A Microscale 3D Printing Based on the Electric-Field-Driven Jet.

This study presents a novel microscale three-dimensional (3D) printing based on the electric-field-driven (EFD) jet. Differing from the traditional electrohydrodynamic jet printing with two counter electrodes, the EFD jet 3D printing forms electric field between the nozzle electrode and the top surface of the substrate or printed structure only using a single potential by the nozzle electrode. The numerical simulations and experimental studies were carried out to verify the capabilities and advantages of the proposed approach, which includes the suitability of substrates, the potentials of the conformal printing, and the large size 3D printing. Besides, considering the high-resolution and high-efficiency printing of various materials with different viscosities, two working modes, including the pulsed cone-jet mode and the continuous cone-jet mode, were proposed and investigated by the CCD camera. Finally, several typical printed structures were provided to demonstrate the feasibility of the proposed technology for microscale two-dimensional patterning and macro/micro-3D structure fabrication. As a conclusion, this breakthrough technique provides a high-efficiency and high-resolution 3D printing technique enabling direct-write, noncontact, and additive patterning at microscale for a variety of ink systems and melted polymer materials, especially for the multiscale and multimaterial additive manufacturing.