In-situ compression movies

In-situ compression movies with corresponding stress-strain curves were attached as Supplementary Movie S1-S6.

Supplementary Movie S1 showed fully recoverable deformation of 15 nm ceramic + 8 nm C-PDA nanolayered B-H-Lattice.

Supplementary Movie S2 showed the one-time deformation of a structure with 15 nm ceramic B-H-Lattice with in-situ stress and strains.

Supplementary Movie S3 showed the one-time deformation of a structure with 15 nm ceramic + 8 nm C-PDA nanolayered B-H-Lattice with in-situ stress and strains.

Supplementary Movie S4 showed the one-time deformation of a structure with 30 nm ceramic + 8 nm C-PDA nanolayered B-H-Lattice with in-situ stress and strains.

Supplementary Movie S5 showed the cycling deformation of a structure with 15 nm ceramic + 8 nm C-PDA nanolayered B-H-Lattice with in-situ stress and strains.

Supplementary Movie S6 showed the cycling deformation of a structure with 30 nm ceramic + 8 nm C-PDA nanolayered B-H-Lattice with in-situ stress and strains.

Figure S1. a) Composite hollow structures as prepared on a piece of glass slide; b) magnified view of a composite hollow structure; c) bottom corner of the composite hollow structure, milled by focus ion beam to expose the hollowness inside; d) schematic figure to show that pure ceramic hollow tubes flatten out during thermal removal of the inner resin, but composite tubes withstand thermal degradation of inner resin; e) a pure ceramic hollow structure as prepared with f) flattened struts; g) a composite hollow structure as prepared with h) tubular shaped struts. The thicknesses of alumina for structures in e) & g) are both 15 nm.

Figure S2. EDS mapping data of the lattices. a) The lattice after ALD deposition, with elemental maps showing successful deposition of Al2O3; b) the composite B-H-Lattice, with elemental maps showing both Al2O3 and C-PDA; c) the ceramic B-H-Lattice, with elemental maps showing only Al2O3 and no carbon.

Figure S3. XPS spectra for alumina/C-PDA composite film: a) Al 2p; b) O 1s. Spectra for C 1s and N 1s were included in Figure 2f&g. Calibration of the XPS peak positions was conducted by setting main C 1s peak to 284.8 eV.

Figure S4. AFM image of the edge of two different composite film on top of a glass slide. Red lines in the upper AFM images indicate the measured paths, of which the results are shown in the lower graphs. The composition of the films is: a) 15 nm alumina + 8 nm C-PDA; b) 30 nm alumina + 8 nm C-PDA.

Figure S5. AFM image of the dents generated by nanoindentation on a) 15 nm alumina; b) 15 nm alumina + 8 nm PDA. White lines in the AFM images indicates the measured paths, of which the results are shown in graphs on the right. Nanoindentation was performed respectively on each film on a soft substrate, the indentation depth is 1 μm.

Figure S6. Stress-strain curve and failure behavior for 30 nm Al2O3 + 8 nm C-PDA lattice. a) Stress-strain of such composite lattice during in-situ SEM compression; b) Overview of the lattice failing brittly; a through shear plane of failure can be observed; c) evolution of local failure at a node.

Figure S7. a) One-time compression of as-fabricated ceramic and composite hollow lattices; b) Incremental loading of two composite hollow lattices with different thickness ratios. c) Stress-strain curves of the 15-nm alumina lattice at the strain of 5% for 5 cycles; d) Stress-strain curves of the 15-nm alumina plus 8-nm C-PDA lattice at the strain of 5% for 20 cycles; e) Stress-strain curves of the 15-nm alumina plus 8-nm C-PDA lattice at the strain of 15% for 20 cycles;

Figure S8. a) Calculated stress-stress curves and corresponding moduli for different lattices. b) Comparison between the experimental and simulated moduli of different lattices.

Figure S9. a) A schematic showing the different rotational distribution (UR) on a vertical strut between beam bending and node bending. b) The path where the x-axis component of the UR is tracked. c) UR distribution for 3 types of lattices along the path at the compressive strain of 2.61%; d) UR distribution evolution for the 15 nm Al2O3 lattice; e) UR distribution evolution for the 15 nm Al2O3 +8 nm C-PDA lattice; f) UR distribution evolution for the 30 nm Al2O3 +8 nm C-PDA lattice;

Table S1 Peak UR representing beam bending and Plateau UR representing node bending value along the horizontal strut of different lattices at different strains.

15nm Al2O3 15nm Al2O3+

8nm C-PDA

30nm Al2O3+

8nm C-PDA

Strain/% Peak UR/Rad

Plateau UR/Rad

Peak UR/Rad

Plateau UR/Rad

Peak UR/Rad

Plateau UR/Rad

0.52 1.22e-2 <0 1.00e-2 9e-4 6.0e-3 2.6e-3

1.04 2.52e-2 <0 2.02e-2 1.9e-3 1.22e-2 5.3e-3

1.57 3.92e-2 <0 3.07e-2 3.3e-3 1.86e-2 8.1e-3

2.09 5.15e-2 5.8e-3 4.22e-2 5.3e-3 2.52e-2 1.10e-2

2.61 6.37e-2 1.24e-2 5.39e-2 8.3e-3 3.20e-2 1.42e-2