In order to make droplet-based digital microfluidics really 'digital' and compatible with standard integrated chips (ICs), a novel low-voltage droplet manipulation method named 'liquid dielectrophoresis on electret (L-DEPOE)' is proposed for dielectric liquids, which initializes the possibility of digital microfluidics for IC control and broad consumer electronic applications. By employing electret as a virtual voltage source embedded into microfluidics for the first time, a dielectric droplet between two electrodes can be transported by liquid dielectrophoresis (L-DEP) force when switching an external capacitor between electrodes using a manual switch or low-voltage-driven relays. A circuit model and force analysis for L-DEPOE are established to clarify its working principle and quantitatively depict the droplet motion. Nanoliter dielectric droplets have been transported reversibly between the two electrodes with a manual switch or five DCV-driven relays in microfabricated proof-of-concept prototypes. The surface voltage stability of electret in liquid is examined with different polymer materials and coatings. Furthermore, the droplet motion traces in a L-DEPOE device are compared with numerical simulation results, indicating the important role of contact angle hysteresis for nanoliter droplets.