JMEMS Letters Fabrication of Self-Sealed Circular Microfluidic Channels in Glass by Thermal Blowing Method

We report fabrication of circular glass microchannels with radius less than 100
$\mu \text{m}$
using the glass blowing technique. Silicon trenches filled with nitrogen are used for microchannel fabrication. We report an interesting reflow regime where the flowing glass fills the silicon trenches to form a completely circular microchannel. Circular microchannels have symmetric velocity profile and do not suffer from flow stagnation problems observed in rectangular channels. Besides circular shape, fabrication conditions of the semi-circular and elliptically shaped channels are also discussed. A mathematical model explaining the observation is also presented and is compared with the experimental results. [2021-0183]