Optical vortex fabrication the electroconductive microdot with close-packed gold nanoparticles (Conference Presentation)

Abstract

Laser-induced forward transfer, a nozzle-free direct printing technology, enables the direct print of various donor materials, such as solids, high viscosity liquids with functional nanoparticles at high density, and even biomaterials, on a receiver owing to laser induced evaporation pressure. An optical vortex with a helical wavefront exhibits a donut-shaped spatial profile and an orbital angular momentum, and it has been leading to new fundamental sciences and advanced technologies. In recent years, we and our co-workers have proposed a new direct printing technology based on optical vortex, here referred as optical vortex laser induced forward transfer, in which a single optical vortex pulse twists the irradiated donor to eject and propel a pico-liter scale spinning microdroplet, thereby enabling well-aligned microdots with high spatial resolution on a receiver substrate. Going beyond conventional LIFT technologies, we here demonstrate the direct 2D print of well-aligned metallic microdots with a diameter of 15~45 µm, consisting of close-packed gold nanoparticles at high density, by the optical vortex laser induced forward transfer with the aid of a spin angular momentum associated with circular polarization. The electrical resistance of printed dot was measured to be ~10-7 Ωm, corresponding to 5-6 times higher than that of bulk gold. Optical vortex laser-induced forward transfer will pave the way towards next-generation printed electronics.