A butterfly-stroke-like soft robotic swimmer that is fast and efficient

The researchers from North Carolina State University have recently developed a fast and efficient soft robotic swimmer that swims resembling human’s butterfly-stroke style. It can achieve a high average swimming speed of body length per second, close to five times faster than the fastest similar soft swimmers, and also a high-power efficiency with low cost of energy. The small-sized swimmer is light weight and only has 2.8 grams. It has a soft body and a pair of bistable flapping wing. The design of the wing is inspired by the bistable hair clips. The soft body can bend up and down driven by pressurized pneumatic air, which consequently drives the fast flapping of the wings via snapping, a phenomenon often observed in Venus flytrap. The work is recently published on Science Advances, titled “Snapping for high-speed and high-efficient butterfly stroke-like soft swimmer“ by Y. Chi et al., Sci. Adv. 8, eadd3788 (2022) on Nov. 18, 2022. The open access paper can be found at