A biological sample processing system (1) includes a liquid droplet manipulation instrument (20) with an electrode array (21) for inducing a movement of a liquid droplet (19) by electrowetting; a substrate (22); and a control unit (23). An electrode selector (34) of the control unit (23) is configured to individually select and provide each electrode (35) of the electrode array (21) with a voltage. The control unit (23) includes a central processing unit (36) for individually selecting at least one electrode (35) and for providing the selected electrode(s) (35) with an individual voltage pulse. The biological sample processing system (1) also includes a cartridge (40) with a container (2).