The visual appearance and shear strength of BSS. (a) Visual images of the 3D printed FL, and functional and baking surface of BSS (Scale bar = 2 mm), (b) Adhesion of FL of BSS on different substitute and pig skin under twisted and bent conditions, (c) Schematic diagram of slightly modified lap-shear test on pig skin, (d) The strain-stress curve of the overlapping lap-shear test, (e) Rheological characterizations of the hydrogels, showing the (e) storage modulus (G′), and (f) loss modulus (G″) against frequency.