A biomimetic robotic jellyfish (Robojelly) actuated by shape memory alloy composite actuators

Bioinspir Biomim. 2011 Sep;6(3):036004. doi: 10.1088/1748-3182/6/3/036004. Epub 2011 Aug 18.


An analysis is conducted on the design, fabrication and performance of an underwater vehicle mimicking the propulsion mechanism and physical appearance of a medusa (jellyfish). The robotic jellyfish called Robojelly mimics the morphology and kinematics of the Aurelia aurita species. Robojelly actuates using bio-inspired shape memory alloy composite actuators. A systematic fabrication technique was developed to replicate the essential structural features of A. aurita. Robojelly's body was fabricated from RTV silicone having a total mass of 242 g and bell diameter of 164 mm. Robojelly was able to generate enough thrust in static water conditions to propel itself and achieve a proficiency of 0.19 s(-1) while the A. aurita achieves a proficiency of around 0.25 s(-1). A thrust analysis based on empirical measurements for a natural jellyfish was used to compare the performance of the different robotic configurations. The configuration with best performance was a Robojelly with segmented bell and a passive flap structure. Robojelly was found to consume an average power on the order of 17 W with the actuators not having fully reached a thermal steady state.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Alloys / chemistry*
  • Animals
  • Biomimetic Materials*
  • Computer Simulation
  • Computer-Aided Design
  • Elastic Modulus
  • Equipment Design
  • Equipment Failure Analysis
  • Models, Biological
  • Robotics / instrumentation*
  • Scyphozoa / physiology*
  • Ships*
  • Swimming / physiology*


  • Alloys