Monday, 1st of September 2014 I went to visit GaudiLabs in Lucerne to try and find a DIY solution to produce precise microfluidics, We wanted to try and reproduce the design of the Mother Machine (“Robust Growth of Escherichia Coli, P.Wang, L. Robert) or the compact portable biosensor from the microsystems laboratory of EPFL and HES-SO Wallis. Therefore our aim was to try and test the precision of DIY microfluidics. What was the minimal size of the channel that could easily be made.
We started first by listing the different methods that are possible to do DIY microfluidics.
- Cutting out a simple channel with a cutter in some double sided scotch, then putting something on it to seal it
- Use scotch again, but this time we can laser cut it.
- We can also laser cut the negative of the channels and make a PDMS chip
- It is possible to use a metal mold to print the circuit in the plastic of an old DVD, a technique similar to lithography.
- Nail Studio microfluidics
As we are looking for a precise, cheap and simple method, we chose to experiment with the nail studio microfluidics. We spent the afternoon testing the right combination of UV exposure, cleaning of the glass slate, heating of the slate etc.. We tried two different UV methods for the curing of the gel. The first was a basic UV lamp that you find in nail studios where you could adjust the number of UV lamps and the exposure time. The other method was a device that Urs built that used a UV lamp and a lens where the strength of the light and the exposure time where kept constant (3W Led at 1.5 W during 22 seconds)..Our best results were made using the homemade device.
After a few tests we concluded that we were missing an element because the nail polish would not stick enough to the glass slates. To try and adjust this we went to a nail salon and bought some nail primer. The sticking became much better but sadly the primer clouded the slate and it was harder to see through the glass slate.
We are not done yet working with microfluidics, we will try producing the chips in the lab at EPFL and in our DIY lab and compare precisely the precision of the DIY device!