Fig. 3.

Various types of Smart Printing Materials that Respond to Physical Stimulation. A Schematic diagram of a moisture-responsive 4D bioprinting product [143]. (i) transparency capability demonstration, (ii) scanning electron microscope image, (iii) printed product affected by moisture beneath it, which in turn transforms the morphology. B Schematic diagram of temperature-responsive 4D bioprinting products [144]. C Schematic diagram of a 4D bioprinting product with electrical stimulation response [146]. D Schematic diagram of a magnetically responsive 4D bioprinting product for synergistic treatment of soft tissue injury system [147]. E Schematic diagram of a photoresponsive 4D bioprinting product [148]. F Schematic diagram of sound-responsive 4D bioprinting products. Numerical modeling demonstration of the displacement profile generated in GelMA prepolymer solution [149]. Reprinted with permission from Ref. [143, 144, 146–149]