Thermal transpiration

In collaboration with EPFL, our group developed a silica-based aerogel Knudsen Pump prototype by combining a low temperature co-fired ceramic technology and sodium silicate based aerogels. Said samples have a tuneable pore size of 40-140 nm. The pore structure of the membrane with optimal pumping performance was verified by SEM microscopy. A test stand was constructed at EPFL and a temperature difference applied by resistive heating of the ceramic substrate and a flow rate density ~3.8 sccm/cm2 was reached. A comparison with other Knudsen pump membranes shows outstanding performance. [1]
[1] S. Zhao et al., Dimensional and Structural Control of Silica Aerogel Membranes for Miniaturized Motionless Gas Pumps, ACS Appl. Mater. Interfaces 7(33) (2015) 18803-18814.