Fig. 4: Multifunctionalities of mineral-polymer composites.

a–c Structure-programmability: a Schematic to show a sandwich sample with polymer lattice in the center and mineralized regions at two ends. b, c Fabricated sandwich sample before and after compression. d–g Process-reversibility: d Fabricated mineralized composite sample. e The sample submerged in a hydrochloric acid solution (1 mol/L). f Demineralized sample after removing the CaCO₃ mineral phase. g Re-mineralized composite sample with the proposed electrochemical manufacturing process. h–k Fire-resistance: h, i The mineralized composite sample after being put on fire for 5 min and 30 min. j The mineralized composite sample after being fire-burned for 30 min. k Force-displacement curves of unnotched two-section compact shear tests for the mineralized composite before and after being fire-burned for 30 min. The inset shows the schematic for the unnotched two-section compact shear test. l, m Crack-repairability: l Mineralized composite sample at different states of the electrochemical mineralization enabled crack repairing. m Force-displacement curves of three-point bending tests for the mineralized composite at the original state and after being repaired. The inset shows the schematic for the three-point bending test.