Towards snake-like soft robots: Design of fluidic fiber-reinforced elastomeric helical manipulators

Tendril helical motions and snake robots have a multitude of potential applications from climbing to anchoring to complex manipulation in fields such as medical, gas/oil energy, and manufacturing. Constructing a snake robot from a fluid driven, fiber reinforced elastomeric enclosure (FREE), complex helical motions are created in a lightweight, low cost, simple structure. The snake-like manipulators are created by forming a hollow cylindrical elastomer that is reinforced with two families of fibers and one additional fiber. The manipulator is then driven by changing the volume of fluid contained within, thus forming the desired helical patterns. The design of this continuum structure is analyzed for all possible fiber angles and the FREE radius. The parameters of the resulting helix including pitch and radius are determined analytically, without the need for finite element methods. Three prototypes at different points in the design space are fabricated and tested to verify the analytical model.