Famous robotics company iRobot - maker of the noted Roomba autonomous floor-cleaner and supplier of war-bots to the US military - has announced a radical new development contract. The company is to create a "soft" robot able to wriggle its way through "openings smaller than its actual structural dimensions".

It almost goes without saying that the $3.3m in military blobotics funding comes from DARPA, the Pentagon boffin collective which is to the established military-technological paradigm what stun grenades are to tea-parties.

“During military operations it can be important to gain covert access to denied or hostile space,” said Dr Mitchell Zakin of DARPA, suggesting that the squashy machines are intended to penetrate physical security covertly.

“We believe that a new class of soft, flexible, meso-scale mobile objects that can identify and maneuver through openings smaller than their dimensions to perform various tasks will be quite valuable".

“Consistently [tackling] challenges with robots has made us a trusted DARPA partner,” said Helen Greiner, co-founder and chairman of iRobot, offering a shrewd hint as to the best way of becoming friends with the radical military brainboxes.

The new flexi-penetration bot programme has been dubbed ChemBots. It was originally announced last year, as a modification to a wider enabling-techniques push, but nothing further was made public until now.

DARPA requires that the final $3.3m prototype machine:

Travel a distance Traverse an arbitrary-shaped opening much smaller than the largest characteristic dimension of the ChemBot Reconstitute size, shape, and functionality after traversing the opening Travel a distance again Perform a function using the embedded payload

The Phase One version, which iRobot are now embarked upon, should be "approximately the size (but not necessarily the form-factor) of a regulation softball" which can move 5 metres in 20 minutes, pass through a 1cm opening and reassume its original shape in 15 seconds. Roughly speaking, then, we're talking about a cricket-ball sized job which can get through a keyhole. This might open up a few backdoors, in a security sense.

DARPA don't care how this is done, but they do note that "nature provides many examples of ChemBot functionality ... mice, octopi, and insects readily traverse openings barely larger than their largest 'hard' component".

The paradigm-punishing boffins reckon that the squidgy mechanoids could make use of "gel-solid phase transitions", "shape-memory", "magneto-rheological materials" or - perhaps rather more credibly - "geometric transitions, eg, folding". That last might be the one to bet on, perhaps combined with miniature, deflatable balloon tyres.

One might also note that payload and function are agreeably non-specific, and that many explosives - just for instance - are available in liquid or gel form. It would probably be within the rules of the game for the robot to simply blow up or release a gas in order to "perform a function".

But iRobot is an imaginative company, and makes lovely robots. (Even if the machines aren't all that good at cleaning floors.) It can probably come up with something a bit more cunning. ®