If you’re interested in building real-world robot swarms, the unit cost is everything. Reportedly, most commercial swarm bots cost $100 or more, sothis innovative design from Michael Rubenstein, Nicholas Hoff, and Radhika Nagpal of the Harvard’s Self Organizing Systems Research Group represents an order-of-magnitude savings over existing platforms. They call it “Kilobot,” and besides low cost, it is designed for rapid assembly (<5 min/unit) and group charging using plates that engage the top and bottom of the entire swarm at once.