New Ion-selective Sensing Platform: Additively Manufactured Flexible Digital Microfluidic System

We developed an additively manufactured EWODbased digital microfluidic (DMF) platform for the ion-selective sensing technology. The flexible DMF electrodes are fabricated through direct-writing based 3D printing to unfold their dimensional limitation. When solution droplet is moving, the electrode's capacitance change is monitored so that the position and speed of the droplet are quantitatively detected. The ion-selective sensing function is demonstrated with blending of multiple ions with DMF through a thin layer of PVC based ion-selective membrane coated on the sensing station. Reliable ion selectivity is demonstrated through a comparison between primary NH ⁴⁺ and interference K+ ions.