A novel hybrid maize variety designated 33F12 and seed, plants and plant parts thereof, produced by crossing Pioneer Hi-Bred International, Inc. The digital microfluidics system includes a first substrate with an array of electrodes and a central control unit for controlling the selection and for providing a number of the electrodes with voltage for manipulating liquid portions or droplets by electrowetting. The clock tree deskew circuit reduces the clock tree skew in repeated intervals over a period of time.