  Some bi or multi-stable Mechanical meta-structures have been implemented as
mechanical memory devices which however are with limits such as complex
structural forms, low information storage capability and/or fragile structural
stability to maintain the stored information bits robustly under external
interferences. To address these issues, we refer to the structural intelligence
by constructing a simple 3D-printable multi-layered cylindrical kirigami module
with gradient structural parameters and propose a mechanical memory device that
can robustly store information bits exponentially larger than previous designs.
We demonstrate the promising enhancement of information storage capability of
our proposed mechanical memory device relies on two mechanisms 1 the
deformation sequences of the kirigami module enabled by the gradient structural
parameter, which brings the extra dimensional degree of freedom to break the
traditional mechanical memory unit with only planar form and merits information
bits with spatially combinatorical programmability, and 2 the combinatorics of
the deformation independences among the cylindrical kiriagmi unit arrays in the
constructed mechanical memory device. Particularly, we achieve both the
structural stabilities and the desired structural robustness in the mechanical
memory devices by additively introducing magnetic N-S poles in units, which can
protect the stored information from interferences like mechanical crushing,
impacting and or shaking.
