Meeting Abstract
Epiphytic orchids absorb water and nutrients passively via specialized aerial roots, which contain a spongy outer layer of dead cells known as the velamen radicum. When exposed to precipitation, this layer saturates within seconds and can retain water for hours, acting as a temporary reservoir for the orchid. Until now, no attempt has been made to replicate the aerial orchid root structure for passive fluid transport. Here, we investigate the physical structure of roots using optical microscopy and SEM. We also measure the relative humidity uptake of roots in a sealed container to determine whether roots can condense water vapor. In addition, we characterize the fluid distribution behaviors of root sections and detached velamina using fluorescent video imaging. Initial results indicate that fluids spread rapidly across the surface area of the velamen with a consistent time dependence and without significant directional bias. The relative humidity tests show that orchid roots do not condense water vapor, suggesting an entirely passive fluid absorption mechanism. These results demonstrate that the aerial orchid root structure shows potential for fluid transport applications, such as fluid redistribution in diapers or water harvesting in arid environments.
