Laser-driven jetting of nanoscale non-conducting liquid droplets via hollow optical fiber

TL;DR

This paper demonstrates a novel laser-driven method using hollow optical fibers to atomize non-conducting liquids into nanoscale droplets, enabling precise, electrode-free liquid jetting with potential biomedical applications.

Contribution

It introduces a new hollow optical fiber technique for laser-driven atomization of non-conducting liquids, eliminating the need for electrodes or air pressure.

Findings

Successfully produced nanoscale droplets from non-conducting liquids.

Controlled droplet size distribution by adjusting laser power and distance.

Potential for in-situ biomedical liquid delivery in microscopic environments.

Abstract

Along a single strand of micro-capillary optical waveguide, we achieved an efficient transfer of the light momentum onto the liquid contained there within, successfully atomizing it into nanoscale droplets. A hollow optical fiber (HOF), with a ring core and central air hole, was used to optically drive jetting of non-conducting transparent liquid of sub-pico liter volume, out of a surface-treated facet orifice, producing droplets ranging from nano to micrometer scale. These droplets were carried over the propagating light field forming a spherical cone, which were then deposited on a silica substrate in a Gaussian spatial distribution. The deposited patterns and sizes of individual droplets were characterized as a function of the laser power, irradiation time, and distance between the HOF and a substrate. This HOF based laser driven atomization technique obviates imperative electrode or aerial pressure requirements in prior methods, opening a new pathway to drastically scale down the form-factor of liquid jetting devices, and has a high potential to in-situ atomization and delivery of bio-medical non-conducting liquids in a microscopic environment, which was not possible in prior arts.