Figure 1.

Schematic of present bioprinting techniques: (A) Inkjet bioprinters use a source of heat to create vapor in the print head. This vapor generates pressure within the nozzle that forces bioink from the tip. Piezoelectric print heads use pulses generated through ultrasound or piezoelectric pressure. (B) Extrusion printers use a mechanical dispensing system, requiring a screw, piston, or pneumatic pressure. (C) Laser bioprinting uses a laser pulse that strikes a point on a laser-absorbent surface; this surface generates a miniature burst of vapor that drives the biomaterial onto the substrate [6].