๐”– Bobbio Scriptorium
โœฆ   LIBER   โœฆ

Miniaturized thermal flow sensor with planar-integrated sensor structures on semicircular surface channels

โœ Scribed by M. Dijkstra; M.J. de Boer; J.W. Berenschot; T.S.J. Lammerink; R.J. Wiegerink; M. Elwenspoek


Publisher
Elsevier Science
Year
2008
Tongue
English
Weight
845 KB
Volume
143
Category
Article
ISSN
0924-4247

No coin nor oath required. For personal study only.

โœฆ Synopsis


A calorimetric miniaturized flow sensor was realized with a linear sensor response measured for water flow up to flow rates in the order of 300 nl min -1 . A versatile technological concept is used to realize a sensor with a thermally isolated freely suspended silicon-rich silicon-nitride microchannel directly below the substrate surface. The microchannel concept allows for the planar integration of sensor structures in close proximity to the fluid, while chemical-resistant fluidic connections can be made directly on top of the microchannel, without introducing large dead-volumes. The realized flow sensor consists of a microchannel with low hydraulic resistance and 4.5 nl total fluid volume. A pressure driven flow setup was used to force water through the microchannel, measuring output sensitivity in the order of 0.2 V/(nl min -1 ) for flows up to 300 nl min -1 . The measured sensor output is in close agreement with results obtained from both a detailed and an approximate numerical model of the sensor.