Long-lasting FR-4 surface hydrophilisation towards commercial PCB passive microfluidics

- Oxygen plasma treatment on FR-4 laminates.
- Effect of power and exposure time studied to achieve long-lasting hydrophilicity.
- Super-hydrophilic surface for 13 days demonstrated.
- Surface remains weakly hydrophilic between 13th and 26th day after the treatment.
- Hydrophilic behaviour is retained for 26 days in total.
- Passive filling of a PCB microfluidic network was enabled after O2 plasma treatment.