1 / 19

Guns, Jellyfish, and Steel

Guns, Jellyfish, and Steel. Why we should mimic jellyfish for efficient underwater propulsion. Cyro – biomimic jellyfish robot. Guns? I thought this was bioE !. Why does a gun recoil?. How is a submarine propelled?. How does a jellyfish propel itself?. (Naïve?) Propulsion M odel.

questa
Download Presentation

Guns, Jellyfish, and Steel

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Guns, Jellyfish, and Steel Why we should mimic jellyfish for efficient underwater propulsion

  2. Cyro – biomimic jellyfish robot

  3. Guns? I thought this was bioE! Why does a gun recoil? How is a submarine propelled?

  4. How does a jellyfish propel itself?

  5. (Naïve?)Propulsion Model Time = t Time = t+Dt u+Du u V-DV V M - Dm M j-u

  6. Model v. Experiment Little jellyfish (prolates) Big jellyfish (oblates) Big D !!!

  7. Vortex complexesIncrease Efficiency

  8. Biomimetic Robot Design • Features to replicate? • How to do this simply? • Bell material properties: buoyancy, elasticity • Bell geometry/deformation • Muscles/Actuation

  9. Hard body vs. soft-body Infinite degrees of freedom (DOF) Finite degrees of freedom (DOF)

  10. Action and Reaction: SMAs Shape Memory Alloys (SMA) Stress, strain and heating

  11. Crystal structure phase change • Temperature induced phase change: • Martensite: soft, plastic, easily deformable state • Austenite: much harder material, rigid/difficult to deform.

  12. Reaction: Spring steel and elastomer • SMA changes length metal does not

  13. 3-D printed mold: Integrating actuators

  14. The devil in the details No-flaps Flaps

  15. Computer control: Feedback SMA contracts  Changing resistance Monitored by computer Adjusts current flow through SMA

  16. Mimic vs. Nature

  17. Up, up, and away

  18. Small modifications go a long way! Flaps and segments lead to large increased in thrust

  19. References Jellyfish Propulsion Mechanisms • S. Colin and J. Costello. Morphology, swimming performance and propulsive mode of six co-occuring hydromedusae. J. Exp Biol.205 (2002) 427-437. • J. Dabiri et al. Flow patterns generated by oblate medusan jellyfish: field measurements and laboratory analyses. J. Exp Biol.208 (2005) 1257-1265 Bioinspired Jellyfish Robot (Robojelly) • A. Villanueva et al. A biomimetic robotic jellyfish (Robojelly) actuated by shape memory alloy composite actuators. Bioinsp. Biomim6 (2011) 036004 • A. Villanueva et al. A bio-inspired shape memory alloy composite (BISMAC) actuator. Smart Mater. Struct.19 (2010) 025013

More Related