title: Long-range and rapid transport of individual nano-objects by a hybrid electrothermoplasmonic nanotweezer.
abstract: Plasmon-enhanced optical trapping is being actively studied to provide efficient manipulation of nanometre-sized objects. However, a long-standing issue with previously proposed solutions is how to controllably load the trap on-demand without relying on Brownian diffusion. Here, we show that the photo-induced heating of a nanoantenna in conjunction with an applied a.c. electric field can initiate rapid microscale fluid motion and particle transport with a velocity exceeding 10 μm s(-1), which is over two orders of magnitude faster than previously predicted. Our electrothermoplasmonic device enables on-demand long-range and rapid delivery of single nano-objects to specific plasmonic nanoantennas, where they can be trapped and even locked in place. We also present a physical model that elucidates the role of both heat-induced fluidic motion and plasmonic field enhancement in the plasmon-assisted optical trapping process. Finally, by applying a d.c. field or low-frequency a.c. field (below 10 Hz) while the particle is held in the trap by the gradient force, the trapped nano-objects can be immobilized into plasmonic hotspots, thereby providing the potential for effective low-power nanomanufacturing on-chip.
authors.affiliation: School of Electrical &Computer Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA.|Water Institute, Purdue University Calumet, Hammond, Indiana 46323, USA.
authors.forename: Justus C
authors.initials: JC
authors.lastname: Ndukaife
authors.affiliation: School of Electrical &Computer Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Kildishev
authors.affiliation: Water Institute, Purdue University Calumet, Hammond, Indiana 46323, USA.
authors.forename: Agbai George Agwu
authors.initials: AG
authors.lastname: Nnanna
authors.affiliation: School of Electrical &Computer Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Vladimir M
authors.initials: VM
authors.lastname: Shalaev
authors.affiliation: School of Mechanical Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Steven T
authors.initials: ST
authors.lastname: Wereley
authors.affiliation: School of Electrical &Computer Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, USA.|DTU Fotonik, Department of Photonics Engineering, Technical University of Denmark, Lyngby DK-2800, Denmark.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Boltasseva