FABRICATION OF 3D DIAMOND MEMBRANES FOR MICROFLUIDIC SYSTEMS

Perfusion of cell medium, especially in microfluidic devices, can provide in-vivo-like conditions for cell cultures. The most recent demand on such systems is to include electronically active artificial cell support for in-situ monitoring. Diamond thin films exhibit advantageous combination of physical, mechanical, chemical, biocompatible and electronic properties for this purpose. In this work we explore two strategies for fabrication of self-standing three-dimensional monocrystalline diamond membrane for implementation in microfluidic invivo like experiments: i) nucleation and chemical vapour deposition (CVD) growth of diamond on porous 3D carbon foam (with 80 pores per inch) and ii) selective diamond growth predefined by photolithographic processing using copper grid mask. The morphology and material quality of the fabricated membranes are characterized by scanning electron microscopy and Raman spectroscopy. We discuss influence of surface pre-treatment (plasma vs. wet chemistry), seeding procedure (water vs. methanol based diamond nanoparticle suspension), and diamond growth regimes (focused vs. linear antenna microwave plasma CVD system). Moreover, we identify crucial factors for fabrication of such membranes.