A mechanical system that assembles or deploys pre-stressed structures. The assembly or deployment process outputs and elastically deforms material to form flexural members having a sinusoidal shape and stored potential energy. The sinusoidal shaped members are oriented and deployed with support members as they take shape. Sinusoidal shaped members are formed from a series of contiguous flexures; each flexure's properties may be engineered using a simulation technique. Each flexure is formed from a region of a sinusoidal member's length that begins and ends at antinodes. During assembly or deployment support members are positioned at antinodes maintaining the flexures' shapes and the assembly's pre-stressed state. By controlling the forces applied to and position of each flexure formed during assembly, the distribution of potential energy within the assembly and its secondary shape can be engineered. Elastic potential energy may be harvested from the material forming the flexural members.