Extended-area optically induced organization of microparticles on a surface

Abstract

To extend beyond the limited field of view associated with optical tweezers, we implement a new geometry for lensless optical trapping (“LOT”). A Ronchi ruling is imaged at a sample interface beyond the critical angle for total internal reflection imposing local structure upon the optical fields. Due to the resulting transverse optical gradients, more than one thousand microparticles spanning 1mm2 were organized into microchannels that are entirely optical in origin. A generalized approach is presented, allowing for either guiding or stable trapping, as a function of the relative intensity of the counterpropagating surface waves.

Optically Controlled Cell Discrimination and Trapping Using Optoelectronic Tweezers

“…This limitation becomes more restrictive for larger particles, such as mammalian cells, which typically have diameters of approximately 10 µm. Other types of optical trapping, such as evanescent wave trapping [13], [14], are effective over larger areas but have a difficulty in isolating a single particle from a larger population.…”

Experimental Observation of Modulation Instability and Optical Spatial Soliton Arrays in Soft Condensed Matter

“…Transverse optical gradient forces due to the EW acting on particles in proximity to the supporting surface result in the accumulation of particles at the centre of the illuminated area, where the scattering forces due to the CP fields along the propagation (x) axis are balanced [17].…”

Speed enhancement of multi-particle chain in a traveling standing wave

“…This interaction is also called optical binding 7 and modifies the particles' equilibrium positions or can even create self-arranged structures of the particles. [8][9][10][11][12][13] In the case where multiple illuminated particles are in motion within the fluid, the hydrodynamic interactions take place which make the inter-particle interactions even more complex. 14 The hydrodynamic interactions between multiple particles have been also studied with the optical manipulation techniques for particles arranged into linear chains, 15,16 ring-like structures, [17][18][19][20] or two-dimensional matrix structures.…”