Abstract
Liquid-core optofluidic waveguides based on total internal reflection of light were built in water-filled cylindrical microchannels fabricated in hydrophobic silica aerogels. Silica aerogels with densities ranging from 0.15 to 0.39 g/cm3 were produced by aging of alcogels in tetraethylorthosilicate solution for various time periods, followed by supercritical extraction of the solvent from the alcogel network. Subsequently, the resulting hydrophilic aerogel samples were made hydrophobic by hexamethyldisilazane vapor treatment. The synthesized samples retained their low refractive index (below ~1.09) and, hence, they could serve as suitable optical cladding materials for aqueous waveguide cores (refractive index n core = 1.33). Hydrophobic silica aerogel samples produced by the above technique also had low absorption coefficients in the visible part of the spectrum. Fabrication of microchannels in aerogel blocks by manual drilling preserving nanoporous and monolithic structure of aerogels was demonstrated for the first time. Long channels (up to ~7.5 cm) with varying geometries such as straight and inclined L-shaped channels could be fabricated. Multimode optofluidic waveguides prepared by filling the channels in the drilled aerogel monoliths with water yielded high numerical aperture values (~0.8). Efficient guiding of light by total internal reflection in the water-filled channels in aerogels was visually revealed and characterized by monitoring the channel output. The presented technique is expected to open up further possibilities for creating three-dimensional networks of liquid channels in aerogels for optofluidic applications.
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Monat C, Domachuk P, Eggleton BJ (2007) Integrated optofluidics: a new river of light. Nat Photon 1(2):106–114
Psaltis D, Quake SR, Yang C (2006) Developing optofluidic technology through the fusion of microfluidics and optics. Nature 442(7101):381–386
Pang L, Chen HM, Freeman LM, Fainman Y (2012) Optofluidic devices and applications in photonics, sensing and imaging. Lab Chip 12(19):3543–3551
Lei L, Wang N, Zhang XM, Tai Q, Tsai DP, Chan HL (2010) Optofluidic planar reactors for photocatalytic water treatment using solar energy. Biomicrofluidics 4(4):43004
Erickson D, Sinton D, Psaltis D (2011) Optofluidics for energy applications. Nat Photon 5(10):583–590
Korampally V, Mukherjee S, Hossain M, Manor R, Yun M, Gangopadhyay K, Polo-Parada L, Gangopadhyay S (2009) Development of a miniaturized liquid core waveguide system with nanoporous dielectric cladding—A potential biosensing platform. IEEE Sens J 9(12):1711–1718
Manor R, Datta A, Ahmad I, Holtz M, Gangopadhyay S, Dallas T (2003) Microfabrication and characterization of liquid core waveguide glass channels coated with Teflon AF. IEEE Sens J 3(6):687–692
Parks JW, Schmidt H (2016) Flexible optofluidic waveguide platform with multi-dimensional reconfigurability. Sci Rep 6:33008
Cristiano MBC, Christiano JSdM, Eliane MdS, Alexandre B, Jackson SKO, Tilon F, Giancarlo C, Alfredo RV, Carlos HBC (2007) Towards practical liquid and gas sensing with photonic crystal fibres: side access to the fibre microstructure and single-mode liquid-core fibre. Meas Sci Technol 18(10):3075
Fan X, White IM (2011) Optofluidic microsystems for chemical and biological analysis. Nat photonic 5(10):591–597
Ozcelik D, Parks JW, Wall TA, Stott MA, Cai H, Parks JW, Hawkins AR, Schmidt H (2015) Optofluidic wavelength division multiplexing for single-virus detection. Proc Natl Acad Sci U S A 112(42):12933–12937
Ellis PS, Gentle BS, Grace MR, McKelvie ID (2009) A versatile total internal reflection photometric detection cell for flow analysis. Talanta 79(3):830–835
Shih-Hao H, Fan-Gang T (2005) Development of a monolithic total internal reflection-based biochip utilizing a microprism array for fluorescence sensing. J Micromech Microeng 15(12):2235
Jung JH, Lee KS, Im S, Destgeer G, Ha BH, Park J, Sung HJ (2016) Photosynthesis of cyanobacteria in a miniaturized optofluidic waveguide platform. RSC Adv 6(14):11081–11087
