Researchers at Cornell and Imperial College London (the paper lists authors including Tian Lan, Atar Babgei, Luca Romanello, Mirko Kovac and Sophie F. Armanini) built MOSS, an amphibious robot with 3D-printed origami wheels that switch between contracted and expanded shapes. A crank mechanism changes wheel width, body diameter and fin orientation at once, completing the switch in 1.95 ± 0.11 seconds, according to the arXiv preprint posted October 19, 2026.
The team tested MOSS on soil, sand, mud at different water content, and open water, plus in-motion morphing and transitions between terrestrial and aquatic surfaces. Which configuration used less energy depended on the ground underneath it.
| Configuration | Where it won |
|---|---|
| Contracted | Lower cost of transport on firmer soil and mud |
| Expanded | Up to 29% lower cost of transport on wetter mud, sand, and water |
| Expanded | Reduced slip in wet mud |
| Expanded | Reduced slip and hub sinkage in sand |
The expanded wheel’s gain is framed only as a cost-of-transport reduction relative to the contracted form, not an absolute efficiency figure, and the paper does not state the wheel material, print process, or robot mass. Outdoor trials are mentioned as confirming operation across natural deformable terrain and water, but no outdoor numbers are given.
The result lines up with other work showing that letting a 3D-printed structure change shape in use, rather than optimizing one fixed geometry, is where the printing process earns its keep: the IMDEA and UPM team got similar mileage out of single-step printed braided nitinol stents that compress 50% and recover 90%. The paper is an ICRA 2027 submission, so these are preprint numbers, not peer-reviewed ones yet.