Tag Archives: swarms

Not exactly ‘Prey’: self-organizing materials that can mimic swarm behaviour

Prey, a 2002 novel by Michael Crichton, focused on nanotechnology and other emerging technologies and how their development could lead to unleashing swarms of nanobots with agendas of their own. Crichton’s swarms had collective artificial intelligence, and could massive themselves together to take on different macroscale shapes to achieve their own ends. This latest development has nowhere near that potential—not yet and probably never. From a July 21, 2016 news item on ScienceDaily,

A new study by an international team of researchers, affiliated with Ulsan National Institute of Science and Technology (UNIST) [Korea] has announced that they have succeeded in demonstarting control over the interactions occurring among microscopic spheres, which cause them to self-propel into swarms, chains, and clusters.

The research published in the current online edition of Nature Materials takes lessons from cooperation in nature, including that observed in honey bee swarms and bacterial clusters. In the study, the team has successfully demonstrated the self-organizing pattern formation in active materials at microscale by modifying only one parameter.

A July 21, 2016 UNIST press release, which originated the news item, expands on the theme,

This breakthrough comes from a research, conducted by Dr. Steve Granick (School of Natural Science, UNIST) of IBS Center for Soft and Living Matter in collaboration with Dr. Erik Luijten from Northwestern University. Ming Han, a PhD student in Luijten’s laboratory, and Jing Yan, a former graduate student at the University of Illinois, served as co-first authors of the paper.

Researchers expect that such active particles could open a new class of technologies with applications in medicine, chemistry, and engineering as well as advance scientists’ fundamental understanding of collective, dynamic behavior in systems.

According to the research team, the significance of team work was stressed by both Dr. Luijten and Dr. Granick as this current breakthrough is part of a longtime partnership using a new class of soft-matter particles known as Janus colloids, which Dr. Granick had earlier created in his laboratory. The theoretical computer simulations were completed by the team, led by Dr. Luijten and Dr. Granick used these colloids to experimentally test the collective, dynamic behavior in the laboratory.

The micron-sized spheres, typically suspended in solution, were named after the Roman god with two faces as they have attractive interactions on one side and negative charges on the other side.

The electrostatic interactions between the two sides of the self-propelled spheres could be manipulated by subjecting the colloids to an electric field. Some experienced stronger repulsions between their forward-facing sides, while others went through the opposite. Along with them, another set remained completely neutral. This imbalance caused the self-propelled particles to swim and self-organize into one of the following patterns, which are swarms, chains, clusters and isotropic gases.

To avoid head-to-head collisions, head-repulsive particles swam side-by-side, forming into swarms. Depending on the electric-field frequency, tail-repulsive particles positioned their tails apart, thus encouraging them to face each other to form jammed clusters of high local density. Also, swimmers with equal-and-opposite charges attracted one another into connected chains.

Dr. Granick states, “This truly is a joint work of the technological know-how by the Korean IBS and the University of Illinois, as well as the computer simulations technology by Northwestern University.” He expects that this breakthrough has probable application in sensing, drug delivery, or even microrobotics.

With this discovery, a drug could be placed within particles, for instance, that cluster into the delivery spot. Moreover, alterations in the environment could be perceived if the system unexpectedly switches from swarming to forming chains.

Here’s a link to and a citation for the paper,

Reconfiguring active particles by electrostatic imbalance by Jing Yan, Ming Han, Jie Zhang, Cong Xu, Erik Luijten, & Steve Granick. Nature Materials (2016)  doi:10.1038/nmat4696 Published online 11 July 2016

This paper is behind a paywall.

Swarming robot droplets

The robot droplets are a bit bigger than you might expect, the size of ping pong balls, but the idea is intriguing and for those who’ve read Michael Crichton’s book, Prey, it could seem quite disturbing (from the University of Colorado Boulder multimedia page for ‘tiny robots’),

For anyone unfamiliar with Crichton’s Prey, here’s an excerpt from the Wikipedia entry about the book which features nanobots operating as a swarm,

… As a result, hazardous elements such as the assemblers, the bacteria, and the nanobots were blown into the desert, evolving and eventually forming autonomous swarms. These swarms appear to be solar-powered and self-sufficient, reproducing and evolving rapidly. The swarms exhibit predatory behavior, attacking and killing animals in the wild, using code that Jack himself worked on. Most alarmingly, the swarms seem to possess rudimentary intelligence, the ability to quickly learn and to innovate. The swarms tend to wander around the fab plant during the day but quickly leave when strong winds blow or night falls.

The Dec. 14, 2012 posting by Alan on the Science Business website describes,

A computer science lab at University of Colorado in Boulder is building a miniature, limited-function robot designed to work in a swarm of similar devices. Computer science professor Nikolaus Correll and colleagues are building these small devices that they call droplets as building blocks for increasingly complex systems.

A University of Colorado Boulder Dec. 14, 2012 news release provides more details,

Correll and his computer science research team, including research associate Dustin Reishus and professional research assistant Nick Farrow, have developed a basic robotic building block, which he hopes to reproduce in large quantities to develop increasingly complex systems.

Recently the team created a swarm of 20 robots, each the size of a pingpong ball, which they call “droplets.” When the droplets swarm together, Correll said, they form a “liquid that thinks.”

To accelerate the pace of innovation, he has created a lab where students can explore and develop new applications of robotics with basic, inexpensive tools.

Similar to the fictional “nanomorphs” depicted in the “Terminator” films, large swarms of intelligent robotic devices could be used for a range of tasks. Swarms of robots could be unleashed to contain an oil spill or to self-assemble into a piece of hardware after being launched separately into space, Correll said.

Correll plans to use the droplets to demonstrate self-assembly and swarm-intelligent behaviors such as pattern recognition, sensor-based motion and adaptive shape change. These behaviors could then be transferred to large swarms for water- or air-based tasks.

Correll hopes to create a design methodology for aggregating the droplets into more complex behaviors such as assembling parts of a large space telescope or an aircraft.

There’s also talk about creating gardens in space,

He [Correll] also is continuing work on robotic garden technology he developed at the Massachusetts Institute of Technology in 2009. Correll has been working with Joseph Tanner in CU-Boulder’s aerospace engineering sciences department to further develop the technology, involving autonomous sensors and robots that can tend gardens, in conjunction with a model of a long-term space habitat being built by students.

Correll says there is virtually no limit to what might be created through distributed intelligence systems.

“Every living organism is made from a swarm of collaborating cells,” he said. “Perhaps some day, our swarms will colonize space where they will assemble habitats and lush gardens for future space explorers.”

The scientists don’t seem to harbour any trepidations, I guess they’re leaving that to the writers.