What You Need to Know
Gelatin‑based inks rely on thermal denaturation; heating to 30‑35 °C dissolves the polymer, yielding a viscosity of 1‑3 Pa·s at 25 °C that is shear‑thinning for extrusion and sets within 30‑60 s on a 5‑10 °C cooling plate. Alginate inks cross‑link instantly in a 2 % (w/v) CaCl₂ bath, forming a hydrogel in ≈10 s with a storage modulus >1 kPa. Both systems require a rheological yield stress of 10‑50 Pa and a loss tangent <0.5 to maintain over‑hangs and prevent collapse.
The Science
Primary Reaction
Thermal denaturation of gelatin and ionic cross‑linking of alginate with Ca²⁺