1
Supplementary
Information
for
Lightweight, flaw
-
tolerant and ultrastrong nanoarchitected carbon
Xuan Zhang, Andrey Vyatskikh, Huajian Ga
o, Julia R. Greer, Xiaoyan Li
Corresponding authors:
Huajian Gao, Julia R. Greer,
and
Xiaoyan Li
Email:
Huajian_Gao@brown.edu
(H.G.),
jrgreer@caltech.edu
(J.G.)
, and
xiaoyanlithu@tsinghua.edu.cn
(X.L.)
This PDF file
includes:
Fig
s.
S1
to
S7
Table
S1
Captions for
m
ovies S1 to S2
Other
supplementary materials
for this manuscript
include
the following
:
Movie
s
S1 to S2
www.pnas.org/cgi/doi/10.1073/pnas.1817309116
2
Fig. S1.
SEM images of typical octet
-
and iso
-
truss nanolattices before and after compression. (
A
,
B
) SEM images of an octet
-
truss nanolattice with
d
=382 nm. (
C
,
D
) SEM images of the iso
-
truss
nanolattice with
d
1
=538 nm and
d
2
=612 nm. The
images in (
B
) and (
D
) indicate brittle failure of
nanolattices.
3
Fig. S2
.
In
-
situ compression tests on polymer nanolattices. (
A
) Compressive stress
-
strain curve of
octet
-
truss nanolattice with
d
=1.12
m. (
B
-
D
) SEM snapshots of deformed octet
-
truss
nanolattice
under different compressive strains. (
E
) Compressive stress
-
strain curve of iso
-
truss nanolattice
with
d
1
=1.30
m and
d
2
=1.49
m. (
F
-
H
) SEM snapshots of deformed iso
-
truss nanolattice under
different compressive strains. The circled regions in
(
C
) and (
G
) indicate the buckling of struts
during compression.
4
Fig. S
3
.
Young
’
s modulus and compressive strength versus density of pyrolytic carbon
nanolattices.
(
A
,
B
) Young’s modulus and strength versus relative density of octet
-
and iso
-
truss
pyrolytic carbon nanolattices
on log
-
log scale. Scaling power law slopes are indicated for each
architecture.
Error bars
represent
the
standard
deviation
s from the
average
over some data of
samples with comparable densities.
5
Fig. S
4
.
Comparison between
finite element modelling and experimental results. (
A
,
B
) Modulus
versus relative density and strength versus relative density from finite
-
element modelling and
experiment. While the modelling results based on solid elements are in good agreement with
tho
se from experimental measurements, those based on beam elements exhibit similar trend but
larger deviations from experiments at higher relative densities.
6
Fig. S
5
.
Relative reduction in strength of nanolattices as a function of the extent of initial
de
flection. (
A
,
B
) Results from finite element modelling based on beam and solid elements.
7
Fig. S
6
.
Comparisons of deformation snapshots in octet
-
truss nanolattice with relative density of
37.5% from finite element modelling and in
-
situ experiments. (
A
,
B
,
C
) SEM images from in
-
situ
testing at different strains. (
D
,
E
,
F
) Snapshots from finite element modelling with solid elements
at different strains.
8
Fig. S
7
.
Comparison of deformation snapshots in an iso
-
truss nanolattice with relative density of
39.4% from finite element modelling and in
-
situ experiments. (
A
,
B
,
C
) SEM images from in
-
situ
testing at different strains. (
D
,
E
,
F
) Snapshots from finite element modelling with solid elements
at different strains.
9
Table S1.
Mechanical properties of p
olymer microlattices under compression
Unit cell
geometry
Relative density
(%)
Young
’
s modulus
E
(
MPa
)
Strength
y
(MPa)
Iso
9.21
112
4.47
12.38
172
7.20
Octet
11.85
89
5.52
16.22
109
7.49
10
Movie S1
.
In
-
situ uniaxial
compression of octet
-
truss nanolattice with relative density of 37.5%.
The nanolattice first underwent the elastic deformation, and then failed due to the brittle fracture.
The fracture strength is up to about 300 MPa.
Movie S2
.
In
-
situ uniaxial compression of iso
-
truss nanolattice with relative density of
39.4
%.
The nanolattice first underwent the elastic deformation, and then failed due to the brittle fracture.
The fracture strength is as high as 400 MPa.