Cartridge and electrowetting sample processing system with delivery zone

A method for operating a cartridge in an electrowetting sample processing system, the cartridge comprising, a liquid input port, an internal gap with at least one hydrophobic surface, at least two processing zones for processing samples located in the at least two processing zones and a delivery zone for delivering multiple droplets from the liquid input port to the at least two processing zones, wherein the method comprises:

• introducing an input liquid into the internal gap of the cartridge, the input liquid providing for at least one droplet, directly or via a liquid separation process within the internal gap;
• providing a repeating pattern of interacting electrowetting force for simultaneously and only unidirectionally transporting multiple droplets within the delivery zone;
• delivering the at least one droplet from the liquid input port to one of the at least two processing zones.