Engineering news
Developed at the University of California San Diego (UC San Diego), the six-legged walking machine is instead powered by compressed gas. It can be 3D-printed in one go using a single material, its creators said in an announcement yesterday (25 March), and can walk “right off the 3D printer” after the addition of the gas cartridge.
Researchers in the Bioinspired Robotics Laboratory aimed to use the simplest technology available: a desktop 3D printer and an off-the-shelf printing material. This design approach is not only robust, they said, but also cheap – each device costs about $20 to manufacture.
“This is a completely different way of looking at building machines,” said Professor Michael Tolley from the UC San Diego department of mechanical and aerospace engineering, senior author of a new paper on the work.
Described as a robot by its developers, the machine has simple internal controls for walking and no external controls. A “pneumatic oscillating circuit“ controls the repeated motions of soft actuators, similar to the mechanism that drove locomotive steam engines. The circuit coordinates the movement of the six legs by delivering air pressure at the right time, alternating between two sets of three legs. The legs are capable of moving in four degrees of freedom – up and down, forward and back – which enables them to walk in a straight line.
The device could be used in settings where electronics cannot function, the researchers said. They could be used for scientific reconnaissance in areas with strong radiation or risk of spark ignition, or for environmental monitoring or disaster response.
The team tested the machines in the laboratory, showing that as long as they were connected to a source of gas under constant pressure, they could keep functioning non-stop for three days. They also showed that the robots could walk untethered outdoors, using a compressed gas cartridge as a power source, and traverse different surfaces, including turf and sand. They can even walk underwater.
The biggest challenge was creating a design that would include artificial muscles and a control system, printed with one soft material in a single print. The team, led by postdoctoral scholar Yichen Zhai in Professor Tolley’s research group, adapted a 3D-printing technique they had previously used to build an electronics-free gripper.
Next steps include finding ways to store the compressed gas inside the robots and using recyclable or biodegradable materials, they said. They also plan to explore ways to add manipulators such as grippers to the devices, which were initially developed three years ago.
The work was published in Advanced Intelligent Systems.
Want the best engineering stories delivered straight to your inbox? The Professional Engineering newsletter gives you vital updates on the most cutting-edge engineering and exciting new job opportunities. To sign up, click here.
Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.