Ultra Low-Cost Printable Folding Robots.

Current techniques in robot design and fabrication are time consuming and costly. Robot designs are needed that facilitate low-cost fabrication techniques and reduce the design to production timeline. Here we present an axial-rotational coupled metastructure that can serve as the functional core of a low-cost 3D printed walking robot. Using an origami-inspired assembly technique, the axial-rotational coupled metastructure robot can be 3D printed flat and then folded into a final configuration. This print-then-fold approach allows for the facile integration of critical subcomponents during the printing process. The axial-rotational metastructures eliminate the need for joints and linkages by enabling locomotion through a single compliant structure. Finite element models of the axialrotational metastructures were developed and validated against experimental deformation of 3D printed units under tensile loading. As a proof-of-concept, an ultra low-cost 3D-printed metabot was designed and fabricated using the proposed axial-rotational coupled metastructure and its walking performance was characterized. A top speed of 4.30 mm/s was achieved with an alternating stepping gait at a frequency of 0.8 Hz.