“We are in the process of building a Micro-and-Nano-Technology Hub here in Basel”

What is the Cleanroom Facility doing, and which services is it offering?

A small Cleanroom Facility is in the basement of the current location. What you can do here is micro- and nanofabrication, i.e., fabricating devices with very small features, in the range of micro- and nanometres. The room is clean enough that no dust falls on your structure during fabrication or during photolithography.
The current Cleanroom is also open to external users, meaning that in addition to every D-BSSE group also external researchers are welcome. The facility is, however, based on user initiative and expertise. Potential users should not expect services but need training to gain the necessary expertise before using the facility for research. New users get an introduction by the Cleanroom staff but then they need to train in their respective groups and receive tutoring from experienced users, postdocs or doctoral students, who already have the necessary expertise.

Why is it called ‘Cleanroom’ and not, for example, ‘Chip manufacturing room’? Can you say a few words about the cleanroom environment, and how do people work in this Facility..?

Yes, to be clear it is not only for chip manufacturing, it can be basically everything at small scale that can be manufactured in the Cleanroom, including silicon chips, microfluidic plastic chips, any device that requires very small dimensions. Such device fabrication is very sensitive to pollution during fabrication. There are international standards for Cleanrooms, and we have the so called 100 and 1’000 cleanliness-level which corresponds to ISO-5 and ISO-7, with ISO-5 being the cleaner level underneath the laminar flow with less than 100 particles of a size larger than 0.5 micron (µm) per cubic foot. In the remaining Cleanroom Facility, we have ISO-7, meaning less than 10’000 particles larger than 0.5 micron per cubic foot. The air needs to be constantly filtered, clean air pumped in and the dirty air sucked out at the bottom. The complete volume of air in the Cleanroom Facility is being replenished about 20 times per hour. Before entering the Cleanroom Facility, you have to suit up, i.e., you have to make sure that you wear a suit, specific shoes, gloves and a cap. This is necessary, because any flake of skin or hair that falls on devices that are being manufactured is way larger than the dimensions of the devices that we are fabricating. Device features are in the order of half a micrometre while the diameter of a human hair is > 20 micrometre!

Can you provide some examples from research?

There are mostly two D-BSSE groups currently using the Facility, and single researchers from other groups such as the Schroeder, Müller and Panke groups. But, basically it is our group and the Bioanalytics group of Petra Dittrich. In most cases, research projects include the fabrication of microfluidic chips, i.e., chips with channels or chambers on the order of tens of micrometres. Features with which you can analyse single cells. Petra produces chips where she essentially encages single cells by pneumatically actuating walls that then surround the cells. In such a single-cell compartment you can then conduct chemical experiments. Or you can enclose bacteria and add antibiotics, and you then look at how long those bacteria survive, in other words: how effective the antibiotics are. In my group we work with microelectronic structures, so called CMOS, Complimentary Metal-Oxide Semiconductor, structures with a transistor gate lengths of 180 nanometres, which requires extremely high cleanliness.

The Cleanroom will triple in size at the new building. Why is that, what are the plans for its extension?

When we moved to Basel, the original idea was to bring engineering expertise to Basel. And this initiative included a large-enough Cleanroom, which could be used by all researchers in the Basel area who will want to process their micro- and nano-sized devices. Of course, our prime partner is the University of Basel and the external pageSwiss Nano-Institute, SNIcall_made, which will rent some space in the Cleanroom. They also bring in some equipment and they will collaborate with us on different technologies. We bring in mostly the microtechnology, the SNI adds the nanotechnology. We will also bring in a new focused ion beam (FIB) combined with an electron microscope, which is arriving these days. So, the Cleanroom is a synergistic effort of the University of Basel and us. Of course, also industry is invited and welcome to use the Cleanroom Facility. Roche already indicated interest in using the Cleanroom, in particular its Institute of Translational Biology, for processing microfluidic and other micro-devices. Also, other departments of the University of Basel stated their interest, including groups at the Biocenter, for example for making microfluidic devices. Same holds for the FHNW, the Fachhochschule Nordwest-Schweiz. But we are open to new collaboration partners. The vision is to establish a Micro-and-Nano-Technology Hub in Basel, jointly used by academic and industrial partners. There are of course other types of cleanrooms already established in Basel, those that are used in the pharmaceutical industry. The biggest difference between a Biology Cleanroom and a Micro-tech Cleanroom is that in the latter you have an overpressure, i.e., you don’t want anything to get into the Cleanroom whereas in the Biology-Cleanroom you have an underpressure because you don’t want anything to get out. Overall, we believe that the Micro-and-Nano-Technology Hub we currently build in Basel will meet a growing demand.

Thank you, Andreas, for giving us this insight on the Cleanroom and its future set-up.