Giant shape-memory effect in twisted ferroic nanocomposites

TL;DR

This paper demonstrates a novel twisted ferroic nanocomposite design that exhibits a giant shape-memory effect with over 10% recoverable strain, overcoming size limitations of traditional alloys for nanoscale actuators.

Contribution

The authors introduce twisted ferroic nanocomposites that significantly amplify domain switching strain, enabling large shape-memory effects at the nanoscale.

Findings

Achieved >10% recoverable strain in nanoscale ferroic oxides.

Twisted architecture amplifies ferroelectric domain switching strain.

Overcomes size limitations of traditional shape-memory alloys.

Abstract

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.