Discontinuous Dewetting, Template-Guided Self-Assembly, and Liquid Bridge-Transfer Printing of High-Resolution Single-Walled Carbon Nanotube Lines for Next-Generation Electrodes and Interconnects

A template-guided, self-assembly patterning technique called discontinuous dewetting (DD) and liquid bridge transfer (LBT) was applied to successfully pattern single-walled carbon nanotubes (SWCNTs): the first 1D nanomaterials patterned using the technique. The technique could efficiently and simply pattern SWCNTs with 2.5-10 μm resolution using little energy, low temperature (≤90 °C), and low cost and is potentially compatible with roll-to-roll manufacturing. Many variables were investigated to determine successful patterning conditions. The SWCNT patterning technique demonstrates the potential to obtain the often mutually exclusive properties for SWCNT patterning of high resolution and fast throughput/manufacturability. Due to the low concentration attainable in SWCNT dispersions, a preliminary wetting layer and evaporation-driven deposition were required to achieve a uniform and high-density deposition of SWCNTs inside the patterned cavities of a polydimethylsiloxane transfer stamp. The wetting layer allowed for uniform SWCNT deposition inside the cavities by preventing depinning of the SWCNT ink solution in the cavities. The wetting layer also doubled as a release layer during LBT, allowing easy transfer of the SWCNT lines onto hydrophilic substrates. SWCNT lines were patterned with widths down to 2.5 μm, up to centimeter lengths, and a resistivity of 1.9 × 10-3 ω m without any annealing. This work demonstrates the potential of DD and LBT patterning of SWCNTs for high-resolution R2R printing of cheap and/or flexible next-generation electrodes and interconnects.