Researchers at the University of Edinburgh have achieved a new method of 3D printing for soft-bodied robotics that can be produced in mass amounts. Instead of requiring the assembly of multiple parts like traditional methods, this new technique allows for the creation of a four-legged robot in a single piece, which then can walk out of the print machine.
In March, a one-piece soft-bodied robot was printed in 3D at UC San Diego in a 58-hour process. The six-legged robot was powered by compressed air, which enabled it to move its legs forward.
The new four-legged robot designed by scientists at the University of Edinburgh is also air-driven. However, it only takes nine hours to print. Furthermore, while the San Diego robot was made using a $1,000 printer, the Edinburgh bot uses an open-source platform called the Flex Printer, constructed from readily available components and costing approximately $500.
Like its American predecessor, the Scottish robot is also crafted entirely out of soft, flexible thermoplastic polyurethane (TPU), a material known for its challenging printing characteristics. The scientists overcame two major hurdles associated with TPU: buckling and drooping.
Buckling, the tendency of the extruded filament to deviate from its intended path, was mitigated by employing a wider-diameter filament. The more significant challenge of drooping, caused by gravity acting on the molten TPU, was ingeniously addressed by inverting the printing process.
Instead of extruding the TPU downwards onto a print bed, the Flex Printer pushes the material upwards. This innovative approach leverages gravity to press each new layer of TPU onto the preceding one, promoting fusion and structural integrity. Once printing is complete, the robot is detached from the print bed and flipped right-side up.
The bot is then connected to a device known as a pneumatic ring oscillator, which delivers a pulsating 2.25-bar (32.6-psi) air current into channels within the robot’s body. This air pressure sequentially activates ligament and foot actuators in each leg, resulting in lateral movement and lifting of the limbs, enabling the robot to walk.
While the current robot serves primarily as a demonstrator, the implications of this open-source technology are far-reaching. By removing manufacturing and design bottlenecks, this method paves the way for the broader development and application of soft-bodied robots in diverse fields such as exploration, medicine, and search and rescue operations.
Image & Article source by The University of Edinburgh
