Design, manufacturing and evaluationof high pressure microfluidic chips with integrated corona discharge electrodes

• Main Author: Stocklassa, Jesper
• Format: Others
• Language: English
• Published: Uppsala universitet, Mikrosystemteknik 2016
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-303305

In this thesis possibilities of generating corona discharges in supercritical carbon dioxide inside a micro fabricated glass chip are investigated. Managing to do so would enable high throughput research of new chemical reaction fields and analytical spectrometry in the supercritical phase with low equipment costs compared to available technology used today. The aims of the thesis were to design, manufacture and test a chip of this kind that can withstand pressures of 125 bar and be used to study corona discharges by investigating how pressure, electrode geometry and interelectrode distance can affect operating voltages and if light emission from corona discharges could be captured from outside the chip. Chips were successfully manufactured using standard cleanroom techniques like lithography, wet etching, sputter deposition and fusion bonding. Testing showed that one electrode design was superior to the others in terms of operation stability, corona current and light emission and that interelectrode distance of 2 um and 3 um seem preferable compared to larger distances. Electrode erosion during operation proved to be a big problem for electrode lifetime and measurement repeatability and must therefore be improved for further development.