Pulsed Bessel beam-induced microchannels on a diamond surface for versatile microfluidic and sensing applications

We present a laser machining method based on the use of pulsed Bessel beams to create, by single pass transverse writing, three-dimensional trench-like microstructures on a synthetic monocrystalline diamond substrate. By tuning the laser pulse energy and the writing speed, it is possible to control the features of the surface trenches obtained and to optimize the resulting high aspect-ratio and low roughness microstructures. This work confirms the potentialities of quasi-stationary beams in ultra-fast laser inscription technology. In particular the presented results show the possibility to fabricate deep and precise microfluidic channels on biocompatible diamond substrates, offering a great potential for biomedical sensing applications.