Manufacturing of Flexible Metallic Aerogel by Ice-Templated Assembly of Nanowires and Its Applications

This paper presents the manufacturing of flexible and robust metallic aerogels through the ice-templating process. The aerogels are composed of 1D nanomaterials such as silver nanowires (AgNWs) and cellulose nanofibers (CNFs) that are aligned parallel to the growth direction of ice crystals. The formation of hydrogen bonds between CNFs and AgNWs significantly improves compressive elastic modulus and yield strength of the aerogel up to 543% and 444%, respectively. As a result, our aerogels exhibit unique characteristics, including anisotropic structure, low density, high porosity, low resistivity, high elastic modulus, and high yield strength. Finally, we demonstrate the utilities of aerogels as piezoresistive force sensors and electrothermal vacuum pressure sensors. Our approach overcomes the conventional brittleness of aerogel and extends its applications to multifunctional sensors.