This parametric design video is about Cell Cycle: a generative product design application available online at http://n-e-r-v-o-u-s.com/cellCycle/ You can interact with a physics simulation of spring meshes to design your own cellular rings and bracelets for manufacture by 3d printing. The application was inspired by the intricate mineral skeletons of microscopic sea creatures called Radiolarians. The interactive software allows you to morph, twist, and subdivide each design transforming a simple mesh to a complex patterned structure. The bracelets are composed of a bilayer structure that juxtaposes two patterns on top of one another. The final designs are built up layer by layer in durable nylon plastic using Selective Laser Sintering, a kind of 3D printing. These forms would be impossible to create by traditional manufacturing methods. The process imparts the pieces with a coral-like texture.