Ordered arrays of nanoparticles often have interesting collective function relevant for applications like opto-electronic devices, optical cloaking, and metamaterials. The collective function of nanoparticle assemblies can be tuned by controlling the hierarchical structure of nanoparticle arrays, which is ultimately dictated by the driving forces of the assembly. The application of electric fields is particularly useful for directing nanoparticle assemblies because it allows for real-time control over the electric field-induced driving forces. Reconfigurable particle assemblies can be achieved by adjusting the electric field parameters or toggling the field on and off. Here, we implement lithographically patterned features and electrode geometries to direct the nanoparticles to areas of high or low field gradient by dielectrophoresis (DEP). Partially etched nanowires (PENs), consisting of alternating metallic and solvent-filled etch segments encased in a silica shell, are practically relevant for applications like reconfigurable metamaterials, but have complicated assembly behavior relative to the metal and dielectric particles typically assembled by DEP. To elucidate the design structure-assembly behavior relationship, we investigated the effect of various design parameters such as metallic segment length and spacing, total volume of metal, metal to dielectric volume ratio, and the number of metallic and etch segments on the collective assembly organization at different electric field conditions. Rationally designing the striping pattern can aid the realization of desired hierarchal structures, which is extremely useful for applications like reconfigurable devices.

Reconfigurable electric field directed nanoparticle assembly

254th National Meeting (2017)

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