# Microfluidic Femtosecond Laser-Induced Nucleation of Supersaturated Aqueous Sodium Chlorate Solutions

## TL;DR

This study combines microfluidic chips and femtosecond lasers to precisely control crystal formation in supersaturated sodium chlorate solutions.

## Contribution

A novel integration of femtosecond laser-induced crystallization with microfluidic technology for tunable crystal generation.

## Key findings

- A microfluidic device with a 3 mm channel enabled continuous laser pulse irradiation for controlled crystal growth.
- Crystal size and number were tunable using supersaturation, flow rate, laser energy, and pulse count.
- Nucleation was achieved at a low supersaturation threshold of σ = 0.002.

## Abstract

Femtosecond laser-induced crystallization has gained
significant attention due to its precise control over crystal formation
in recent years; however, challenges remain in improving the efficiency
and consistency of this process. Another emerging approach for crystallization
is the use of microfluidic systems, where strategies such as solvent
exchange, temperature modulation, and evaporation have been explored;
however, achieving consistent and localized nucleation remains an
active area of investigation. In this study, the probability of crystal
enhancement through the integration of femtosecond laser-induced crystallization
with microfluidic chip technology was investigated. A microfluidic
device with a channel width of 3 mm, capable of continuous femtosecond
laser pulse irradiation, was designed to control crystal number and
size growth under a controlled flow rate. Sequentially, tunable crystal
generation in the microfluidic chip was realized by irradiating the
channel with femtosecond laser pulse supersaturated sodium chlorate
(NaClO3) solution as low threshold as σ = 0.002.
The size and number of crystals could be tuned by the supersaturation
and flow rate of the sample solution, the laser pulse energy, and
the number of laser pulses.