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Project Overview

Continuum arms / manipulators are a class of robots with many degrees of freedom, leading to highly flexible motion with inherent compliance. These attributes make them well-suited for manipulation tasks and physical interaction with the environment. However, they also are more difficult to control and less intuitive than traditional manipulator designs.

This page provides open-source designs for continuum manipulators to facilitate research of these unique mechanisms. The designs are low-cost and readily reproducible using off-the-shelf components and 3D-printing. Software is provided for each design so researchers can control the manipulators easily.


  1. Sitler, J., and Wang, L. (2022). A Modular Open-Source Continuum Manipulator for Underwater Remotely Operated VehiclesASME Journal of Mechanisms and Robotics (JMR).

Design Versions


Version 1.0


Files last updated on 10/29/2021.

3D Model Download



  • Underwater continuum manipulator, for use with BlueROV2 or similar underwater ROV.
  • Waterproof enclosure protects the actuation unit and allows for underwater operation.
  • Lead screws provide high mechanical advantage, allowing for large tendon forces to be generated with high backdrive resistance.
  • Arm uses eight links connected by 2 DoF U-joints to create a strong central backbone with very low twist.
  • Spring-loaded continuum arm and Nitinol wire tendons add extra stiffness.
  • 8 IMU's are connected to each link to provide sensory feedback for shape estimation or other applications.
  • Flexible rubber bellows seals the arm and uses weights to achieve neutral buoyancy.
  • 6-inch diameter cylinder.


Version 2.0



Files last updated on 06/16/2022.

3D Model Download


  • Adapted from Version 1.0.
  • 4-inch diameter cylinder.
  • IMU Mux integrated into arm base.
  • Motors changed to smaller Dynamixel XL330-M288-T to fit inside smaller cyliner.
  • Lead screws changed to 1/4"-20 UNC threaded rod for ease of use with standard nuts.
  • Electronics mounting plate redesigned.


Version 3.0


Files last updated on 12/05/2022.

3D Model Download


  • Two segment continuum manipulator.
  • Gearbox designed to utilize larger Dynamixel motors
  • Number of cables per segment changed from 4 to 3
  • Six cables and motors total
  • Electronics mounting plate redesigned


Long Wang

Assistant Prof. Mechanical Engineering

Justin Sitler

PhD Student

Nick Matranga

Undergraduate Student

Byron Panrudkevich

Undergraduate Student

Daniel Liu

Undergraduate Student

Thomas Fallon

Undergraduate Student