Tong Zi Dan is a series of generatively designed vases made from dental gypsum.
The initial egg design gets randomly populated by a cloud of points which form the center for surfaces that trim the shape perpendicular to its curvature. A generative algorithm (Galapagos) is then used to create the area of all faces within a certain min/max range. Finally the faces are unrolled and laid onto a flat sheet to allow the production of the mold with a laser cutter.
In our experiment the gypsum gets enhanced with thermochromic pigments in one mixture and phosphorescent in another. It is then poured into the sealed molds and pivoted for a few minutes until the gypsum solidifies. The process is repeated for two more times to ensure a minimum wall thickness.
After the mixture has dried the vases can be removed from their enclosing molds. Since thermochromic pigments are heat sensitive, they change their color in response to a rise in temperature. The previously blue vase turns to white, the gypsum’s base color, when exposed to a fan heater.
Another interesting effect is generated by the phosphorescent pigments. During daylight the vase looks normal, but in darkness it starts to glow and create a different atmosphere.