Programmable soft robotic arms with auxetic metamaterials

In recent years, auxetic materials with their unique mechanical properties and wide application potential have become an important research focus in the field of materials science. Auxetic patterns, which are suitable for use in soft robot applications, offer many advantages over traditional mechanism techniques, such as the ability to remove part numbers, no wear, and no corrosion of the materials used. In this study, the deformation of the structure was examined by designing a tubular soft robot to give a predetermined movement and pneumatically actuating it, using the mechanical properties of auxetic patterns. Silicone was cast through molds manufactured using additive manufacturing methods, and pneumatic was used to drive the resulting structure. The difference of this research from other tests done in the literature is that the pressure is applied only to the top cover, in the direction of longitudinal extension, not to the inner walls, in order to ensure the movement of the tubular structure without changing its diameter. It is noteworthy that while the deformation of the tubular structure took the targeted shape after the applied pressure, the dimensional change in the diameter of the tubular structure was around one percent. This study presents a new concept in designing and actuating tubular soft robots using auxetic patterns. Using this concept in future studies makes it possible to achieve the desired movement with an auxetic design. This potential has the capacity to provide solutions in the medical sector, space research and many other fields.