A novel numerical controlled fluid microdispenser based on droplet impact

With advancements of fundamental research and industrial technologies, the application of fluid microdispensers has been continuously increasing. The range of liquid dosage and the capability of large-scale applications have become crucial performance indicators. This study developed a numerically controlled, non-contact fluid microdispenser based on the jetting phenomenon generated by the impact of microliter droplets on non-wetting surfaces. The device adopts modular designs and integrates a three-dimensional numerical control platform, enabling automated processes for microdroplet generation, separation, and collection. The microdroplet collection pathway was theoretically derived. Additionally, experiments and numerical simulations were conducted to study key dynamic processes, including droplet spreading, jet and microdroplet formations. This study reproduced the power-law relationship between microdroplet size and the normal Weber number, validated the functionality of the microdispenser, and analyzed the size deviation of microdroplets. Results show that the device can stably generate microdroplets under various normal Weber number conditions, with size deviations controlled within 15%. Furthermore, the device was used to achieve microdroplet array printing and microscale manufacturing, demonstrating its application potential in fields such as inkjet printing and material fabrication.