Polymer nano nozzle fabricated by nanoscale electrohydrodynamic jet printing for high-resolution printing of low-viscosity inks

Electrohydrodynamic jet (E-jet) printing has emerged as a promising manufacturing technique in many areas due to its high efficiency, low cost, high resolution, and wide adaptability of materials. However, achieving further advancements in print resolution to the submicron and even nanoscale, particularly for low-viscosity inks with significant spread, requires nozzles with diameters in the hundreds of nanometers. It is particularly challenging and complicated to manufacture nozzles with such small diameters. In this paper, a concise method based on high-resolution E-jet printing was developed to fabricate nano-nozzles, which in turn enable high-resolution printing of a range of low-viscosity inks. First, the hybrid polymer nozzle mold consisting of BN303 nanomesa and SU-8 micromesa was fabricated by E-jet printing and ultraviolet (UV) lithography. Subsequently, the polymer nozzle was produced through a casting process of polydimethylsiloxane (PDMS) and subsequent bonding. In addition, the preliminary E-jet printing was performed with poly (3-hexylthiophene) (P3HT) ink using the polymer nozzle, resulting in lines as small as 140 nm. These outcomes demonstrate the compatibility of E-jet printing with high resolution and showcase the potential of the developed polymer nano-nozzles to significantly expand the scope of E-jet printing applications.