Nature often finds the most efficient routes of creating actuation activity for reconfiguration, adaptation and reproduction [1]. “Living Beings” is a result of inspiration from natural activity and properties of wood such as its structural consistency and moisture absorption. Bound water to the wood, expands the hygroscopic wood cell walls [2]. This results in an overall expansion of the wood structure at higher relative humidity environments, just like a breathing creature, knitted wooden structures demonstrate a water exchange behavior in which they switch from one conformational equilibrium state to another. This equilibrium state transformation is a consequence of water absorption within wood microstructure and voids. This results in an energy release in the form of a movement, creating an active structure. The dynamics of its movements are coded within its geometrical constraints which is the knitted structure. The transition process of the knitted wooden structures in their geometric form is often reversible. Such active beings get affected by their environment and do affect their environment in a back and forth interaction. The novelty of their knitting design comes from the encoded action within and the activity that is a consequence of their interaction with the humidity of their environment.

Furthermore, such structures can have applications, as sensors of atmospheric changes, bio-inspired muscles, environmental manipulators and active architectural structures. Additionally, in applications where consistency and static behavior is necessary, various knitting designs can create strong or elastic structures, for spacers and load bearing applications and wherever light weight and/or porosity is of interest. Experimental scalability and design of the knitted wood structures is of interest for applications in larger dimensions. Scale based functionality is another aspect of these structures as the warp and weft inherent properties and dimensions define the structural pores, density and mechanics and further their application potential.

References

[1] Le, X., Lu, W., Zhang, J., Chen, T., “Recent Progress in Biomimetic Anisotropic Hydrogel Actuators”. Adv. Sci. 6, 1801584 (2019).

[2] Harrington, M., Razghandi, K., Ditsch, F. et al. “Origami-like unfolding of hydro-actuated ice

plant seed capsules”. Nat Commun 2, 337 (2011).

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