Optofluidic vortex arrays generated by graphene oxide for tweezers, motors and self-assembly

Abstract

Manipulating large numbers of a variety of particles/wires is essential for many lab-on-a-chip technologies. Here we generate a planar array of optofluidic vortices with photothermal gradients from an easy-fabricated graphene oxide (GO) heater to achieve high-throughput and multiform manipulation at low excitation power and low loss. As a tweezer, each vortex can rapidly capture and confine particles without restrictions on shapes and materials. The stiffness of the confinement is easily tuned by adjusting the vortex dimension. As a motor, it can actuate any traps to persistently rotate/spin in clockwise or anti-clockwise mode. As a high-performance 'workshop', this work lays the groundwork for various self-assembly ranging from colloid-based clusters, chains, capsules, shells and ultra-thin films, through particles' surface modification and fusion, to nanowire-based architectures. Furthermore, we can create multiple vortex arrays through fabricating an array of heaters, which enables massively parallel manipulation and distributed operations all on a chip.

Dumbbell Fluidic Tweezers for Dynamical Trapping and Selective Transport of Microobjects

“…To our interest, another noncontact approach, hydrodynamic tweezers (HT), achieves particle trapping through frequency‐dependent steady streaming induced by fluid oscillation near microfabricated geometries such as cylindrical obstructions, and wall protrusions or cavities . In comparison with the conventional OT, MT, and DEP techniques, HT and some other similar techniques provide a noninvasive means to manipulate cells or microorganisms in low Reynolds number flow utilizing gentle but robust microeddies . Nevertheless, due to the geometric restrictions for HT to trap particles, only static immobilization is possible, and selective transport of individual microobjects is still unlikely to be realized by HT.…”

Area cooling enables thermal positioning and manipulation of single cells

“…The first is the trade-off between temperature and thermal diffusion. Generally, the particle manipulation forces are from thermal convection, thermocapillary convection, and thermophoresis, [24][25][26] all of which have a positive relationship with temperature. High temperature means there is a strong manipulating force to steer different kinds of objects.…”

Evolution Behavior of Mixed Higher Order Optical Vortex–Edge Dislocations Propagating Through Atmospheric Turbulence

“…The light intensity of the field of phase singularities is zero. Because of the importance of the theory and its application in optical communications [4]- [8], optical tweezers [9], [10], optical manipulation and trapping of small particles [11]- [14] and quantum information processing [15], [16], it has aroused widespread interest among scholars. Wang reported the advances in optical communications using optical vortices [4].…”