A novel method to enhance acoustic droplet bioprinting quality through analysis of parametric influence mechanisms
Three-dimensional bioprinting ushers a transformative change in tissue engineering, providing unparalleled opportunities for regenerative medicine by precisely fabricating intricate, biomimetic tissues. To achieve true organ-level in vitro tissue construction, various advanced bioprinting technologies have been developed. Among these, acoustic droplet bioprinting technology, with its excellent biocompatibility and multi-sample handling capabilities, offers an efficient liquid handling tool for tissue engineering printing. To meet the printing structure’s geometric precision requirements, meticulous control of printing parameters is essential. However, the determination of acoustic droplet printing parameters still depends heavily on empirical values, which often culminates in printing results that fall short of optimal standards. In this paper, a parameterized droplet dispensing method for multi-sample droplet excitation was established. This method introduces a unified scaling parameter based on the product of surface tension and viscosity, which integrates acoustic stress and fluid response into a single dimensionless quantity and enables precise adjustment of droplet velocity. The relative error between the initial velocity measured using this method and the preset velocity is less than 6.7%. Next, we analyzed the impact of droplet Overlap distance, Weber, and Ohnesorge numbers on the consistency of printed lines width. By employing optimized printing parameters, we achieved controllable printing of patterned hydrogel meshes suitable for cell culture. The results demonstrated that the lengths and widths of the nine sub-meshes exhibited high consistency. These advances move acoustic droplet bioprinting from an experience-driven process toward a more systematic, predictive, and reproducible parameter-optimization strategy.
