Logo: University of Southern California

Advanced Materials

Mat 1

Polymeric Materials
We have several projects developing new polymeric materials with interesting behavior; for example, large non-linear optical coefficients or response to environmental stimuli.  The approaches focus on methods for synthesis which can directly attach (graft) the polymers to the surface of devices, thus enabling orientation of the polymers in a specific manner.
Silica Sol-gel Materials
We are currently studying ways to tailor the synthesis of sol-gel based optical glasses to control the optical properties to improve the final device characteristics.  This includes the addition of dopants to create lasers or high refractive index materials to manipulate light propagation. 
Nanoparticle Synthesis
Our efforts in nanoparticle synthesis are focused on two distinctly different applications: 1) the development of non-linear optical materials for integrated devices and 2) development of imaging agents.  Given this breadth, we are employing a wide range of synthesis methods and characterization techniques.
Surface Chemistry
As complementary work to our biological systems efforts, we have several projects investigating routes to efficiently and controllably attach and orient biomolecules to the surface of optical devices without degrading their optical performance.  We are exploring conventional routes and targeting strategies (eg NHS ester techniques) as well as developing methods of non-destructive removal and regeneration of the device surface.

 

 
Recent papers in this area: 
E. Gungor, A. M. Armani, "Photocleavage of covalently immobilized amphiphilic lock copolymer: From bi- to monolayer", Macromolecules (2016). in press
M. E. Lee, E. Gungor, A. M. Armani, "Photocleavage of poly(methyl acryclate) with centrally located o-Nitrobenzyl moiety: Influence of environment on kinetics", Macromolecules 48 (24), 8746-8751 (2015).
A. B. Socorro, S. Soltani, I. Del Villar, J. M. Corres, A. M. Armani, "Temperature sensor based on a hybrid ITO-silica resonant cavity", Optics Express 23 (3), 1930-1937 (2015). 
S. Mehrabani, A. J. Maker, A. M. Armani, "Hybrid integrated label-free chemical and biological sensors", Sensors 14 (4), 5890-5928 (2014).
N. Deka, A. J. Maker, A. M. Armani, "Titanium enhanced Raman microcavity laser", Optics Letters 39 (6), 1354-1357 (2014).
H. K. Hunt, A. M. Armani, "Bioconjugation strategies for label-free optical microcavity sensors" , IEEE Journal of Selected Topics in Quantum Electronics 20 (2), 6900213 (2014).
C. Shi, S. Soltani, A. M. Armani, "Gold nanorod plasmonic upconversion microlaser", Nano Letters 13 (12), 5827-5831 (2013).
A. J. Maker, A. M. Armani, "NanoWatt threshold, alumina sensitized neodymium laser integrated on silicon", Optics Express 21 (22), 27238-27245 (2013).
S. Mehrabani, A. M. Armani, "Blue upconversion laser based on thulium doped silica microcavity", Optics Letters 38 (21), 4346-4349 (2013).
S. Mehrabani, P. Kwong, M. Gupta, A. M. Armani, “Hybrid microcavity humidity sensor”, Applied Physics Letters 102, 241101 (2013).
A. J. Maker, B. A. Rose, A. M. Armani, “Tailoring the behavior of optical microcavities with high refractive index sol-gel coatings”, Optics Letters 37 (14), 2844-2846 (2012).
B. A. Rose, A. J. Maker, A. M. Armani, “Characterization of thermo-optic coefficient and material loss of high refractive index silica sol-gel films in the visible and near-IR”, Optical Materials Express 2 (5), 671-681 (2012).
C. Shi, H. -S. Choi, A. M. Armani, “Optical microcavities with a thiol-functionalized gold nanoparticle polymer thin film coating”, Applied Physics Letters, 100 (1), 013305 (2012). 
H. -S. Choi*, D. Neiroukh*, H. K. Hunt, A. M. Armani, “Thermo-optic coefficient of polyisobutylene ultrathin films measured with integrated photonic devices”,Langmuir 28 (1), 849-854 (2012). *authors contributed equally
L. M. Freeman, A. M. Armani, “Photobleaching of Cy5 conjugated lipid bilayers determined with optical microresonators”, Journal of Selected Topics in Quantum Electronics 19 (3), 1160-1165 (2012).
H. -S. Choi, S. Ismail, A. M. Armani, “Studying polymer thin films with hybrid optical microcavities”, Optics Letters 36 (11), 2152-2154 (2011).
L. M. Freeman, S. Li, Y. Dayani, H.-S. Choi, N. Malmstadt, A. M. Armani, “Excitation of Cy5 in self-assembled lipid bilayers using optical microresonators”, Applied Physics Letters 98 (15), 143703 (2011).
H. K. Hunt, A. M. Armani, “Recycling microcavity optical biosensors”, Optics Letters 36 (7), 1092-1094 (2011).
H.-S. Choi, A. M. Armani, “Thermal non-linear effects in hybrid optical microresonators”, Applied Physics Letters 97 (22), 223306 (2010).
H. K. Hunt, C. Soteropulos, A. M. Armani, “Bioconjugation strategies for microtoroidal optical resonators,” Sensors 10 (10), 9317 (2010).  (Special Issue on Optical Resonant Microsensors)
H.-S. Choi, X. Zhang, A. M. Armani, “Hybrid silica-polymer ultra-high-Q microresonators,” Optics Letters 35 (4), 459 (2010).
H.-S. Hsu, C. Cai, A. M. Armani, “Ultra-low-threshold Er:Yb sol-gel microlaser on silicon,” Optics Express 17 (25), 23265 (2009).