Remarkable Conductive Anisotropy of Ag-Coated Glass Microbeads/UV Adhesive Composites Made by Electric Field Induced Alignment

Abstract

We successfully prepared highly anisotropic conductive composites (ACCs) made of Ag-coated glass microbeads/ UV adhesive via electric field-induced alignment, which was achieved using custom patterned microelectrode arrays. An optimized AC electric field (2 kV/cm, 1 kHz) with pole-plate spacing (50 μm) was utilized to effectively assemble the microbeads into chain arrays, which were precisely positioned on the microelectrode arrays to construct ordered conductive channels. In this case, tangling and cross-connection of the assembled microchains could be reduced, resulting in enhanced performance of the ACCs with high conductivity as well as excellent anisotropy. With a minor loading (3 wt %), the conductivity in the alignment direction could reach ∼24.9 S/m, which was the highest among the reported ACCs to the best of our knowledge, and it could also be 6 orders of magnitude higher than that within the plane. Besides, the samples exhibited high reliability in wire connections with low resistances. Due to these fascinating properties, the ACCs demonstrate promising applications for reliable electrical interconnects and integrated circuits.