High-throughput preparation of microdroplet arrays by multi-channel electrohydrodynamic printing

Electrohydrodynamic (EHD) printing technology was well recognized for its high resolution and excellent material compatibility. Nevertheless, conventional single-nozzle EHD printing was constrained by low throughput. Multi-channel EHD printing was developed to overcome this limitation, but jet deflection and interruption were induced by electric-field coupling among nozzles, which degraded printing accuracy and microdroplet array uniformity. In this paper, a multi-physics coupling model was established to compare the electric field distributions of three typical nozzle array configurations. The simulation results revealed that a large electric field gradient could be generated by the single-row linear distribution. Based on this, a multi-channel spinneret with auxiliary electrodes was further designed. The spatial electric field distribution was optimized and the repulsive effects between jets were reduced through the introduction of solid nozzles. The influences of key process parameters, on jet stability and droplet deposition morphology were systematically investigated. Microdroplet arrays with average droplet diameters of 344–380 μm and printing frequencies of 198–324 Hz were successfully fabricated with the multi-channel spinneret with auxiliary electrodes. High-throughput preparation of microdroplet arrays was achieved through synergistic parameter optimization, and a feasible manufacturing solution for applications in flexible displays was thereby provided.