To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video Movie S4. Spandex fibers and PDMS matrix have weak adhesion. When the composite is pulled to a stretch around 1.4, the crack starts to grow. As the crack runs in the matrix, the fibers remain intact and slide against the matrix. A:B = 30:1 for the matrix. Stretchable materials of high toughness and low hysteresis Zhengjin Wang, Chunping Xiang, Xi Yao, Paul Le Floch, Julien Mendez, and Zhigang Suo PNAS. 2019. 116:5967-5972 DOI: 10.1073/pnas.1821420116 Download Original Video Browse All Videos »