MASTER THESIS Biomimetic potential of sponge ... - IAP/TU Wien

Biomimetics: Sponges and buildings
Sponge spicules conjoin a variety of interesting properties, ranging from mechanical
stability and flexibility over transparency and other optical features to a sustainable, low
temperature synthesis (Figure 27). Though there have been reports on unexpected optical
behaviour, like the white-to-red shift of light transmitted light through spicules (Figure 20b),
sponge spicules hold promise as stable and flexible light guides. At the same time our
increasingly urbanized environment requires us to design more carefully than ever how we
use light and how we expose ourselves to non-visual effects of light. Spongial skeletons
epitomize a smart way to integrate additional functions into structural elements. Though
siliceous spicules are (if we interpret the evolutionary history of hard skeletons right (cf.
(Huiskes, 2000) (Uriz, 2006)) primarily structural elements, they integrate other
functionalities and physiologically relevant properties (Figure 7). We could learn from this
evolutionary “learning process” regarding integrating structural support and conducting
light. After all, nature has maintained and improved this arrangement throughout more than
500 million years. In fact the symbiosis with microorganisms and the presence of a hard
skeleton were probably the most important factors for the evolutionary success of sponges
(Müller et al., 2007a) Since the symbiosis frequently involves photosynthetic organisms
(Rützler & Muzik, 1993)(Usher et al., 2004), light management is essential for a successful
mutualistic relationship.
In conclusion, sponges exemplify how to successfully integrate structural and light
conducting properties. Their long history and the resulting exposure to changing
environmental conditions they survived maintaining a siliceous skeleton (Müller et al.,
2009c) suggest that this arrangement is very robust and sustainable.
Considering the scale of sponges and the frameworks supporting high rise buildings,
scaling effects and associated problems come to mind immediately. Undeniably the scale of
sponge spicules (3 m long at most in Monorhaphis chuni) and skyscrapers (up to 829 m, Burj
Khalifa) make the suggestion of simple copies sound naïve, and obviously this is not
proposed here. This work suggests the incorporation of principles observed in spongial
skeletons on two different levels.
On a small scale, the structure of sponge spicules is regarded a good role model for
robust glass fibres as desirable for lighting in buildings (Figure 25). Structure as well as
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