Ramachandran S, Cohen DA, Quist AP, Lal R (2013) High performance, LED powered, waveguide based total internal reflection microscopy. Sci Rep 3:2133
Dallas T, Dasgupta PK (2004) Light at the end of the tunnel: recent analytical applications of liquid-core waveguides. Trends Anal Chem 23(5):385–392
Schelle B, Dreß P, Franke H, Klein KF, Slupek J (1999) Physical characterization of lightguide capillary cells. J Phys D Appl Phys 32(24):3157
Bernini R, Campopiano S, Zeni L, Sarro PM (2004) ARROW optical waveguides based sensors. Sens Actuators B Chem 100(1–2):143–146
Hawkins AR, Schmidt H (2007) Optofluidic waveguides: II. Fabrication and structures. Microfluid Nanofluidics 4(1–2):17–32
Özbakır Y, Jonas A, Kiraz A, Erkey C (2017) Aerogels for optofluidic waveguides. Micromachines 8(4):98
Schmidt H, Hawkins AR (2008) Optofluidic waveguides: I. Concepts and implementations. Microfluid Nanofluidics 4(1):3–16
Hawkins AR, Schmidt H (2008) Optofluidic waveguides: II. Fabrication and structures. Microfluid Nanofluidics 4(1):17–32
Yalizay B, Morova Y, Dincer K, Ozbakir Y, Jonas A, Erkey C, Kiraz A, Akturk S (2015) Versatile liquid-core optofluidic waveguides fabricated in hydrophobic silica aerogels by femtosecond-laser ablation. Opt Mater 47:478–483
Datta A, In-Yong E, Dhar A, Kuban P, Manor R, Ahmad I, Gangopadhyay S, Dallas T, Holtz M, Temkin H, Dasgupta PK (2003) Microfabrication and characterization of teflon AF-coated liquid core waveguide channels in silicon. IEEE Sens J 3(6):788–795
Wu CW, Gong GC (2008) Fabrication of PDMS-based nitrite sensors using Teflon AF coating microchannels. IEEE Sens J 8(5):465–469. doi:10.1109/JSEN.2008.918201
Cho SH, Godin J, Lo YH (2009) Optofluidic waveguides in Teflon AF-coated PDMS microfluidic channels. IEEE Photon Technol Lett 21(15):1057–1059
Datta A, Eom IY, Dhar A, Kuban P, Manor R, Ahmad I, Gangopadhyay S, Dallas T, Holtz M, Temkin F, Dasgupta PK (2003) Microfabrication and characterization of Teflon AF-coated liquid core waveguide channels in silicon. IEEE Sens J 3(6):788–795
Hüsing N, Schubert U (1998) Aerogels—Airy Materials: chemistry, structure, and properties. Angew Chem Int Ed 37(1–2):22–45
Du A, Zhou B, Zhang ZH, Shen J (2013) A special material or a new state of matter: a review and reconsideration of the aerogel. Materials 6(3):941–968. doi:10.3390/ma6030941
Bellunato T, Calvi M, Matteuzzi C, Musy M, Perego DL, Storaci B (2007) Refractive index dispersion law of silica aerogel. Eur Phys J C 52(3):759–764
Xiao L, Birks TA (2011) Optofluidic microchannels in aerogel. Opt Lett 36(16):3275–3277
Eris G, Sanli D, Ulker Z, Bozbag SE, Jonás A, Kiraz A, Erkey C (2013) Three-dimensional optofluidic waveguides in hydrophobic silica aerogels via supercritical fluid processing. J Supercrit Fluids 73:28–33
Bian Q, Chen S, Kim B-T, Leventis N, Lu H, Chang Z, Lei S (2011) Micromachining of polyurea aerogel using femtosecond laser pulses. J Non-Cryst Solids 357(1):186–193
Issa NA (2004) High numerical aperture in multimode microstructured optical fibers. Appl Opt 43(33):6191–6197
Djouadi D, Meddouri M, Chelouche A (2014) Structural and optical characterizations of ZnO aerogel nanopowder synthesized from zinc acetate ethanolic solution. Opt Mater 37:567–571
Thorlabs (1999) Optical Substrates. Accessed 16 November 2017
Riedel D, Castex MC (1999) Effective absorption coefficient measurements in PMMA and PTFE by clean ablation process with a coherent VUV source at 125 nm. Appl Phys A 69(4):375–380
Thorlabs (1999) Multimode Fiber Optic Patch Cables. Accessed 16 November 2017
Pope RM, Fry ES (1997) Absorption spectrum (380–700 nm) of pure water. II. Integrating cavity measurements. Appl Opt 36(33):8710–8723
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We thank KUYTAM (Koç University Surface Science and Technology Center) and KUTEM (Koç University TÜPRAŞ Energy Center) for their support.
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Özbakır, Y., Jonáš, A., Kiraz, A. et al. Total internal reflection-based optofluidic waveguides fabricated in aerogels. J Sol-Gel Sci Technol 84, 522–534 (2017). https://doi.org/10.1007/s10971-017-4426-8
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DOI: https://doi.org/10.1007/s10971-017-4426-8