Manipulating and Patterning Micro/Nanoparticles in Liquid Using Multimode Membrane Resonators

We report on the experimental exploration of manipulating and patterning micro- and nanoparticles through engineering a micro mechanical resonating membrane platform that operates in liquid. By exploiting the Chladni figures effect, we demonstrate that particles (such as silver nanobeads, silicon oxide micro- and nanobeads, polyethylene microbeads) dispersed on top of the rectangular vibrating membranes can organize into diverse cluster patterns, in response to the devices' multimode resonances in liquid. These particles (-10nm-l0μm in diameters) are observed to aggregate at the antinodes of each mode within seconds, and controlling the excitation frequency can spatially reconfigure the particle assembly in situ. Computational results support the experimental observations and elucidate that the boundary streaming dominates the particle aggregation at the antinodal locations. Further, we realize a 3×3 array of square membranes to demonstrate parallel patterning on the same chip, exemplifying the scalability of this microdevice technology.