====== Multiple Degrees of Freedom ======

A collection of known methods to achieve multiple degrees of freedom with soft actuators.

===== - Three lumen fiber-reinforced soft actuator =====

Kevin C. Galloway has created a [[http://www.kevincgalloway.com/portfolio/multi-dof-soft-actuator/|multi-DOF bending soft actuator]] made out of "three independent fiber-reinforced, tube-shaped, linear actuators".

===== - Flexible Microactuator =====
Already in 1989, the lab of Koichi Suzumori in Tokyo have created an [[https://www.youtube.com/watch?v=kHGLYRUKWeM|FMA - Flexible Microactuator that]] operates in 7 degrees of freedom. It is made from 3 separate air chambers and one whole fiber reinforcement.

Paper: {{ :soft-robotics:fma.pdf |}}

===== - Adjustable Stiffness Layers =====
The Swiss Reconfigurable Robotics Lab - EPFL have designed a [[https://www.youtube.com/watch?v=VRyAeyC0GZY|2-DOF soft actuator]] that uses an adjustable stiffness layer. The layer uses two smart memory polymers in each side, that become stiff when heated.

Paper: http://ieeexplore.ieee.org/document/7353510/

===== - Multi-Module Variable Stiffness Manipulator =====
The lab at harvard had produced a [[http://softroboticstoolkit.com/mmvsm|multi-multimodule manipulator with a controllable stiffness]], a bio-design inspired by the octopus.
 
===== - Embodied Intelligence Octopus Arm =====
The BioRobotics Institute in Italy have published a design for an [[http://ieeexplore.ieee.org/document/6224696/|octopus arm]]. It uses Shape Memory Alloys, joined by electrical wires for [[https://www.youtube.com/watch?v=TW3XMPi_wng|infinite degrees of freedom]].

===== - Trefoil Tentacle =====
Matthew Borgatti created a trefoil tentacle with powder printed molds. The instructions are found on [[http://www.thingiverse.com/thing:92103|thingiverse]].