Simulation and basic experiment of picoliter droplet micro-dispensing based on piezoelectric drive

Microdroplet dispensing has numerous applications in biotechnology, microelectronic packaging and microassembly. The rapid developments of these fields tend to demand smaller and smaller microdroplets. In order to achieve single picoliter-volume droplets, a piezoelectric micro-dispensing system is developed in this paper. The factors affecting the droplet volume is first investigated theoretically. Then the coupled multi-physics micro-dispensing model has been established. Based on this model, various parameters such as driving voltage, the nozzle diameter and glue viscosity that influence the microdispensing performance are analyzed. The process of microdroplet formation is also simulated accordingly. The simulation results show the minimum volume that of a nozzle with a 20μm inner diameter can distribute is about 20pL. Basic microdispensing experiments are executed, verification of micro-dispensing is ultimately performed in the built system.