Solid Biofoams like Wood

Mimicking natural biological structures allows us to exploit tried design concepts for advanced material solutions. Wood is an example of an interesting natural material to replicate, as it exhibits excellent anisotropic mechanical properties and also performs well as a thermal insulator. We demonstrate a process of creating a cellular structure similar to natural wood -- a solid foam -- from forest-derived bio-constituents (M. Reichler et al., Sci. Reports 11,1 (2021)). As such, the resulting material has anisotropic mechanical properties such as elastic modulus and yield stress and exhibits complex mechanical response similar to natural wood. The heat conductivity is low due to the low density and closed pore structure. This novel paper recyclable material can be used as a substitute for oil-based packaging and insulation foams such as expanded polystyrene or polyurethane.