Multi-Responsive Surface Via Wrinkling

A bilayer film composed of a thin polymer film atop thick elastomer substrate was prepared. Reversible switching between wrinkled and flat surface can be achieved by a facile stretch and release method. This system shows a very high opaqueness as released from a small strain (ca. 5%), which leads to a potential application for smart windows. By altering the chemical composition of the polymer thin film, simply applying moisture can also instantaneously induce a wrinkled surface, which can be reversed as the moisture is removed. The alignment of wrinkle pattern can be achieved through coordinating with mechanical strain. Selective inducing chemical modification on the polymer thin film surface can create patterned wrinkles, which is expected to lead to specific applications.