Research on immersion piezoelectric multi-nozzle coupled high-low frequency composite printing of viscous suspensions

To address issues such as multi-nozzle crosstalk, bubble interference, and poor compatibility between high and low-frequency jetting in the application of piezoelectric drop-on-demand (DoD) inkjet printing for viscous suspensions, this study proposes a piezoelectric multi-nozzle printing device (PMPD) which is high-low frequency composite. Immersing the piezoelectric vibrator directly in liquid reduces bubble-induced jetting failures, while the vibrator’s high-frequency vibration enables self-cleaning to remove nozzle deposits. Without a backpressure system, the PMPD achieves jetting via vibrator-generated pulsating pressure, supporting both low-frequency single-point and high-frequency continuous modes. Fluid-structure interaction (FSI) analysis of a single vibrator’s gas-liquid two-phase flow reveals the droplet formation mechanism: the vibrator’s periodic bending vibration induces pressure fluctuations through liquid film compression/expansion, promoting droplet formation and detachment. Dual-vibrator simulations confirm the baffle’s effectiveness in blocking pressure waves and reducing crosstalk. Experiments with 150 cSt glaze liquid show: an approximate linear positive correlation between voltage (180–300 Vp-p) and droplet diameter (0.33–0.43 mm); the largest/smallest diameter under square/sawtooth wave excitation; and optimal jetting with a 0.4 mm nozzle. the PMPD stably jets at 1.2 kHz (high droplet roundness/consistency). Multi-nozzle synchronous jetting and patterned printing verify its large-scale integration capability and high-viscosity fluid compatibility, offering a new solution for efficient viscous suspension printing.