Layer-based laminating manufacturing methods (e.g., Smart Composite Microstructures, SCM) fabricate a foldable 2D structure and then form the final 3D structure and mechanism through folding with minimal assembly. This approach is well suited for small-scale robots because built-in flexure joints can provide motion without conventional part assemblies such as bearings and shafts.

For spring elements, however, these methods typically rely on 2D patterned composite beams springs.

Such springs offer limited flexibility in independently designing target stiffness and neutral position: unlike structural parts, a 2D-patterned spring cannot simply be folded into a 3D rest configuration, and its neutral position remains inherently flat. As a result, springs with non-flat neutral positions are often added as separate components after fabrication, which increases manufacturing difficulty—especially at small scales.

To overcome this limitation, I proposed a sheet-metal–embedded laminated fabrication approach in which stamping is used to tune both stiffness and neutral position after lamination. By embedding patterned sheet metal within the laminate and applying controlled plastic deformation through stamping, the method allows for the integration of the more complicated rotational and axial spring without additional assembly. I analyzed the stamped sheet-metal spring using a PRBM-based analytical model, established a practical design method supported by experiments, and demonstrated the approach by fabricating a small-scale jumping robot.