Air compressors have provided the energy needed for the first ‘untethered soft robot’ to take its first tentative steps, in a journal article published in the latest issue of Soft Robotics.

Engineers at Harvard and Cornell Universities in the USA constructed the robot out of durable silicone, which is strong enough to contain the relatively high air pressures needed to power its movement.

The octopus-like quadraped operates at pressures of up to 138 kPa, and is strong enough to carry the air compressors on its back, along with a payload of up to 8kg.

It is highly durable, and able to withstand exposure to surface water, snow, being run over by a typical automobile, and even limited exposure to flames.

At 65cm in length, it is relatively large compared to previous robots built in a similar way, and in addition to the air compressors and any payload, it also carries its own battery, valves and controller.

Thanks to its soft construction, it is safe to interact with, and represents a significant advance from the same team’s previous design, which was tethered to external air compressors.

However, it is not yet clear what the practical applications of the robot might be – and at little over $1,000 to build, it may ultimately find a home as a gadget-lover’s pet.