Schematics of the DEP chip with the 3D printed electrodes. (a) Schematic of the DEP chip; the device consists of the PDMS top substrate and glass bottom substrate. The substrates are fabricated separately from each other before being assembled. On the glass substrate, the Au planar electrodes are patterned as a bottom electrode and Ag 3D electrodes are patterned locally on top of them. (b) The scale of the DEP chip and electrode: The scale of the DEP chip and Au, Ag electrodes.