Receptive Skins envisions a living building that silently interacts with air and temperature

Imagine a house that interfaces with the people inside it. As you walk through the rooms, the walls part to become doorways; as the sun moves and the temperature changes throughout the day, the house opens and closes to ventilate itself. Rather than a standard “smart” home that’s adjusted electronically through a smartphone or control module, this house modulates its own environment through a pneumatic interface—the air itself interacts with the walls.  

This is the vision that led recent grad Chrisoula Kapelonis (MS'18) to create Receptive Skins, a theoretical approach to rethinking the materials and construction of building envelopes.  The project shows a proof-of-concept of a “breathing” wall that modulates the environment of an interior space via a pneumatic interface. By setting aside the traditional notion of a building as a static artifact, Receptive Skins assumes that a building can be an organic, living interface. 

Weightless origins
Architect and designer Kapelonis focuses on bringing novel disciplines and materials into how we think about spaces–she’s particularly fascinated with the idea of atmosphere as interface. Inspired by the historic Cunningham Sanitarium (an experimental “clean air” treatment center built like a scaled-up hyperbaric chamber to treat patients ambiently), Kapelonis studied pneumatics as a technique for exploring the potential of air in architecture. During her first year as a grad student in the City Science group at the MIT Media Lab, she developed pneumatic wearables and speculative architectures to explore the potential for pneumatics as an interface. The first project to incorporate them in an architectural context was Spatial Flux, which she co-created with fellow City Science group member Carson Smuts.

The team conceived the Spatial Flux project in response to a call for research projects for the Media Lab Space Exploration Initiative’s inaugural zero gravity flight. Kapelonis and Smuts wanted to consider the spatial and architectural challenges of space flight and a weightless environment. They decided to build a responsive, hybrid wearable/architectural interface for anchoring a person in a zero-gravity environment. During the painstaking prototyping phase for Spatial Flux, combining silicone and pneumatics in new ways, Kapelonis got the idea for Receptive Skins, which would become her master’s thesis project.

Fun with thermochromics
There was often leftover liquid silicone from the prototyping experiments with Spatial Flux, and just for fun, Kapelonis would mix the leftovers with a multitude of materials —thermochromic pigments, concrete, phosphorescent pigments, anything that might produce a surprising result—to create new hybrids.This experimentation started her thinking about the potential for new types of material substrates as architectural interfaces.

Another key takeaway from the Spatial Flux project was the unpleasant reality of traditional pneumatics. In order for a pneumatic interface to work, it needs to be pumped full of air; this is generally done through an electronic pump. Kapelonis found the contrast jarring. “This quiet, soft inflatable had to depend on such loud and mechanical means to activate. I kept thinking that there had to be another way to keep the softness and quiessence of the silicone unit with an inflation actuator that was also respectful to the material system,” she says. “This curiosity led to experimentation with new means and materials for inflation, such as using the bi-product of yeast respiration, or phase-changing of a low-boiling-point liquid.”

Kapelonis designed and built prototypes that use both chemical and biological solutions to actuate instead of electronics. The Receptive Skins prototype is made of a silicone substrate mixed with active pigments—thermochromics with different temperature thresholds—and embedded with either low-temperature phase-changing liquids or respiring yeast in order to inflate—producing closed-loop pneumatic systems. The materials within the silicon sense the confluence of sunlight and ambient temperature and react: opening when ventilation is needed, and closing when it is not. The process is silent, as ambient as the air it’s sensing.

A calm house
In steering away from mechanical actuation, Kapelonis is embracing the concept of “calm technology,” an increasingly popular pursuit among designers. “The idea is that technology should not demand our attention, but instead live in the periphery, and allow us to focus on the things that are most important to us,” says Kapelonis. “I resonate deeply with these principles because as an architect, the concept of quiessence is one of the most important qualities of designing space—architecture should always live in the periphery, acting as the stage, not the focus, of our daily lives.”

Kapelonis envisions a fusion of calm technology and architecture as an alternative to traditional digital interfaces. “Technology becomes even more amplified when these interfaces are brought into the home and start to surround our daily lives, so we need to be sensitive to what that means. Mark Weiser believed that the traditional concept of the ‘smart’ home makes the computer too much the center of attention. The principles of calm technology instead call for interfaces that support, but do not distract from, our daily lives,” she says.

Future
The Receptive Skins prototype is smaller than it would need to be in order to modulate environments. The material is difficult to work with, and like concrete, it is not easily changed once it cures. But recent breakthroughs in 3D fabrication processes allow for printing of multi-material substrates, and materials like silicone. Kapelonis hopes that this technology may soon be up to the scale and accuracy needed for the building industry. The project’s scale is also currently limited by the availability of “smart” materials and, even more so, of biological and chemical materials for actuation.

“My hope is that more and more people will start to ‘design’ their own materials, and that crafting materials will become as ubiquitous as designing spaces,” Kapelonis says.