Journal Article Research Support, Non-U.S. Gov't carbon nanotubes 3D printing BEH3 Comparative Study Drought tolerance Nanotubes, Carbon Poplar Transgenic poplar aerogels carbon nanotube sponge chemical vapor deposition electronic skin flexible electronics graphene nanoribbon heterostructures high actuation stress and strain interpenetrated network low threshold low-shrinkage machine learning mechanoluminescence multiscale features nanocomposite actuator nanocomposites nanomaterials scalable 3D assembly shape memory polymer tactile sensing