US Patent 11819845 Magnetic conduits in microfluidics

A digital microfluidics system with electrodes attached to a substrate and covered by a hydrophobic surface and a control unit for manipulating liquid droplets by electrowetting, providing in close proximity to electrodes a magnetic conduit for directing a magnetic field of a backing magnet to the first hydrophobic surface, providing on the hydrophobic surface a liquid droplet that has magnetically responsive beads moving by electrowetting the liquid droplet with the magnetically responsive beads until a part of which is placed atop of the magnetic conduit, actuating the backing magnet of the magnetic conduit and attracting/concentrating magnetically responsive beads while actuating the backing magnet, moving by electrowetting the liquid droplet with decreased number of magnetically responsive beads away from the specific magnetic conduit. Also disclosed are a method for suspending magnetically responsive beads in liquid portions or droplets in digital microfluidics and a disposable cartridge to carry out the methods.