Study of living cell distribution during inkjet printing of bioink

Inkjet printing as a viable technology has been widely adapted for various biomedical applications, such as 3D biofabrication which utilizes the droplets generated from inkjet printing of bioink to build 3D viable structures. One of the key challenges is cell distribution which is cell number embedded per droplet/microsphere. It significantly affects the post-printing cell viability and proliferation. This paper focuses on the effect of excitation voltage on the living cell distribution during drop-ondemand inkjet printing of bioink containing living cells. The cell distribution results are compared under two different excitation voltages of 40V and 50V. The normal distribution is used to fit the experimental results. It is found that 1) at both 40V and 50V, the mean cell number of the experimental results is always smaller than the theoretical value due to cell motion inside the nozzle; and 2) the mean cell number errors are 3% at 40V and 18% at 50V, which is due to different ligament flow near the nozzle orifice. The resulting knowledge benefits efficient and effective fabrication of 3D cellular constructs with uniform cell distribution.