this document describes an advanced laboratory platform rocker . an electronic circuit controls the rotation of the shaft of a motor . the shaft is coupled to the platform , such that the angular position of the platform is controllable , as a function of time , enabling non - periodic and non - steady motion . the rotation of the platform can be used to perform other functions , such as initiating the dispensing of liquid into a tray on the platform , and dispersing of liquid from a tray on the platform .