title: Tunable Optical Nanoantennas Incorporating Bowtie Nanoantenna Arrays with Stimuli-Responsive Polymer.
abstract: We report on a temperature-responsive tunable plasmonic device that incorporates coupled bowtie nanoantenna arrays (BNAs) with a submicron-thick, thermosensitive hydrogel coating. The coupled plasmonic nanoparticles provide an intrinsically higher field enhancement than conventional individual nanoparticles. The favorable scaling of plasmonic dimers at the nanometer scale and ionic diffusion at the submicron scale is leveraged to achieve strong optical resonance and rapid hydrogel response, respectively. We demonstrate that the hydrogel-coated BNAs are able to sense environmental temperature variations. The phase transition of hydrogel leads to 16.2 nm of resonant wavelength shift for the hydrogel-coated BNAs, whereas only 3 nm for the uncoated counterpart. The response time of the device to temperature variations is only 250 ms, due to the small hydrogel thickness at the submicron scale. The demonstration of the ability of the device to tune its optical resonance in response to an environmental stimulus (here, temperature) suggests a possibility of making many other tunable plasmonic devices through the incorporation of coupled plasmonic nanostructures and various environmental-responsive hydrogels.
authors.affiliation: Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Qiugu
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Longju
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Yifei
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Peng
authors.initials: P
authors.lastname: Liu
authors.affiliation: Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Huawei
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Department of Aerospace Engineering, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Ma
authors.affiliation: Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Seval
authors.initials: S
authors.lastname: Oren
authors.affiliation: Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Edmond K C
authors.initials: EK
authors.lastname: Chow
authors.affiliation: Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011, USA.|Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Meng
authors.initials: M
authors.lastname: Lu
authors.affiliation: Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Liang
authors.initials: L
authors.lastname: Dong