Swarms of mini robots that 'bloom' could lead to adaptive architecture

 
Nature is, of course, the master engineer—been there, seen it, solved it. While we struggle to design buildings that don't overheat or feel like concrete cages, nature has been perfecting comfortable living structures for ages. Now scientists are borrowing from the natural world again; this time, to build a swarm of interconnected mini-robots that could lead to buildings with dynamic facades that respond to sunlight and the people inside.

Scientists from Princeton University and Northwestern University were motivated by the frustration that buildings are essentially static boxes that don't move. Yet in nature, some structures are constantly changing, such as ants linking their bodies to form a bridge that changes shape with the terrain.

The team's idea was to use swarm intelligence (the collective behavior of self-organized systems such as schools of fish moving as one) to create a "living" skin for buildings.

The paper is published in the journal Science Robotics.

'Swarm Garden'

The researchers built a system of individual units called SGbots, tiny modular robots with sensors and a wireless radio for communicating with their neighbors. Instead of gears and hinges, each robot has a soft actuator that pulls a flexible plastic sheet through a ring, causing it to "bloom" like a flower in response to environmental stimuli.

As the researchers describe in the study, they built an array of 40 SGbots, which they dubbed "The Swarm Garden."

Real-world testing

To see how their innovation could work in a real building, the team attached 16 of these bots to a sunny office window for several days. When the sun was strong, they extended their sheets together ("bloomed") to block sunlight, and as the sun weakened, the robots gradually buckled their sheets to let more light in.

The scientists also simulated sensor failures and communication breakdowns, and the system remained robust enough to adapt. Because the robots talk to each other, a bot with a broken sensor could still follow the lead of its neighbors.

"The Swarm Garden exemplifies how architectural swarms can transform the built environment, enabling 'living-like' architecture for functional and creative applications," wrote the research team in their paper.

Dancing partner

In a second test, the team set up an array of 36 robots in a public gallery to see how they would respond to human movement. A dancer wore a wearable device that let the swarm mimic her movements.

"The system created a 'partnership defined by negotiation,' making the swarm feel 'alive' and inspiring new forms of creative expression," the researchers stated.

The scientists successfully demonstrated how their robots could be used for adaptive shading and interior design. Next, they want to work with architects to assess the feasibility of using the arrays in the real world on a larger scale.