Fig. 9

Needle-free jet injection visualization in ex vivo porcine skin tissue under optimum (a) fluorescence imaging and (b) absorbance imaging conditions. Color bar signifies the relative presence of fluid based on pixel intensity. For fluorescence imaging mode, pixel intensity in the injection front was higher than surrounding and it was lower for absorbance imaging mode. The variation was normalized into a uniform scale to show the relative presence of injected fluid inside the tissue. c The penetration profile of the injected fluid in 15% polyacrylamide hydrogel