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Silicon based microfluidic cell for terahertz frequencies

Baragwanath, A.J.; Swift, G.P.; Dai, D.; Gallant, A.J.; Chamberlain, J.M.

Silicon based microfluidic cell for terahertz frequencies Thumbnail


A.J. Baragwanath

D. Dai

J.M. Chamberlain


We present a detailed analysis of the design, fabrication and testing of a silicon based, microfluidic cell, for transmission terahertz time-domain spectroscopy. The sensitivity of the device is tested through a range of experiments involving primary alcohol/water mixtures. The dielectric properties of these solutions are subsequently extracted using a Nelder–Mead search algorithm, and are in good agreement with literature values obtained via alternative techniques. Quantities in the order of 2 μmol can be easily distinguished for primary alcohols in solution, even with the subwavelength optical path lengths used. A further display of the device sensitivity is shown through the analysis of commercial whiskeys, where there are clear, detectable differences between samples. Slight absorption variations were identified between samples of the same commercial brand, owing to a 2.5% difference in their alcoholic content. Results from data taken on subsequent days after system realignment are also presented, confirming the robustness of the technique, and the data extraction algorithm used. One final experiment, showing the possible use of this device to analyze aqueous biological samples is detailed; where biotin, a molecule known for its specific terahertz absorptions, is analyzed in solution. The device sensitivity is once again displayed, where quantities of 3 nmol can be clearly detected between samples.

Journal Article Type Article
Publication Date Jul 1, 2010
Deposit Date Sep 2, 2010
Publicly Available Date Oct 9, 2012
Journal Journal of Applied Physics
Print ISSN 0021-8979
Electronic ISSN 1089-7550
Publisher American Institute of Physics
Peer Reviewed Peer Reviewed
Volume 108
Issue 1
Article Number 013102
Keywords Elemental semiconductors, Microfluidics, Microwave generation, Microwave spectroscopy, Silicon, Terahertz waves, Time-domain reflectometry.
Public URL


Published Journal Article (1.4 Mb)

Copyright Statement
© 2010 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Baragwanath, A.J. and Swift, G.P. and Dai, D. and Gallant, A.J. and Chamberlain, J.M. (2010) 'Silicon based microfluidic cell for terahertz frequencies.', Journal of applied physics., 108 (1), 013102 and may be found at

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