(35e) Mediating Fluidic Self-Assembly with Optical Traps

The placement of microscopic objects into desired orientations using only fluid phenomena?known as Fluidic self-assembly (FSA) ?has proven to be an effective approach for the parallel assembly of complex microsystems from smaller components of dissimilar materials. However, there is an interest in reducing the size of devices that can readily be assembled using FSA. Such advances would make FSA commonplace for nanosystems integration. Nanoscale phenomena that profoundly influence the motion of small particles include Brownian motion, shear induced migration, and electrolytic effects such as electric double layers. Mediating FSA with controllable external force fields offers means to elucidate multi-physics interference issues encountered during nanoscale assembly. Specifically, optical traps, or optical tweezers, can be used to induce forces which guide the FSA process. An investigation of FSA mediated with optical tweezers will be presented. Specifically, the ability to control the orientation and position of non-spherical particles during assembly will be explored. The presentation will include a theoretical description of the behavior of non-spherical particles trapped in an optical tweezers, as well as an experimental study of such behavior.