Design of a unidirectional water valve in Tillandsia

Raux, Pascal S.; Gravelle, Simon; Dumais, Jacques

Abstract

The bromeliad Tillandsia landbeckii thrives in the Atacama desert of Chile using the fog captured by specialized leaf trichomes to satisfy its water needs. However, it is still unclear how the trichome of T. landbeckii and other Tillandsia species is able to absorb fine water droplets during intermittent fog events while also preventing evaporation when the plant is exposed to the desert's hyperarid conditions. Here, we explain how a 5800-fold asymmetry in water conductance arises from a clever juxtaposition of a thick hygroscopic wall and a semipermeable membrane. While absorption is achieved by osmosis of liquid water, evaporation under dry external conditions shifts the liquid-gas interface forcing water to diffuse through the thick trichome wall in the vapor phase. We confirm this mechanism by fabricating artificial composite membranes mimicking the trichome structure. The reliance on intrinsic material properties instead of moving parts makes the trichome a promising basis for the development of microfluidics valves.

Más información

Título según WOS: Design of a unidirectional water valve in Tillandsia
Título según SCOPUS: Design of a unidirectional water valve in Tillandsia
Título de la Revista: NATURE COMMUNICATIONS
Volumen: 11
Número: 1
Editorial: NATURE PORTFOLIO
Fecha de publicación: 2020
Idioma: English
DOI:

10.1038/s41467-019-14236-5

Notas: ISI, SCOPUS - ISI