of 2
1
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0
10
20
30
40
50
60
0
100
200
300
400
500
Storage Modulus, MPa
Loss Modulus, MPa
Tan delta
Frequency, Hz
Post-densification,
ɛ
0.65
Pre-densification,
ɛ
0.65
Post-densification,
ɛ
0.65
Pre-densification,
ɛ
0.65
0 102030405060
10 nm/s
Post-densification,
ɛ
0.65
Pre-densification,
ɛ
0.65
Figure S1 (Supporting online material). The viscoelas
tic indentation response of the VACNT micro-pillars
loaded at a rate of 10 nm/s, in terms of the measured values (average ±standard deviation) of their (a)
storage modulus, (b) loss modulus and (c) tan
δ
values, as a function of frequency.
(a)
(b)
(c)
2
Loss coefficient,
η
Cycle number
Loss coefficient,
η
Cycle number
Cycle number
Cycle number
1000 nm/s
100 nm/s
10 nm/s
1000 nm/s
100 nm/s
10 nm/s
Area
Δ
U
Area
U
1
2
U
U
i
i
i
U
U
2
12345
12345
12345
12345
0
0.05
0.1
0.15
0
0.
05
0.1
0.15
Area
Δ
U
Area
U
Pre-densification,
ɛ
0.65
Post-densification,
ɛ
0.65
Pre-densification,
ɛ
0.65
Post-densification,
ɛ
0.65
1000 nm/s
100 nm/s
10 nm/s
(a)
(b)
Figure S2 (Supporting online material). (a) The loss c
oefficient
values calculated using Eq. (2) and (b) using
Eq. (3) as a function of load-unload cycles showing better energy dissipation at higher rates.