The shape recovery ability of shape-memory alloys vanishes below a critical size (~50nm), which prevents their practical applications at the nanoscale. In contrast, ferroic materials, even when scaled down to dimensions of a few nanometers, exhibit actuation strain through domain switching, though the generated strain is modest (~1%). Here, we develop free-standing twisted architectures of nanoscale ferroic oxides showing shape-memory effect with a giant recoverable strain (>10%). The twisted geometrical design amplifies the strain generated during ferroelectric domain switching, which cannot be achieved in bulk ceramics or substrate-bonded thin films. The twisted ferroic nanocomposites allow us to overcome the size limitations in traditional shape-memory alloys and opens new avenues in engineering large-stroke shape-memory materials for small-scale actuating devices such as nanorobots and artificial muscle fibrils.
@article{arxiv.2206.05364,
title = {Giant shape-memory effect in twisted ferroic nanocomposites},
author = {Donghoon Kim and Minsoo Kim and Steffen Reidt and Hyeon Han and Hongsoo Choi and Josep Puigmartí-Luis and Morgan Trassin and Bradley J. Nelson and Xiang-Zhong Chen and Salvador Pané},
journal= {arXiv preprint arXiv:2206.05364},
year = {2023}
}