Chemical and Biochemical Engineering Publications
Document Type
Article
Publication Date
11-10-2023
Journal
ACS Applied Nano Materials
Volume
6
First Page
20769
Last Page
20781
URL with Digital Object Identifier
https://pubs.acs.org/doi/abs/10.1021/acsanm.3c03728
Abstract
Increasingly smaller fluid flow devices depend on increasing smaller sensors to operate. In this work, we develop a miniature wall shear stress sensor consisting of a pair of carbon nanotube pillars that produce a measurable capacitance change when one is deflected by the flow. The sensor, including material producing the capacitance signal, has a 50 µm x 60 µm footprint and < 200 µm height. It provides 0.05-1 fF/Pa sensitivity with up to ±8 Pa range. Most sensors produced were found to have a wider operating range when the thinner pillar was positioned downstream because greater deflection could be achieved without contact between the pillars. Interestingly, a small number of sensors responded differently to flow due to twisting of the sensing element rather than bending or due to a dominant Bernoulli effect. These diverse sensing mechanisms could be exploited to tune sensitivity or operating range in future designs.
Citation of this paper:
Julien B N, Holmes N, Ghode R G S, and Boutilier M S H. Wall shear stress sensors based on carbon nanotube pillars. ACS Applied Nano Materials 2023, 6, 20769–20781.
