An Optically Controlled Microscale Elevator Using Plasmonic Janus Particles.

ABSTRACT: In this article, we report how Janus particles, composed of a silica sphere with a gold half-shell, can be not only stably trapped by optical tweezers but also displaced controllably along the axis of the laser beam through a complex interplay between optical and thermal forces. Scattering forces orient the asymmetric particle, while strong absorption on the metal side induces a thermal gradient, resulting in particle motion. An increase in the laser power leads to an upward motion of the particle, while a decrease leads to a downward motion. We study this reversible axial displacement, including a hysteretic jump in the particle position that is a result of the complex pattern of a tightly focused laser beam structure above the focal plane. As a first application we simultaneously trap a

SUBMITTER: Nedev S 

PROVIDER: S-EPMC4416468 | biostudies-literature | 2015 Apr

REPOSITORIES: biostudies-literature