This paper demonstrated the plasma treatment of only 10 seconds on the parylene surface for changing its wetting behavior. CF4 and SF6 plasma gasses could increase the contact angle (of water) remarkably from 74 degree (lightly hydrophilic) to 123 degree (hydrophobic), whereas O2 plasma could reversely decrease the contact angle greatly from 75 degree to almost 0 degree (highly hydrophilic). The former can be applied to making the hydrophobic surface for driving liquid droplets, and the later can enhance the automatically filling flow caused by capillary suction. We apply the former to the micro-pillar array devices, and the max moving velocity of droplet is 23.06 mm/sec. Moreover, we also compared it with micro-pillar array which was modified by vapor of HMDS in this paper.
Proceedings of the 4th Asia Pacific Conference on Transducers and Micro-Nano Technologies (APCOT 2008)，4p.