Page 375 - IJB-10-3

International Journal of Bioprinting Multi-physical field control inkjet bioprinting

discharge. The function of microdroplet velocity was and microdroplet acceleration, microdroplet acceleration
obtained by integrating this function, and the second and velocity, and diameter are all linear. Therefore, we
integration obtained the expression for the diameter. The employed a linear fitting method, based on experimental
experimental data were fitted using the integral form. data, to control microdroplet velocity and diameter using
voltage amplitude. A linear equation for controlling
3.1.2. Effect of voltage amplitude on microdroplet microdroplet velocity and diameter by voltage amplitude
diameter and velocity was derived by fitting the experimental data. According
Since bipolar waves drove piezoelectric ceramic, the to the specifications, the piezoelectric ceramic has a
vibration of the piezoelectric ceramic depended on the maximum working voltage of 144 V. Therefore, in order
voltage amplitude between the positive and negative to maintain its regular operation, we utilized a maximum
levels. For microdroplet formation, the voltage amplitude voltage amplitude of 288 V. Moreover, we used a high-
determined the deformation of the piezoelectric ceramic, speed camera to observe the diameter and velocity of a
which affected the formation of the pressure field and then microdroplet. The results are shown in Figure 4.
affected the diameter and velocity of the microdroplets. The
relationships between voltage amplitude and piezoelectric When the voltage amplitude was less than 132 V, the
ceramic shape variable, piezoelectric ceramic shape microdroplet could not be formed because the deformation
variable and printing head internal pressure, pressure of the piezoelectric ceramic was too slight. Microdroplet

Figure 4. Effect of the applied voltage amplitude on the microdroplet diameter (A) and velocity (B), n = 3. (C) A high-speed camera captured images
of a microdroplet at different voltage amplitudes. As the voltage amplitude increased, the diameter and velocity of the microdroplet also increased. By
measuring the distance the microdroplets traveled, it was observed that they moved faster as the voltage amplitude increased. Several voltage amplitudes
were displayed to showcase the varying velocity and diameter of the microdroplets.

Volume 10 Issue 3 (2024) 367 doi: 10.36922/ijb.2120