Bio-inspired Adaptive Building Skins - Biotechnologies and Biomimetics for Civil Engineering - page 123

Fig. 5.5 Aero Dimm facade principle. (Source Gruber ( 2011a ), reprinted with permission)

The internal vascular networks, found in most homeothermic living organisms,
form the basis for an innovative adaptive window system, developed at the Wyss
Institute for Biologically Inspired Engineering at Harvard University (Hatton et al.
2013 ). The window is supplemented with an array of very thin transparent water-
carrying channels to act as microfluidic heat exchange layer for thermal control of
the surface (Fig. 5.6 ). By adjusting the flow rate through the system, a dynamic
thermoregulation effect is achieved. The researchers report a cooling effect of
7-9 C at a relatively low flow rate, and expect a significant energy-saving
potential with full-scale facade integration of the new technology (Hatton et al.
2013 ). A further iteration of this product aims at enhanced heat capacity, by
enriching the fluid with phase change materials (PCM) in the form of nanoparticles
(Alston 2014 ).
Despite the growing number of documented examples in the built environment,
flexible, kinetic structures are still more frequently found in nature than in
buildings. Especially the movement observed in plants offers a rich source of
inspiration for technology transfer to buildings. Schleicher et al. ( 2014 ) propose a
methodology for integrating these principles into new components for adaptive
building skins, and demonstrate the potential with three case studies. One of these
is Flectofin , a new type of lamella system that provides adaptive solar shading
through elastic deformation of flexible slats (Lienhard et al. 2011 ). In a slightly
abstracted form, the full-scale integration of this type of bending technology has
already been demonstrated: the ''One Ocean'' Pavilion at EXPO 2012 in Yeosu,
South Korea (Knippers and Speck 2012 ).