Microplasma stamps for selective surface modification: design and characterization

Microplasma stamps are based upon the principle of dielectric barrier discharges. They are applied to a new type of area-selective surface modification process at atmospheric pressure. This process integrates the surface treatment and lateral microstructuring within one process step. For this purpose the plasma is ignited in cavities which are formed temporarily by compressing the microplasma stamp and the substrate to be treated. The advantage of the microplasma stamp designs described in this work is the use of polydimethylsiloxane (PDMS) as a dielectric barrier. Because of its flexibility, PDMS enables a good adjustment to varying surfaces and with it ensures completely closed cavities. In this work the design of two different microplasma stamps is presented. Both designs are characterized considering the influence of the aspect ratio on the ignition and breakdown voltage as well as the ignition under varying conditions. All experiments have been carried out at atmospheric pressure with medium frequency excitation (33 kHz). Furthermore the experimental results are verified by simulations using an SIPDP and FEM model.