Researchers at the State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University (XJTU) have proposed a new strategy for realizing multiple mechanochromic behaviors based on dynamic manipulation of surface wrinkling.

Using an extremely simple SiOx/PDMS material system, different types of mechanochromic effects were achieved by ingeniously controlling the force-responsive dynamic wrinkled surface, namely brightness mechanochromism, hue change mechanochromism, and viewable angle mechanochromism.

These force-responsive wrinkled surfaces have potential applications in smart displays, as well as privacy and anti-counterfeiting technology.

The strategy the researchers used has a simple preparation process with advantages of low cost, excellent material reversibility and stability, which gives it potential commercial prospects.

The research was published in Nano Letters under the title Reversible Mechanochromisms via Manipulating Surface Wrinkling. (Link to the paper: https://pubs.acs.org/doi/10.1021/acs.nanolett.1c04494)

Associate Professor Wu Kai from XJTU, Zhu Ting, a XJTU doctoral student, and Associate Professor Zhu Liangliang from Northwestern University are the co-first authors of the paper. Professor Liu Gang and Professor Sun Jun are the co-corresponding authors. Professor Chen Xi from Columbia University also participated in the research. The State Key Laboratory for Mechanical Behavior of Materials is the only communication unit.

The research was financed by the National Natural Science Foundation of China.

Many animals (such as chameleons and octopuses) can change the color or transparency of their skin by adjusting the micro/nano structure of the epidermis through muscle activity when they are stimulated by the environment. This is done for camouflage and communication.

Inspired by this, researchers can use photolithography or self-assembly techniques to fabricate micro/nano surface structures or micro/nanoparticle arrays, which can induce a mechanochromic effect due to the change of the micro/nanoperiodic structure under stress.