Additive Manufacturing of Metal Micro-ring and Tube by Laser-Assisted Electrophoretic Deposition with Laguerre–Gaussian Beam

We report a method for laser-assisted electrophoretic deposition using a Laguerre–Gaussian beam for maskless patterning of metal rings and tubes. These are structures of utmost importance, particularly in photonic devices. Metal nanoparticles, which are gathered in a colloidal solution by a laser trapping technique, are deposited on a substrate via electrophoresis. The deposition pattern is dependent on the focused spot shape during laser trapping. The intensity distribution of the Laguerre–Gaussian beam is ring-shaped. Rings with different inner diameters can be fabricated by varying the topological charge of the Laguerre–Gaussian beam. The equivalent inner diameters of the deposited rings with topological charges of 1, 3, and 5 were 0.30, 0.78, and 1.45 µm, respectively. The inner diameter of the deposited ring with a topological charge of 1 was smaller than the wavelength of the laser beam (532 nm). A tube was also fabricated with a topological charge of 3 by vertical displacement of the deposition cell. The deposition technology developed here using Laguerre–Gaussian beam will contribute to advancements in the fabrication of photonic and nano-fluidic devices. © 2021, International Society for Nanomanufacturing and Tianjin University and Springer Nature Singapore Pte Ltd.