A new material that can transform its permeability, transparency, and hydrophobicity in real-time.
Courtesy the Wyss Institute A new material that can transform its permeability, transparency, and hydrophobicity in real-time.

Tears perform a range of complex activities: they wash away particulates, protect the eye from airborne dust, and provide an optically-enhancing liquid coating. Scientists at Harvard's Wyss Institute for Biologically Inspired Engineering looked to tears for inspiration in developing a new material that can "tune" its relationship with liquids by adjusting the size of its micropores.

The new adaptive substance, which is comprised of several layers of films and adhesives, is capable of changing multiple properties when stretched. When a lubricant is added to the material in a resting state, it becomes transparent. The material is also slippery, and liquid droplets roll off freely. Once stretched, however, the material not only becomes more opaque, but also prevents liquid from moving further—even counteracting gravitational forces.
According to Wyss Institute postdoctoral fellow Xi Yao, the material offers much more than "switchable wettability" in that it offers a superior degree of control—capable of manipulating the actions of individual liquid droplets in real-time. For this reason, the research team is excited about the possibilities of creating new applications such as: smart pipelines that automatically regulate the flow of fluids, self-cleaning contact lenses, or architectural textiles that can adjust their transparency and permeability based on varying weather conditions.
From an architect's perspective, given the increasing importance of water resources and storm water management in buildings, this new tear-inspired discovery could generate architecture that "cries" as it adjusts to changing circumstances.

Blaine Brownell, AIA, is a regularly featured columnist whose stories appear on this website each week. His views and conclusions are not necessarily those of ARCHITECT magazine nor of the American Institute of Architects.