Microfluidic device and a method of loading fluid therein

A method of extracting fluid from an AM-EWOD microfluidic device, the microfluidic device comprising:

• upper and lower spaced apart substrates defining a fluid chamber therebetween;
• a plurality of independently addressable array element electrodes, each of the plurality of independently addressable array element electrodes defining a respective array element, and each of the respective array elements defining a respective region of the fluid chamber;
• and
• an aperture for receiving fluid into the fluid chamber;
• the method comprising:
• extracting working fluid from a first region of the microfluidic device, the first region spaced from the aperture, by;
• actuating one or more array elements of the AM-EWOD device to move working fluid from the first region to an unloading region adjacent the aperture and external to the fluid chamber;
• and
• removing the working fluid from the unloading region into the fluid chamber via the aperture.

An active matrix electrowetting on dielectric (AM-EWOD) microfluidic device comprising:

• upper and lower spaced apart substrates defining a fluid chamber therebetween;
• and
• an aperture for introducing fluid into the fluid chamber;
• a plurality of independently addressable array element electrodes, each of the plurality of independently addressable array element electrodes defining a respective array element, and each of the respective array elements corresponding to a respective region of the fluid chamber;
• and
• control means for addressing the array elements, the control means configured to:
• determine, by controlling the EWOD array elements to operate in a sensing mode, that a working fluid has been introduced into a first region of the fluid chamber;
• and
• provide an output to a user to indicate that the working fluid is present in the first region;
• wherein the control means is configured to actuate a first group of the array elements of the microfluidic device, the first group of the array elements corresponding to the first region of the fluid chamber to move working fluid introduced via the aperture to the first region of the fluid chamber.