Achieving Superior Two-Way Actuation by the Stress-Coupling of Nanoribbons and Nanocrystalline Shape Memory Alloy.
Inspired by the driving principle of traditional bias-type two-way actuators, we developed a novel two-way actuation nanocomposite wire in which a massive number of Nb nanoribbons with ultralarge elastic strains are loaded inside a shape memory alloy (SMA) matrix to form a continuous array of nanobias actuation pairs for two-way actuation. The composite exhibits a two-way actuation strain of 3.2% during a thermal cycle and an actuation stress of 934 MPa upon heating, which is about twice as high as that (∼500 MPa) found in reported two-way SMAs. Upon cooling, the composite shows an actuation stress of 134 MPa and a mechanical work output of 1.08 × 10(6) J/m(3), which are about three and five times higher than those of reported two-way SMAs, respectively. It was revealed that the massive number of Nb nanoribbons in the compressive state provides the high actuation stress and high work output upon cooling, and the SMA matrix with high yield strength offers the high actuation stress upon heating. Compared to traditional bias-type two-way actuators, the two-way actuation composite with a small volume and simple construct works well with the miniaturization and simplification of actuators.
State Key Laboratory of Heavy Oil Processing, China University of Petroleum , Beijing 102249, China.
Shijie
S
Hao
School of Mechanical and Chemical Engineering, The University of Western Australia , Crawley, Washington 6009, Australia.
Yinong
Y
Liu
X-ray Science Division, Argonne National Laboratory , Argonne, Illinois 60439, United States.
Yang
Y
Ren
State Key Laboratory of Heavy Oil Processing, China University of Petroleum , Beijing 102249, China.
Daqiang
D
Jiang
State Key Laboratory of Heavy Oil Processing, China University of Petroleum , Beijing 102249, China.
Feng
F
Yang
State Key Laboratory for Advanced Metals and Materials, University of Science and Technology , Beijing 10083, China.
Daoyong
D
Cong
State Key Laboratory for Advanced Metals and Materials, University of Science and Technology , Beijing 10083, China.
Yandong
Y
Wang
State Key Laboratory of Heavy Oil Processing, China University of Petroleum , Beijing 102249, China.
Lishan
L
Cui
coupling stress; nanocomposite; nanoribbons; shape memory alloy; two-way actuation