Goal: Research on droplet generation technology with a large volume range and high uniformity has great significance in biomedical engineering.
Methods: We explored the influence of both the liquid level height in the reservoir and the flow resistance distribution on the droplet volumes besides the nozzle size for the microfluidic impact printing (MIP) method. Finally, this droplet generation technology is applied to the preparation of lyophilized microbeads with high uniformity in volume.
Results: The coefficient of variation (CV) of the droplet volumes can be down to 0.55%. By adjusting the flow resistance distribution of the microchannels and the nozzle size, the droplet volume generated by the MIP system ranges from 0.4 nL to 610 nL.
Conclusion: On-demand droplet generation with high uniformity in the range of subnanoliter to submicroliter is achieved. Furthermore, this droplet generation technology is successfully applied to the preparation of highly uniform lyophilized microbeads.
Significance: This large volumetric range and highly uniform droplet generation technology has tremendous application potential in fields such as digital PCR detection, pharmaceutic preparation, and the construction of concentration arrays. Furthermore, it can also be used as a high-precision liquid distribution method for processing liquid in a submicroliter.