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International Journal of Bioprinting Multi-physical field control inkjet bioprinting

Figure 1. Principle of microdroplet formation based on multi-physical field control piezoelectric inkjet bioprinting (MFCPIB). (A) Actuation waveform.
(B) Schematic representation of the MFCPIB method mechanism. (C) Schematic of the vascular model and gelatin methacryloyl (GelMA) microdroplets
containing smooth muscle cells (SMCs). (D) Technical route of MFCPIB.

effect, the piezoceramic stretched along the direction of The assembly of microdroplets depended on the
the tube radius when the strong electrical level caused control of the temperature field, as shown in Figure 1B, and
the inner diameter of the tubular piezoelectric ceramic microdroplets formed with a certain velocity and diameter
to shrink and the pressure field strength to increase. This under the effect of the pressure field and entered the
process squeezed the bioink out of the nozzle. The inner temperature field. According to the velocity and diameter
diameter of the tubular piezoelectric ceramic expanded of a microdroplet, its physical properties were controlled
at a low electrical level, increasing the tube volume and by adjusting the temperature of the thermosensitive
decreasing the strength of the pressure field. The ink materials. As a result, the high-temperature microdroplets
contracted at the nozzle orifice, and the liquid column was passed through the temperature field, cooled, solidified,
pulled by microdroplets formed by GelMA and SMCs. The and assembled; then, layer by layer, the gel formed vessel-
piezoelectric effect and fluid-structure coupling module like structures, as shown in Figure 1C.
of COMSOL (version 5.6, COMSOL Inc., Sweden) were
used for simulation and analysis, and the law of pressure The technical route of MFCPIB is shown in Figure
field controlling microdroplet diameter and velocity was 1D. The voltage amplitude and pulse width were used to
obtained. We controlled the formation, diameter, and adjust the pressure field. The pressure field controlled the
velocity of microdroplets as required. diameter and velocity of the microdroplets. The speed

Volume 10 Issue 3 (2024) 363 doi: 10.36922/ijb.2120