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Highlights • Concentric tube robots (CTR) are interesting for surgical applications. • Evaluation of stability and number of equilibria for given actuation inputs remains difficult. • A generic numerical framework for cardinality and stability assessment is proposed. • Continuation method, dynamic relaxation and bifurcation analysis are associated. • Accuracy of the framework is demonstrated by generating reference results. • New results about 3-tube CTR follow-the-leader deployment are presented. Abstract Concentric tube robot (CTR) is a promising class of continuum robots for medical interventions given their compactness and dexterity. Their dexterity is in particular being used to achieve so called Follow-the-Leader (FTL) deployments, where the tip path draws the shape of the robot. During this kind of deployment they can however be subject to elastic instabilities, and the number of reachable configurations may vary for a given state of actuators. These cardinality and stability changes need therefore to be predicted during CTR design. Available methods and results are limited, with restrictive assumptions on number and properties of tubes. We therefore propose in this paper a numerical framework for the cardinality and stability assessment of CTR. It is based on the association of dynamic relaxation, continuation method and bifurcation analysis. The numerical framework is validated by reproducing reference results on the stability and cardinality of two-tube robots. Then, new results on three-tube CTR deploying in a FTL manner are presented. The framework genericity allows in particular to provide new insights on the behaviour of CTR with helical-shaped tubes. [ABSTRACT FROM AUTHOR]

Abstract: This work presents a novel approach to the development of MOEMS devices by robotic micro-assembly of individual microoptical components onto reconfigurable free-space micro-optical table (RFS-MOT). Various micro-optical elements (e.g. microlenses, micromirrors) are integrated within a generic structure of silicon holders. The holders are manipulated by 3D microassembly station with active microgripper, then aligned with nanometer precision within the guiding rails of silicon baseplate, and finally fixed by release of integrated mechanical snap connector. The fabrication of RFS-MOT components involves bulk micromachining of standard silicon wafer (baseplate) or SOI wafer (holders). The design and technology of RFS-MOT is presented. The successful micro-assembly of holders is demonstrated as an experimental validation of the proposed approach. The new method for measuring of position of assembled holder, based on laser triangulation displacement sensor, is described. [ABSTRACT FROM AUTHOR]