@article{wee_hackney_wells_bradford_peters_2020, title={Ultrasonic Lamb wave measurement sensitivity of aligned carbon nanotube coated fiber Bragg grating}, volume={2}, ISSN={["2515-7647"]}, DOI={10.1088/2515-7647/ab525e}, abstractNote={Abstract}, number={1}, journal={JOURNAL OF PHYSICS-PHOTONICS}, author={Wee, Junghyun and Hackney, Drew and Wells, Brian and Bradford, Philip D. and Peters, Kara}, year={2020}, month={Jan} }
 @article{wee_wells_hackney_bradford_peters_2016, title={Increasing signal amplitude in fiber Bragg grating detection of Lamb waves using remote bonding}, volume={55}, ISSN={["2155-3165"]}, DOI={10.1364/ao.55.005564}, abstractNote={Networks of fiber Bragg grating (FBG) sensors can serve as structural health monitoring systems for large-scale structures based on the collection of ultrasonic waves. The demodulation of structural Lamb waves using FBG sensors requires a high signal-to-noise ratio because the Lamb waves are of low amplitudes. This paper compares the signal transfer amplitudes between two adhesive mounting configurations for an FBG to detect Lamb waves propagating in an aluminum plate: a directly bonded FBG and a remotely bonded FBG. In the directly bonded FBG case, the Lamb waves create in-plane and out-of-plane displacements, which are transferred through the adhesive bond and detected by the FBG sensor. In the remotely bonded FBG case, the Lamb waves are converted into longitudinal and flexural traveling waves in the optical fiber at the adhesive bond, which propagate through the optical fiber and are detected by the FBG sensor. A theoretical prediction of overall signal attenuation also is performed, which is the combination of material attenuation in the plate and optical fiber and attenuation due to wave spreading in the plate. The experimental results demonstrate that remote bonding of the FBG significantly increases the signal amplitude measured by the FBG.}, number={21}, journal={APPLIED OPTICS}, author={Wee, Junghyun and Wells, Brian and Hackney, Drew and Bradford, Philip and Peters, Kara}, year={2016}, month={Jul}, pages={5564–5569} }
 @article{wee_hackney_peters_wells_bradford_2016, title={Sensitivity of contact-free fiber Bragg grating sensors to ultrasonic Lamb waves}, volume={9803}, ISSN={["1996-756X"]}, DOI={10.1117/12.2218924}, abstractNote={Networks of fiber Bragg grating (FBG) sensors can serve as structural health monitoring (SHM) systems for large-scale structures based on the collection of ultrasonic waves. The demodulation of structural Lamb waves requires a high signal-to-noise ratio because Lamb waves have a low amplitude. This paper investigates the signal transfer between Lamb waves propagating in an aluminum plate collected by an optical fiber containing a FBG. The fiber is bonded to the plate at locations away from the FBG. The Lamb waves are converted into longitudinal and flexural traveling waves propagating along the optical fiber, which are then transmitted to the Bragg grating. The signal wave amplitude is measured for different distances between the bond location and the Bragg grating. Bonding the optical fiber away from the FBG location and closer to the signal source produces a significant increase in signal amplitude, here measured to be 5.1 times that of bonding the Bragg grating itself. The arrival time of the different measured wave coupling paths are also calculated theoretically, verifying the source of the measured signals. The effect of the bond length to Lamb wavelength ratio is investigated, showing a peak response as the bond length is reduced compared to the wavelength. This study demonstrates that coupling Lamb waves into guided traveling waves in an optical fiber away from the FBG increases the signal-to-noise ratio of Lamb wave detection, as compared to direct transfer of the Lamb wave to the optical fiber at the location of the FBG.}, journal={SENSORS AND SMART STRUCTURES TECHNOLOGIES FOR CIVIL, MECHANICAL, AND AEROSPACE SYSTEMS 2016}, author={Wee, Junghyun and Hackney, Drew and Peters, Kara and Wells, Brian and Bradford, Philip}, year={2016} }
 @article{stano_faraji_hodges_yildiz_wells_akyildiz_zhao_jur_bradford_2016, title={Ultralight Interconnected Metal Oxide Nanotube Networks}, volume={12}, ISSN={["1613-6829"]}, DOI={10.1002/smll.201503267}, abstractNote={Record-breaking ultralow density aluminum oxide structures are prepared using a novel templating technique. The alumina structures are unique in that they are comprised by highly aligned and interconnected nanotubes yielding anisotropic behavior. Large-scale network structures with complex form-factors can easily be made using this technique. The application of the low density networks as humidity sensing materials as well as thermal insulation is demonstrated.}, number={18}, journal={SMALL}, author={Stano, Kelly L. and Faraji, Shaghayegh and Hodges, Ryan and Yildiz, Ozkan and Wells, Brian and Akyildiz, Halil I. and Zhao, Junjie and Jur, Jesse and Bradford, Philip D.}, year={2016}, month={May}, pages={2432–2438} }