Mechanical structure for shock absorption and vibration reduction

A single layer structure comprising:

• a plurality of unit cells arranged in a single layer, each unit cell comprising:
• a first bowling pin structure interlocked with a second bowling pin structure arranged in an opposite orientation to the first bowling pin structure,
• the first bowling pin structure having a first sidewall, a first wide end, and an opposing first narrow or equal size end, the second bowling pin structure having a second sidewall, a second wide end, and an opposing second narrow or equal size end,
• wherein each of the bowling pin structure has a center axis along a longitudinal or vertical axis of the single layer structure, the first and second sidewalls configured to have a 3D “S” shape along the longitudinal or vertical axis such that each of the first wide end and the second wide end has a convex shape and each of the first narrow or equal size end and the second narrow or equal size end has a concave shape.