Everyone knows about the current rage for biomimetics - the building of machines or robots which copy design features from living creatures. But now a top UK biomech boffin has hurled cold water over the whole idea.
"My work should act as a reminder to be cautious in copying nature," says Dr Jim Usherwood of the Royal Veterinary College.
In particular, Usherwood is sceptical of the various research and development schemes which seek to mimic the flight of birds, bats, insects etc. He has spent years analysing the flapping wings of dragonflies, quail and most recently racing pigeons. (Usherwood's test pigeons apparently have to carry lead fishing weights to check their performance, and fly with reflective tape spots all over them so that their wing oscillations can be precisely monitored.)
In essence, Usherwood says that the dumb chums use flapping wings, not because it's a good or efficient flight mechanism, but because it's the only one you can make out of living bones, skin, feathers etc. Compared to ordinary aeroplanes, helicopters etc, birds, bats and insects are basically crap. Usherwood's research was presented at the Society for Experimental Biology's Annual Meeting in Marseilles over the weekend.
"Humans have always wanted to fly," says the the RVC release. "First attempts involved imitation of winged creatures around them, and unfailingly ended in disaster. No workable flying machines have ever looked particularly similar to nature's fliers."
"There is lots of interest in making MAVs/UAVs (micro/unmanned air vehicles) that flap," adds Usherwood. "There is a tendancy to presume that biology is efficient. I would say that, even at very small sizes, if you want to hover efficiently, be a helicopter not a flapper ..."
The doc says that flapping is a fairly rubbish way to do business, because you waste so much energy defeating the wing's inertia. On every beat, the wing must twice be sped up then decelerated to a stop. But an aeroplane wing, a propellor blade or a helicopter rotor all keep moving all the time. They only have to be accelerated once.
"Think of ... the exuberant rattling of a cocktail shaker - this takes a fair amount of power to overcome inertia," says Usherwood. "The effort of flapping ... explains why vultures don't look like gliders, and why most winged creatures, from insects to pigeons, fly so inefficiently."
Given the exuberant cocktail-shaking illustration and the pic Usherwood has chosen for his personal webpage, it seems safe to say that Usherwood enjoys a cheerier and more mainstream lifestyle than the stereotypical biomimetics boffin. He seems more intuitively trustworthy than the sinister misfits who have sought funding for such notions as the "gargoyle mode" robot spy bat-thopter, the extremely buggy bug-bug, the mechanoid mole cruiser, "Bigdog" walking petrol mule etc.
Interestingly, one might note that biomimetic projects are thus far confined mainly to the world of academe, where funding is often related to the attention an idea can grab rather than any prospects it may have of genuinely being useful. Why, it's almost as though there was some kind of media-related thing going on here, with idle hacks and researchers feeding the public a stream of animal-related, headline-friendly projects when they ought to be doing (and reporting on) proper engineering.
But that's a really far-fetched idea. ®