Ultrahigh-frequency electrohydrodynamic jetting with adjustable modes for rapid printing of high-resolution patterns

The electrohydrodynamic (EHD) inkjet printing is rooted in the creep effect exhibited by fluid interfaces subjected to high-intensity electric fields. It utilizes the micro-jetting from the tip of the Taylor cone to print intricate patterns with sub-micron feature sizes. However, due to the limitations inherent in the jetting mechanism, the highest printing frequencies for conventional EHD are limited to several hundred Hertz. Here, we discover a novel phenomenon where the vibration of meniscus in an electric field can induce EHD jetting within microseconds, or even sub-microseconds. Based on this phenomenon, we propose a new method for achieving megahertz level EHD jetting based on meniscus vibrations (MVEHD). This paper systematically elucidates the fundamental mechanisms of the forced meniscus vibration, cone sharpening, and the jetting formation through a combination of experimental research and numerical simulation. Additionally, adjustable continues inkjet (CIJ) and drop on demand (DOD) inkjet printing modes were developed, demonstrating the potential of dual-mode technology in the development of automotive transparent glass heaters (TGHs) and Micro-LED displays. This method effectively elevates the efficiency of traditional EHD by 2 to 4 orders of magnitude, thereby laying a theoretical and technical foundation for the industrial application of high-throughput EHD technology.