Squid-inspired soft superpropulsion
Abstract
Squid span four orders of magnitude in size yet rely on pulsed jets. We show that the funnel (siphon) is a compliant nozzle whose dilation and recoil lag mantle contraction, storing and returning energy within each pulse, a mechanism we term superpropulsion. Histology reveals a collagen sheath, and chromatophore tracking in two squid species quantifies a repeatable phase lag. Engineered nozzles, 3D fluid-structure simulations, and a reduced-order mathematical model predict > 300% impulse amplification when nozzle response time matches jet acceleration (tau/T = 0.2-0.4), overlapping in vivo timing. Tuned nozzles extend jet reach, enhance plume dispersion, and improve jet-driven boat transport, with gains persisting after 40x miniaturization. Superpropulsion recasts pulsed jets as impedance matching, with a soft nozzle acting as an elastic capacitor that passively shapes impulse delivery in soft robotic thrusters and fluidic actuators.
Keywords
Cite
@article{arxiv.2605.03239,
title = {Squid-inspired soft superpropulsion},
author = {Daehyun Choi and Paras Singh and Ian Bergerson and Minho Kim and Jieun Park and Halley J. Wallace and Kenny Zhang and Sandy Y. Hsieh and Aqua T. Asberry and Theodore A. Uyeno and William F. Gilly and Hyungmin Park and Daeshik Kang and Chandan Bose and Saad Bhamla},
journal= {arXiv preprint arXiv:2605.03239},
year = {2026}
}