Fig. 1.

Mobile microelectrode applied to cargo transport. a Schematic of the general concept of mobile microelectrode; localized gradients are induced around polarizable surface such that the spatial distribution of the field gradient in the system may be varied by manipulating the position of the Janus sphere; b Schematic illustrating concept of cargo transport; Janus particle picks up cargo, as it translates and transports it to a secondary location. c–g Microscope images showing accumulation, transport and release of 300 nm target by a 15 µm Janus particle carrier controlled by the frequency of the applied electric field.Video available in real time as Supplementary Video 1. c–e At 100 kHz, the 300 nm target accumulates at the metallic hemisphere under attractive pDEP. f, g At 2 MHz the target experiences a negative nDEP force and is ejected from the carrier surface. Scale bar illustrated in c is 10 µm