2 Design of the Multi-module Manipulator

In Chapter 1 all the suitable technologies have been surveyed and a direct comparison underlined how fluidic technologies have the best characteristics to meet the application scenario. In particular, flexible fluidic actuators have been identified as the most promising technology for providing omnidirectional bending and elongation, while granular jamming can represent a valid solution to implement variable stiffness features. In this chapter, we report the design of the single module, the strategy for integrating more modules, the fabrication and characterization of a 2-module manipulator. 2.1 The Design of the Single Module Each module of the manipulator has to be able to independently perform omnidirectional bending, elongation, and stiffening. This is possible thanks to two different actuation systems integrated in each module: flexible fluidic actuators combined with a chamber exploiting the granular jamming mechanism. The main component of the manipulator module is an elastomeric cylinder (silicone EcoflexTM 0050, Smooth-on Inc.). This material guarantees the right level of softness when deformed passively and it is suitable to host internal chambers that can be used to modulate the characteristics and the behavior of the module. The cylindrical elastomer hosts three equally spaced chambers which are embedded in radial arrangement (the fluidic actuators) and another one centrally placed (for granular jamming) as shown in