The biological phenomenon of flocking has long fascinated scientists. The ability of hundreds or more individual organisms to move in concert towards a common objective remains a scientific mystery. An unnamed 17th-century poet wrote: “...and the thousands of fishes moved as a huge beast, piercing the water. They appeared united, inexorably bound to a common fate. How comes this unity?”
More recently, science writer James Gleick reported in Nature's Chaos (Viking, 1990) that "High-speed film reveals that the turning motion travels through the flock [of birds] as a wave, passing from bird to bird in the space of about one-seventieth of a second. That is far less than the bird’s reaction time.”
Some scientists believe that the way to solve the flocking enigma is to replicate it. Researchers at Harvard University’s Wyss Institute and School of Engineering and Applied Sciences (SEAS) recently developed a micro-scaled robotic technology that enables a controlled, flash mob–like assembly. In August, the team led by Harvard computer-science professors Radhika Nagpal and Fred Kavli demonstrated the ability of 1,000 robots to self-organize into user-selected shapes, such as a five-pointed starfish and the letter K.
"The beauty of biological systems is that they are elegantly simple—and yet, in large numbers, accomplish the seemingly impossible,” Nagpal said in a press release. "At some level you no longer even see the individuals; you just see the collective as an entity to itself.”
In 1928, ant expert William Morton Wheeler labeled a collective activity of multiple organisms a “superorganism,” owing to the apparently single-minded nature in which such flocks operate. For this robotics project, Wyss Institute and SEAS research associate Michael Rubenstein offers the example of rafts and bridges formed by army ant colonies in order to negotiate challenging terrain. "Biological collectives involve enormous numbers of cooperating entities—whether you think of cells or insects or animals—that together accomplish a single task that is a magnitude beyond the scale of any individual,” he said in the press release.
Called Kilobots, the Wyss robots move much slower than ants and birds, and only in two dimensions (across a flat horizontal surface). Moreover, poor positioning and traffic jams are common outcomes, which the researchers have largely solved by improving algorithmic instructions. Nevertheless, potential for improvement exists.
"Increasingly, we're going to see large numbers of robots working together, whether it's hundreds of robots cooperating to achieve environmental cleanup or a quick disaster response, or millions of self-driving cars on our highways," Nagpal said in the press release. "Understanding how to design 'good' systems at that scale will be critical.”
One provocative concept is the possibility of building and infrastructure construction that is carried out by thousands of self-organizing modules. Although many technical hurdles remain, this notion is especially intriguing in the case of hazardous and other challenging settings. In the near term, we will likely witness simple, one-story pavilions built from a collection of mobile robotic bricks to create emergency relief shelters following natural disasters.
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.
