Femtosecond Laser Assisted 3D Etching Using Inorganic-Organic Etchant

Selective laser etching (SLE) is a technique that allows the fabrication of arbitrarily shaped glass micro-objects. In this work, we show how the capabilities of this technology can be improved in terms of selectivity and etch rate by applying an etchant solution based on a Potassium Hydroxide, water, and isopropanol mixture. By varying the concentrations of these constituents, the wetting properties, as well as the chemical reaction of fused silica etching, can be changed, allowing us to achieve etching rates in modified fused silica up to 820 mu m/h and selectivity up to similar to 3000. This is used to produce a high aspect ratio (up to 1:1000), straight and spiral microfluidic channels which are embedded inside a volume of glass. Complex 3D glass micro-structures are also demonstrated.

Automated summary

Selective laser etching (SLE) is improved by utilizing an etchant solution with specific constituents, which enhances selectivity and etch rate. Varying the concentrations of these constituents changes the wetting properties and chemical reaction of fused silica etching, allowing for high etch rates and selectivity. Complex microfluidic channels and 3D glass micro-structures are successfully fabricated using this method.