Surface-chemistry-driven actuation in nanoporous gold.
Although actuation in biological systems is exclusively powered by chemical energy, this concept has not been realized in man-made actuator technologies, as these rely on generating heat or electricity first. Here, we demonstrate that surface-chemistry-driven actuation can be realized in high-surface-area materials such as nanoporous gold. For example, we achieve reversible strain amplitudes of the order of a few tenths of a per cent by alternating exposure of nanoporous Au to ozone and carbon monoxide. The effect can be explained by adsorbate-induced changes of the surface stress, and can be used to convert chemical energy directly into a mechanical response, thus opening the door to surface-chemistry-driven actuator and sensor technologies.
Biener
J
J
Nanoscale Synthesis and Characterization Laboratory, Lawrence Livermore National Laboratory, Livermore, California 94550, USA. biener2@llnl.gov
Wittstock
A
A
Zepeda-Ruiz
L A
LA
Biener
M M
MM
Zielasek
V
V
Kramer
D
D
Viswanath
R N
RN
Weissmüller
J
J
Bäumer
M
M
Hamza
A V
AV