Design of configuration indifferent compliant building blocks

Abstract

Here we introduce an approach for designing flexure-based building blocks that achieve certain degrees of freedom (DOFs), which remain unchanged regardless of how the building blocks are arranged (i.e., configuration indifferent building blocks). The approach leverages the geometric shapes of the freedom and constraint topologies (FACT) approach, which embody the mathematics of screw theory. Specifically, only nine of FACT's shape types can be used to design such configuration indifferent building blocks, and this work details the guidelines for synthesizing the viable options from within those shapes. Multiple case-study examples are generated and fabricated using the guidelines introduced. Configuration indifferent building blocks are important because they can be repeated within compliant motion stages or metamaterials to achieve desired directions of high compliance (i.e., DOFs) without concern for how they are assembled together.