Water-assisted femtosecond laser ablation for fabricating three-dimensional microfluidic chips

• 3D microfluidic chips were etched in the silica glass by water-assisted femtosecond laser.
• We present a simple and practical method to produce 3D multilayer microfluidic chips in silica glass.
• We introduce a convenient cleaning method for diluting and ejecting the ablated debris from microchannel.
• Experimental results show that the microchannel is uniform and the complexity of the microfluidic chip is under control.

When the femtosecond laser focused in the water, the breakdown will be induced. The generated high-speed jet and shock wave can be used to etch silica glass for fabricating three-dimensional (3D) microfluidic chips. We present a simple and practical method to produce 3D multilayer microfluidic chips in silica glass. This method offers high design flexibility and fabricating feasibility. We also introduce a convenient cleaning method for diluting and ejecting the ablated debris from microchannel. Therefore, the femtosecond laser induced high-speed jet and shock wave can be used to fabricate complex microfluidic chips in silica glass. Experimental results show that the diameter of microchannel is uniform and the complexity of the microfluidic chip is under control. As a proof of principle, we demonstrate the feasibility of the fabricating process by using the water-assisted femtosecond laser ablation.