Scientists in the US have created a robot the size of a fly that is able to perform the agile manoeuvres of the ubiquitous insects.
This "robo-fly", built from carbon fibre, weighs a fraction of a gram and has super-fast electronic "muscles" to power its wings.
Its Harvard University developers say tiny robots like theirs may eventually be used in rescue operations.
It could, for example, navigate through tiny spaces in collapsed buildings.
The development is reported in the journal Science.
Dr Kevin Ma from Harvard University and his team, led by Dr Robert Wood, say they have made the world's smallest flying robot.
It also has the fly-like agility that allows the insects to evade even the swiftest of human efforts to swat them.
This comes largely from very precise wing movements.
By constantly adjusting the effect of lift and thrust acting on its body at an incredibly high speed, the insect's (and the robot's) wings enable it to hover, or to perform sudden evasive manoeuvres.
And just like a real fly, the robot's thin, flexible wings beat approximately 120 times every second.
The researchers achieved this wing speed with special substance called piezoelectric material, which contracts every time a voltage is applied to it.
By very rapidly switching the voltage on and off, the scientists were able to make this material behave like just like the tiny muscles that makes a fly's wings beat so fast.
"We get it to contract and relax, like biological muscle," said Dr Ma.
The main goal of this research was to understand how insect flight works, rather than to build a useful robot.more