Semi-automated micro assembly for rapid prototyping of a one DOF surgical wrist

We have developed new methods for the automated assembly of prototype structures and we illustrate them with the construction of a simple one DOF 5mm surgical wrist employing polyester flexures instead of revolute joints. The first step in the structural assembly involves the construction of hollow stainless steel triangular beams that are used for the rigid elements of the structure. It includes the development of a folding fixture to bend stainless steel sheets and the determination of a folding angle sequence by static analysis using a compliant mechanism model. The semi-automatic process of using a millirobot (orthotweezers) to manipulate and assemble the beams and attach the flexures is described in detail. The paper ends with a description of the procedure used to design the wrist.