An “all-diamond” inkjet realized in sacrificial layer technology

Recently, we have developed a universal fabrication technology for diamond surface microfluidics with high aspect ratio[1] [R. Müller, P. Schmid, A. Munding, R. Gronmaier, E. Kohn, Diamond Relat. Mater. 13 (2004) 780]. The key detail is a high aspect ratio sacrificial layer of copper, which is overgrown with diamond, followed by a dry-etch step to open a fluidic access to remove the sacrificial metal. In this approach, using the above mentioned sacrificial layer technology, an inkjet element is designed and fabricated where only diamond is in contact with the liquid. The result is a monolithic structure, i.e. no assembly of a nozzle-plate to the system involving alignment, gluing or bonding is necessary. The monolithic nature of the fabrication process also may allow to scale the system down to micron-size droplets.