Femtosecond Laser Assisted 3D Etching Using Inorganic-Organic Etchant

Area of Science:

• Materials Science
• Microfabrication
• Chemical Engineering

Background:

• Selective laser etching (SLE) enables the creation of intricate glass micro-objects.
• Existing SLE techniques face limitations in etch rate and selectivity.

Purpose of the Study:

• To enhance the selectivity and etch rate of SLE for fused silica.
• To develop an optimized etchant solution for improved glass microfabrication.
• To demonstrate the fabrication of high aspect ratio microfluidic channels and complex 3D structures.

Main Methods:

• Utilized a novel etchant solution composed of Potassium Hydroxide, water, and isopropanol.
• Varied the concentrations of etchant constituents to modify wetting properties and chemical reaction kinetics.
• Investigated the etching process of modified fused silica.

Main Results:

• Achieved significantly improved etch rates up to 820 μm/h.
• Reached high selectivity values up to approximately 3000.
• Successfully fabricated straight and spiral microfluidic channels with aspect ratios up to 1:1000.
• Demonstrated the fabrication of complex 3D glass micro-structures.

Conclusions:

• The optimized etchant solution substantially improves SLE performance for fused silica.
• This advancement enables precise fabrication of high aspect ratio and complex 3D glass microstructures.
• The developed method offers a versatile platform for microfluidics and other micro-device applications.