Controlling two-phase flow in microfluidic systems using electrowetting

Electrowetting (EW)-based digital microfluidic systems (DMF) and droplet-based two-phase flow microfluidic systems (TPF) with closed channels are the most widely used microfluidic platforms. In general, these two approaches have been considered independently. However, integrating the two technologies into one allows to combine the advantages of both worlds: (i) high throughput (from TPF) and (ii) precise control over each individual drop (from EW). Thus the aim of this thesis was to investigate the combination of EW technology and the droplet-based TPF platform. Hence we designed and developed several of such hybrid microfluidic chips, using different approaches and microfabrication technologies. We demonstrated the new functionalities of the developed devices and explored the physics ingredients based on our observations.