Washington, July 8 - Tiny flying machines can survey anything from indoors to collapsed buildings. Now researchers are mimicking nature's small flyers - and developing robotic bats that offer increased manoeuvrability and performance.

Small flyers, or micro-aerial vehicles (MAVs), have garnered a great deal of interest due to their potential applications where manoeuvrability in tight spaces is necessary, said Gheorghe Bunget, North Carolina State University (NCSU) researcher.

'Due to the availability of small sensors, MAVs can be used for detection missions of biological, chemical and nuclear agents,' said Bunget.

But, due to their size, devices using a traditional fixed-wing or rotary-wing design have low manoeuvrability and aerodynamic efficiency.

So Bunget and his advisEr Stefan Seelecke looked to nature. 'We are trying to mimic nature as closely as possible,' Seelecke said, 'because it is very efficient. And, at the MAV scale, nature tells us that flapping flight - like that of the bat - is the most effective.