Manipulation of sample droplets with an electrode system

A method for processing a set of sample droplets, the method including:

• transmitting a sample droplet of a set of sample droplets from a sample reservoir into a region between a first layer and a second layer of a magnetic separation unit, wherein the first layer is coupled to an electrode array network with a non-conductive material layer, the electrode array network being configured to modulate voltage states at each electrode of the electrode array network to provide a pattern of controlled electric fields for manipulation of the set of sample droplets, the first layer being composed of a flexible hydrophobic material and the second layer being a rigid layer opposite the first layer and displaced from the first layer;
• upon activation of a first subset of electrodes of the electrode array network, generating a first stage droplet upon combining the sample droplet with a binding droplet including a set of magnetic particles for binding with targets of the sample droplet;
• upon activation of a second subset of electrodes of the electrode array network, transmitting the first stage droplet to a magnetic region between the first layer and the second layer of the magnetic separation unit;
• retaining a target portion of the first stage droplet within the magnetic region while transmitting a non-target portion of the first stage droplet to an outlet of the magnetic separation unit, upon activation of a third subset of electrodes of the electrode array network;
• upon activation of a fourth subset of electrodes of the electrode array network, generating a second stage droplet upon combining the target portion with an elution droplet for elution of targets from the set of magnetic particles;
• and
• upon activation of a fifth subset of electrodes of the electrode array network, transmitting the target portion of the second stage droplet toward an outlet of the magnetic separation unit.