An aperture composed of 3D-printed, humidity-responsive surfaces.
ICD University of Stuttgart. An aperture composed of 3D-printed, humidity-responsive surfaces.

In "The Architecture of the Well-Tempered Environment" (University of Chicago Press, 1969), historian Reyner Banham argues that "of all the factors involved in environmental management, humidity has, for the most of architectural history, been the most pestiferous, subtle and elusive of control." The invention and widespread implementation of air conditioning has obviously functioned to counteract undesirably high levels of humidity—while humidification technologies have fulfilled the opposite goal of adding moisture to dry air.

In recent years, researchers at the University of Stuttgart's Institute for Computational Design (ICD), in Germany, have been pursuing another humidity-related agenda. But rather than temper humidity, they are developing architectural envelopes that respond it.

This aim is evident in the ICD's 2012 HygroScope installation in Paris and the 2013 HygroSkin Pavilion in Orléans, France, both of which feature moisture-sensitive wood panels that expand and contract with shifts in relative humidity. Unlike conventional adaptive systems for temperature or moisture regulation—which are typically mechanized endeavors—these surfaces represent a material solution, and thus require no electricity or additional moving parts.

This month, the ICD announced another breakthrough in humidity-responsive envelopes in the form of a 3D-printed, biomimetic architectural system. Like its earlier wood veneer–based composite systems, the digitally fabricated surfaces demonstrate high sensitivity to relative humidity changes. However, they are also tunable, and may be programmed with a wide range of responsiveness. In a statement on the project, the team says that the new surfaces "embody the capacity to sense, actuate and react to climatic changes, all within the material itself."

As light and thermal regulation systems in architecture become increasingly complex, the new development suggests a promising future for a simpler, material-based approach—without the obligatory, electricity-dependent sensors, actuators, controllers, and their attendant wiring and processing equipment.

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.