High-Yield Bridged Assembly of ssDNA-Modified SWCNT Using Dielectrophoresis

Abstract

A high-yield, bridged assembly of single-walled carbon nanotubes (SWCNT) was demonstrated using single-strand DNA (ssDNA) modification, dielectrophoresis (DEP), and electroless deposition of gold. ssDNA modification is used for the mono-dispersion of an SWCNT solution for DEP. Gold deposition after DEP was used for the electrical and mechanical clamping of assembled SWCNTs. DEP conditions were investigated, and the best conditions, namely, 2 Vpp, 1 kHz, 1 min for 200-nm gap electrodes, resulted in 8 single-assembly and 19 multiple-assembly SWCNTs between 33 pairs of electrode gaps. The electrical properties of the assembled ssDNA-modified SWCNTs were measured as a back-gate type of FET, and both metallic and semiconducting properties were observed.