Robots come to the rescue after WTC collapse

Following the collapse of New York`s twin World Trade Centre towers in September, a team of small, mobile robots was drafted in to help rescuers search otherwise inaccessible spaces under the rubble. The shoebox-sized robots, developed at the Centre for Robot-Assisted Search and Rescue and at the University of South Florida, arrived at the disaster zone a day after the terrorist attack which led to the collapse.

Over the following 11 days, the robots made several forays into the piles of rubble, using on-board sensors to look for body heat or coloured clothing. They were able to enter crevices that were too small or dangerous for human rescuers or dogs to enter. They helped to find five bodies.

The robots, each costing $10,000-40,000, were controlled via tethers that gave them an operating range of more than 30m.

US researchers started to develop search-and-rescue robots following the Oklahoma City bombing. One technology they are working on uses a "mother" robot which carries smaller devices as far as she can into a collapsed building before releasing them to examine smaller crevices.

They are also hoping to develop tether-free systems with enough on-board intelligence to guide themselves through collapsed buildings and other awkward terrains. Dr Robin Murphy, a computer scientist from South Florida University, is developing algorithms that would allow the robots to distinguish colours and shapes to identify victims more easily.