Rational assembly of 3D network materials and electronics through tensile buckling.

Bioinspired network designs are widely exploited in biointegrated electronics and tissue engineering because of their high stretchability, imperfection insensitivity, high permeability, and biomimetic J-shaped stress-strain responses. However, the fabrication of three-dimensionally (3D) architected electronic devices with ordered constructions of network microstructures remains challenging. Here, we introduce the tensile buckling of stacked multilayer precursors as a unique route to 3D network materials with regularly distributed 3D microstructures. A data-driven topology optimization framework enables efficient search of the optimal 2D precursor pattern that maximizes out-of-plane dimension of the resulting 3D network material. Computational and experimental results demonstrate rational assembly of optimal multilayer precursor structures into well-architected 3D network materials with an evident interlayer separation. The resulting 3D network materials offer anisotropic, tunable J-shaped stress-strain curves, which can be tailored to reproduce stress-strain responses of biological tissues. Demonstration of reconfigurable volumetric 3D display suggests rich application opportunities in biointegrated electronics and tissue scaffolds.