The US Army’s next generation of battle robots might not take inspiration from humanoid prototypes such as Atlas, developed for the military by Boston Dynamics, but from worms and snails instead.
In a paper published in the journal Extreme Mechanics Letters, a team from the US Army Research Laboratory and the University of Minnesota detail new developments in the fast-growing field of “soft robotics” – where machines are built not of steel, but of highly compliant plastics.
The researchers, led by mechanical engineer Ghazaleh Haghiashtiani, reveal the creation of a new design for an actuator – a device that converts energy inputs into movement. Most actuators used in robotics are either electrical, pneumatic or hydraulic.
The new one is made from a combination of a type of synthetic polymer called an elastomer and ionic hydrogel. It has two distinct advantages over other designs. First, it can be made through 3D printing, and, second, running an electrical current through it causes it to bend into many different shapes.{%recommended 6647%}
The actuator – the first of many military creations using soft robotics – represents an early step towards tackling what the army sees as a significant drawback arising from deploying current Atlas-style robots in battle situations.
Existing robots tend to be big and solid and comparatively inflexible. They stand out in a crowd and have difficulty manoeuvring in urban warfare environments. They also require rigid and complicated circuitry, which adds bulk and introduces vulnerabilities.
Soft, flexible robots, on the other hand, have the potential to move around covertly, slide through narrow openings and even, to some extent, repair themselves if damaged.
“Successful stealthy manoeuvring requires high structural flexibility and distributive control to sneak into confined or restricted spaces, operate for extended periods and emulate biological morphologies and adaptability,” explains co-author Ed Habtour.
To research how this might be achieved Haghiashtiani and his team focussed on organisms that are naturally soft and bendy.
“In the initial phase of the project, our team began by investigating new methods for emulating the locomotion of invertebrates, which provided fundamental insights into the machineries of their soft distributed actuation circuitries that allow for high bending motions without skeletal support,” says researcher Michael McAlpine.
And while the current actuator serves only as proof-of-concept, it potentially points to a future in which robotic warfare becomes, if anything, even more sinister than it already seems. In years to come, perhaps, the sight of a gun-wielding, two-metre high Atlas will seem oddly reassuring.
“The research findings represent an important stepping stone towards providing the solider an autonomous freeform fabrication platform – next-generation 3-D printer, which can print functional materials and devices – to generate soft actuators and potentially tetherless soft robots on demand, on the fly and at the point of need,” says Habtour.
