In an embodiment, a device includes: an electrode configured to change a contact angle of a liquid droplet above the electrode when a first voltage is applied to the electrode; a sensing film overlaying the electrode, wherein the electrode is configured for assessment of a state of the liquid droplet based on a second voltage sensed at the electrode; a reference electrode above the electrode, the reference electrode configured to provide a reference voltage; and a microfluidic channel between the electrode and the reference electrode, wherein the microfluidic channel is configured to manipulate the liquid droplet using the electrode.