@article{parra-rubio-alfonso-MS-2021, title = {Discrete Continuum Robotic Structures}, , language = {en}, author = {Parra Rubio,Alfonso}, }

Abstract

When overcoming environmental constraints, nature shows the capacity to generate hybrid hard-soft morphing continuum structures at very low cost at almost any scale. Human attempts to replicate nature-like systems to overcome modern engineered solutions, based on classical rigid mechanics, commonly lead to hyper-redundant and complicated designs. Novel trends like soft robotics or continuum robotics are showing new successful directions but mostly at small sizes. It is still a challenge to achieve accessible and cost-efficient scalable nature-like solutions.

The earliest research towards digital materials focused on proving reversibility of their assembly, their low relative densities vs. ultra-high stiffness ratios and scal- ability properties. Now we can find architected metamaterials with many kinds of exotic physical properties. This thesis will focus on digital materials with custom mechanical properties. Recent work showed the capacity to generate controlled me- chanical anisotropies as embedded compliancy, chirality, and auxeticity. That enables generating continuum macroscopic foams with controlled deformation that could pre- serve some properties and help bring simplicity to overcome tasks that, with classic rigid-joint mechanical systems, would require a very complex system.

Equally important, many of the modern engineering solutions that would require digital materials are very dependent on their outer shape. Literature shows less acclaim for providing an accurate shape to these digital materials. Some of the strategies proposed have been based on hierarchical strategies or reducing the overall size of the building blocks but these findings conflict with the many of the claimed premises. This thesis is proposing a folded solution that will integrate onto the continuum structure and provide a desired shape that is structurally efficient while respecting its intrinsic degrees of freedom.

As a whole, this thesis explores if heterogeneous digital materials can provide all the mechanical needs of a movable structure integrated. This thesis tries to mimic nature’s engineering strategies by joining the kinematical and shape-form needs into a single material system composed of a discrete building block core and a folded outer- mold-line layer. As examples, this thesis recreates a water snake and a morphing wing inspired by birds camber morphing