Perpustakaan Digital ITB

Soft robots have been developed to have the advantage of being flexible and compliant so that they can interact safely with humans through the usage of soft materials. However, they also require high stiffness so that they can transmit force and have load-bearing capacity. Layer jamming is one of the existing stiffness modulation methods that utilizes layers of planar structures and an external pressure gradient to couple the layers together which increases its stiffness due to the friction between the layers. Although layer jamming could achieve a high stiffness ratio, this method could only alternate between two states of stiffness, hence a continuous stiffness modulation could not be achieved. On the other hand, soft materials have been shown to have higher stiffness when compressive stress is applied. Thus, this research aims to study the stiffness modulation ability of a layer jamming structure with the addition of a soft material as its core layer. To determine the effect of soft material addition, finite element simulation and experimental validation were conducted by varying the soft material type, thickness, and vacuum pressure. The yield force, bending stiffness, stiffness ratio, and damping were then calculated to compare the effect of soft material addition. The results showed that the addition of DragonSkin 10 and Ecoflex 00-30 as the soft material would modify the initial stiffness and increase the yield force of the structure compared to a regular layer jamming structure, enabling them to maintain its pre-slip phase for a wider deflection and decrease the maximum damping of the structure. Additionally, the simulation showed that an increase in vacuum pressure would slightly decrease the stiffness of the structure and increase the damping, while an increase in the soft material thickness would increase the bending stiffness and yield force of the structure while maintaining relatively constant maximum damping.