Optical Manipulation of Janus Particles Using Optical Nanofibers

Janus particles, which are small composite particles, are of interst for biomedical applications, where they act as actuators, carriers, or imaging agents. One major technical challenge is efficient manipulation of Janus particles. Long-range methods depending on chemical reactions or thermal gradients have limited precision and depend on the environmental fluid. Here, we demonstrate the optical manipulation of Janus particles consisting of silica microspheres half-coated with gold in the evanescent field of an optical nanofiber. The Janus particles have faster propulsion along the nanofiber compared to pure dielectric particles of the same size.