Squid-inspired soft superpropulsion

Daehyun Choi; Paras Singh; Ian Bergerson; Minho Kim; Jieun Park; Halley J. Wallace; Kenny Zhang; Sandy Y. Hsieh; Aqua T. Asberry; Theodore A. Uyeno; William F. Gilly; Hyungmin Park; Daeshik Kang; Chandan Bose; Saad Bhamla

arXiv · 2605.03239

Squid-inspired soft superpropulsion

Daehyun Choi·Paras Singh·Ian Bergerson·Minho Kim·Jieun Park·Halley J. Wallace·Kenny Zhang·Sandy Y. Hsieh·Aqua T. Asberry·Theodore A. Uyeno·William F. Gilly·Hyungmin Park·Daeshik Kang·Chandan Bose·Saad Bhamla

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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.

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Daehyun Choi, Paras Singh, Ian Bergerson, Minho Kim, Jieun Park, Halley J. Wallace, Kenny Zhang, Sandy Y. Hsieh, Aqua T. Asberry, Theodore A. Uyeno, William F. Gilly, Hyungmin Park, Daeshik Kang, Chandan Bose, Saad Bhamla. 2026-05-05. Squid-inspired soft superpropulsion. https://arxiv.org/abs/2605.03239

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