Wood and the Activity of Dead Tissue

Abstract

Wood is a prototypical biological material, which adapts to mechanical requirements. The microarchitecture of cellulose fibrils determines the mechanical properties of woody materials, as well as their actuation properties, based on absorption and desorption of water. Herein it is argued that cellulose fiber orientation corresponds to an analog code that determines the response of wood to humidity as an active material. Examples for the harvesting of wood activity, as well as bioinspiration, are given.

Functional packaging of seeds

“…As stiff, bundled polymer chains, known as microfibrils, cellulose can direct moisture‐dependent volume changes and modulate the mechanical properties (notably strength and stiffness) of the entire fibre and fibrous tissues (summarized by Eder et al . (2020)). This is achieved by varying the angle of cellulose microfibrils in the secondary cell wall with respect to the fibre long axis (scheme in Fig.…”

“…If fibres are present, their orientation with respect to each other and their wall structure are important, because both parameters induce directionality (anisotropy) in terms of the mechanical properties and hygroscopic deformations – see summaries by Gibson (2012) and Eder et al . (2020). Broadly speaking, plants exploit fibre anisotropy for functional control, particularly for force generation.…”

The sustainability of phytomass-derived materials: thermodynamical aspects, life cycle analysis and research perspectives

“…A bias would be to ignore that some low-tech realizations are scientifically challenging, as illustrated by hygromorphic materials (cladding, for instance) that can be used in passive responsive architecture. [250][251][252][253] Since the sustainability of bio-based materials is fundamentally dependent on transformation processes, one solution could be to focus on low-tech transformation processes as well. Field retting is such an example in which wind, rain and naturally occurring soil microorganisms help to fractionate stem fibres prior to further processing and defibrillation.…”

Gozd in les 2021: podnebne spremembe: znanstveno srečanje: Ljubljana, 25. maj 2021

“…Les je naravni in obnovljivi material, ki ima odlične mehanske lastnosti in je lahko dostopen. Skozi zgodovino je les veljal za najpomembnejši gradbeni material (Eder, 2020). Glavne slabosti lesa so njegova nagnjenost k biološki razgradnji in gorljivost (Sandberg in sod., 2017).…”