Maskless Direct Printing of Radio Frequency Identification Antenna Based on Electrohydrodynamics Technology

This letter proposes an electrohydrodynamics-based printing system developed with high-precision on–off control, which has the merits of anticlog printing, maskless patterning, and precise control. Silver-colloid-based precursor can be conveniently focused into a single and continuous liquid jet and directly printed on glass or aluminum foil substrates just like a dip-pen. The liquid jet itself can be as thin as a couple of microns, and the minimum silver linewidth could reach 30 μm. With high-precision on–off control of the spraying, complex pictures, letters, as well as a specially designed radio frequency identification (RFID) tag antenna were printed using this system. The printed RFID tag antenna was characterized and analyzed, which meets the basic requirements of practical applications.