Noncontact electric field-driven jet 3D printing for fabrication of microscale patterns on nonflat substrate

Conformal 3D printing can significantly enhance the design flexibility and functional integration of device structures, and is widely applied in fields such as aerospace and biomedical engineering. However, high-resolution and consistent printing on nonflat substrates presents significant challenges. This paper proposes a noncontact electric field-driven (NEFD) jet micro 3D printing for fabricating high-resolution microscale structures on nonflat substrates. The electric field stability is improved by optimizing the structure of the extraction electrode and maintaining consistent printing height. The jet is perpendicular to the substrate surface to ensure high consistency of the print linewidth. The experiments were conducted on two typical nonflat substrates. The influence of the substrate structure with a large height difference on the electric field intensity and linewidth were investigated. The results showed that the variation rate of the linewidth printed on a substrate with a maximum height difference of 30 mm was less than 11%. In large-area substrate printing, a rangefinder was used to compensate for the Z -axis height in real time. The linewidth variation was less than 1.5% for 10 μm and 20 μm silver wires printed on a 250 × 250 mm large-area glass substrate. In conclusion, the NEFD jet micro 3D printing has broad applications on nonplanar substrates.