Single Channel 20 nm membrane breakage…
There is a reliability/handling issue with the single slot chips. 0.5 mm x 10 mm slots, 20 nm thick membranes with 40 nm SiN reinforcement.
The membranes are easily packaged in an upper fluidic PDMS layer with inlet/outlets and two PDMS struts (on the membrane side to protect from accidental contact breakage.) The first test was done by connecting the piezo pump to the inlet and pumping DI water with the membrane side dry. While pumping (~5 to 6 µL/min) was successful at first, the membrane soon broke, leaking water.
The next test was done using Methynol. The device was placed in a petri dish of methynol. The inlet of the pump was connected to a methynol flled syringe in a syringe pump. Again, pumping (5.6 µL/min) through the channel was at first successful, the fluid edge was observed moving in the channel. And again the membrane broke.
So far this has been done with out the aid of a microscope to observe the membrane in situ. The next try will fix the device to a glass slide, which will be wetted, and will also use a three way valve at the pump end to help eliminate bubbles. If I can observe the breakage as it occurs I should be much closer to determining what is the cause.
