Journal Article 27FC46GA44 3D printing Arsenicals Biocompatible Materials CH46OC8YV4 Gallium Letter Research Support, Non-U.S. Gov't Silk auxetic auxetics biomaterials discrete structure gallium arsenide high sensitivity mechanical damage endurance mechanical metamaterials mechanoluminescence memristors molecular dynamics simulations on-skin electronics photonic skin silk proteins stretchable devices stretchable electronics stretchable strain sensors