon nitride capillaries, each with a diameter of 100 micron and a wall thickness of 1 micron. Temperature-dependent metal resistors on top act as heaters and temperature sensors.
During operation, gas enters the capillaries, is heated by the heaters, and subsequently the temperature of the gas is measured at a defined position downstream. Flowing gas transports this heat, and in the laminar flow regime inside the capillaries, the temperature difference (or its voltage difference analogy) is a direct measure of the gas flow rate.”
 
“This flow sensor is patented by Bronkhorst and is called Trough Chip Sensor – TCS technology. It offers a fast and stable flow sensor applied in a proven bypass construction for a reliable and accurate flow measurement. It replaces the traditional capillary tube sensor. The slogan of the FLEXI-FLOW refers to this as well; swift & stable, proven & precise.”

How can users benefit from an instrument using this flow sensor?

Fast response time

Cooperation with University of Twente

“In the nineteen eighties, the Sensors and Actuators Research Unit of the University of Twente laid a solid foundation for ‘micro technology’. Miniaturization had already become an important trend for lab applications, and flow sensors were no exception. In 1990, Theo Lammerink successfully concluded his PhD research project on MEMS thermal flow sensors at the University of Twente – laying the basis for the eventual development of surface channel technology.

About the same time, the first contacts between the university and Bronkhorst arose. Joost Lötters and Wybren Jouwsma visited the university and started talking about this matter.
The start of developing a marketable product… FLEXI-FLOW.”