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dc.contributor.authorAstley, Victoria
Reichel, Kimberly
Mendis, Rajind
Mittleman, Daniel M.
dc.date.accessioned 2015-01-06T19:20:33Z
dc.date.available 2015-01-06T19:20:33Z
dc.date.issued 2012
dc.identifier.citation Astley, Victoria, Reichel, Kimberly, Mendis, Rajind, et al.. "Terahertz Microfluidic Sensing Using a Parallel-plate Waveguide Sensor." Journal of Visualized Experiments?, 66, (2012) JoVE: e4304. http://dx.doi.org/10.3791/4304.
dc.identifier.urihttps://hdl.handle.net/1911/78893
dc.description.abstract Refractive index (RI) sensing is a powerful noninvasive and label-free sensing technique for the identification, detection and monitoring of microfluidic samples with a wide range of possible sensor designs such as interferometers and resonators [1,2]. Most of the existing RI sensing applications focus on biological materials in aqueous solutions in visible and IR frequencies, such as DNA hybridization and genome sequencing. At terahertz frequencies, applications include quality control, monitoring of industrial processes and sensing and detection applications involving nonpolar materials. Several potential designs for refractive index sensors in the terahertz regime exist, including photonic crystal waveguides [3], asymmetric splitring resonators [4], and photonic band gap structures integrated into parallel-plate waveguides [5]. Many of these designs are based on optical resonators such as rings or cavities. The resonant frequencies of these structures are dependent on the refractive index of the material in or around the resonator. By monitoring the shifts in resonant frequency the refractive index of a sample can be accurately measured and this in turn can be used to identify a material, monitor contamination or dilution, etc. The sensor design we use here is based on a simple parallel-plate waveguide [6,7]. A rectangular groove machined into one face acts as a resonant cavity (Figures 1 and 2). When terahertz radiation is coupled into the waveguide and propagates in the lowest-order transverse-electric (TE1) mode, the result is a single strong resonant feature with a tunable resonant frequency that is dependent on the geometry of the groove [6,8]. This groove can be filled with nonpolar liquid microfluidic samples which cause a shift in the observed resonant frequency that depends on the amount of liquid in the groove and its refractive index [9]. Our technique has an advantage over other terahertz techniques in its simplicity, both in fabrication and implementation, since the procedure can be accomplished with standard laboratory equipment without the need for a clean room or any special fabrication or experimental techniques. It can also be easily expanded to multichannel operation by the incorporation of multiple grooves [10]. In this video we will describe our complete experimental procedure, from the design of the sensor to the data analysis and determination of the sample refractive index.
dc.language.iso eng
dc.publisher JoVE
dc.rights Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
dc.title Terahertz Microfluidic Sensing Using a Parallel-plate Waveguide Sensor
dc.type Journal article
dc.contributor.funder National Science Foundation
dc.contributor.funder Air Force Research Laboratory
dc.citation.journalTitle Journal of Visualized Experiments?
dc.citation.volumeNumber 66
dc.type.dcmi Text
dc.identifier.doihttp://dx.doi.org/10.3791/4304
dc.identifier.pmcid PMC3486774
dc.identifier.pmid 22951593
dc.type.publication publisher version
dc.citation.firstpage e4304


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