An Effective Capillary Valve based on Micro-hole Array for Microfluidic Systems

Yang Xie, Hui You, Zhiyuan Gao, Zhe Huang, Mingpeng Yang
2018 Analytical Sciences  
With the development of microfluidic systems for portable devices where the capillary force as the driving force drove the liquid in microchannel. An effective capillary microvalve based on a micro-hole array is proposed in this paper for the purpose of good performance, programmable control, and easy-to-fabricate. The Wenzel model was used to slow down the velocity of fluid flow. The microvalve was made by hot-embossing and hot-bonding process. The valve function was assessed by liquid flowing
more » ... experiments. The results showed that the valve employs an abruptly changing contact angle to slow down the fluid flow. The controlling time is approximately 177 -213 seconds. The best control effect was obtained when the contact angle equaled to 90 °. The effect of the roughness of the microvalve was also evaluated. Therefore, this work has a great potential and broad prospect for both research and application in microfluidic systems, such as the portable devices in the medical testing field. geometry of the flow path to delay a moving liquid filling front in a wettable micro-channel, however, this method shown poor control performance in fluid flow 23 . Xin Du et al. reported a passive through hole microvalve for capillary flow control. The gating condition on regulating flow was derived based on the contact line theory. The valve was limited due to the control performance and the fabrication 24 . Thus, it is significant to find an alternative method for Advance Publication by J-STAGE
doi:10.2116/analsci.18p257 pmid:30101831 fatcat:hzq4aucwr5gmbebjvsngnstdza