Social insects and swarm robotics

One of the most remarkable characteristics of social insects, including honey bees, is their ability to perform complex tasks as a group that a single individual would not be capable of.  For example, both ants and social bees have evolved sophisticated colony-level mechanisms for gathering large quantities of food, despite being relatively simple organisms.  Even more impressively, honey bee swarms will collectively choose the most optimal location in the surrounding area to build their new hive, making a democratic decision that benefits the colony as a whole.  As scientists discover more about the way social insect groups function, these findings can lead to novel approaches to solving problems in other fields.  One such emerging discipline is swarm robotics.

Kilobots – small, inexpensive autonomous robots that perform tasks as a group.

Swarm robotics, which began to develop in various research labs worldwide over the past decade, aims to apply the decision making and task performing capabilities of groups of social insects to a variety of applications.  Systems of small, relatively simple autonomous units are generally more cost-effective and easier to design than a single more complex centrally controlled machine.  And a significant advantage of swarm robots over traditional robots is their robustness – when one individual component of the system fails in a swarm, the numerous other components that are capable of performing the same function will ensure only a small loss of productivity.  Swarm robots, therefore, could be used in more variable environments or with less supervision than larger, more complex machines.

A squadron of swarm-bots traverses uneven terrain.

A range of applications have been envisioned for swarm robotics: exploration of other planets or remote environments on Earth, such as the deep-sea floor; diagnosis or treatment of disease or even non-invasive surgery, delivered to the human body by nanobots; search-and-rescue missions; clean-up after a toxic waste spill or a natural disaster; repair of damaged coral reefs; targeted application of pesticides in farming; and even artificial crop pollinators to compensate for declining honey bee populations.  Swarm robotics systems that have been implemented by various labs so far include a system of heterogeneous components that can self-assemble to perform various tasks; small, cheap, simple robots that can aggregate into specific formations to move large objects; and sleek self-constructing block formations reminiscent of LEGO towers.

There are, however, many hurdles to be overcome before swarm robotics reaches its envisioned potential.  A robot that operates without easy access to a charging station, such as inside the human body or in an inhospitable environment, will need a long enough battery life to perform its assigned tasks on one charge.  For example, the flight of honey bees is so energetically demanding that the best present-day battery that can fit inside a robotic bee could only sustain the robot's flight for ten to fifteen seconds – orders of magnitude short of the battery life required for an artificial pollinator to be effective.  Furthermore, current implementations of swarm robots must be programmed to perform a specific task by a central command unit, which we do not directly observe with social insects in nature.  However, according to evolutionary theory, organisms are "programmed" to propagate their genes into further generations, whereas we create swarm robots to perform other, more specific, tasks that are beneficial to humans.  One could imagine a future in which swarm robots are also self-replicating and therefore able to perform their assigned task indefinitely, without supervision, as hybrid machine-organisms.  (At that point, we must be careful not to make our autonomous, self-replicating robots too intelligent, to prevent the robot uprising that science fiction has warned us about.)

A robo-bee prototype developed at Harvard University.

While swarm robotics today is still in its infancy, it has huge potential for expanding our knowledge about the world, improving our quality of life, and ameliorating ecological problems.  As energy storage technology improves and more research labs get involved in this field, we can expect to hear more and more about advancements in swarm robotics in the coming years.