Christine rotinat-libersa

Atomic Energy and Alternative Energies Commission | CEA · Digiteo

This paper presents a new millimeter-sized membrane actuator utilizing the volume expansion, resulting from a phase-change composite material, induced by self-heating through the Joule effect. The composite consists of carbon particles as the conductive elements and of paraffin wax as the polymer matrix. The behavior of the actuator is experimental...

The design of Micro Electro Mechanical Systems (MEMS) is often based on the use of costly trial and error method which depends highly on the technical skills of the involved engineers. The drawback of such a procedure is to lead to sub-optimal designs and poor performance at the end. Some research works on dedicated optimization tools have begun a...

A grand variety of microactuator technologies and demonstrators has been introduced during the last years. Of particular interest are the microactuators based on phase change materials and especially paraffin wax, which can volumetrically expand up to 15%, providing high force actuation. The object of this study is the numerical validation o...

In this paper, we present the different steps towards the development of miniature compliant bending joint and gripper with high mechanical performances. These low encumbrance structures (5 mm cross-section) should deliver, with few actuation force, a large output displacement (90° bending, and 60° jaws opening respectively) under large output load...

In this paper, we present the first steps towards the development of a high dexterity hand-held motorized laparoscopic instrument for the realization of complex surgical tasks (e.g. suturing) in areas of difficult access. To produce the required intracorporeal degrees of mobility with sufficient forces, a combination of compliant mechanisms and a l...

In this work, the design modeling and testing of a compact and lightweight hydraulic actuation system is presented. Compared to similar compact actuators found in the literature, our system considerably increases the work density while maintaining an equivalent force-to-volume ratio. An analytical model that is able to accurately predict the quasi-...

This paper reports on the description of a new high force-resolution microgripper with large jaw displacement, electrostatically actuated by a comb-drive and instrumented with an integrated differential capacitive displacement sensor. This microgripper has been non-intuitively designed using a multi-objective optimization method, to reach the best...

In this paper, modeling and robust control strategy for a new control-optimized piezoelectric microgripper are presented. The device to be controlled is a piezoelectric flexible mechanism dedicated to micromanipulation. It has been previously designed with an emphasis to control strategy, using a new topological optimization method, by considering...

This study introduces a comparative performance analysis of the technological solutions that have been used to build distal active articulations for minimally invasive medical procedures. The aim is to provide a practical and concise database and classification tool for anyone that wants to learn more about the technologies involved in minimally in...

Cet article présente une méthode de synthèse optimale de mécanismes flexibles piézoélectriques monolithiques à actionneurs et capteurs intégrés. Il présente en particulier l’établissement du modèle aux éléments finis multiphysiques définissant les blocs capteurs piézoélectriques, et son utilisation au sein du logiciel d’optimisation. Les résultats...

The present paper deals with the concept, design and experimental studies realized for the development of a new generation of bypass grafting devices to be used during minimally invasive procedures. The work has been done in the framework of the BMBF “MISS” project (for “Mini-Invasive Smart Suture”), in collaboration with CEA LIST, a French Carnot...

The project MISS (Minimal invasive smart suture) provides solutions and concepts for several key issues within cardiac surgery. These issues include pre-operative image-based stenosis detection and planning, intra-operative semiautomatic registration and dynamically adapting of video and angiography data, as well as the presentation of two novel co...

1. Abstract This paper presents a new method developed for the optimal design of piezoactive compliant mechanisms. It is based on a flexible building blocks method, called FlexIn, which uses an evolutionary approach, to optimize a truss-like structure made of passive and active piezoelectric building blocks. An electromechan-ical approach, based on...

This paper presents an optimal synthesis method for the preliminary design of monolithic piezoelectric flexible smart mechanisms. The design of such a mechanism, according to this method known as FlexIn, is based on the assembly of structural, active and/or sensing elementary piezoelectric flexible blocks, selected respectively out of three block l...

This paper presents a new method developed for the optimal design of piezoactive compliant micromechanisms. It is based on a flexible building block method, called FlexIn (flexible innovation), which uses an evolutionary approach, to optimize a truss-like planar structure made of passive and active building blocks, made of piezoelectric material. A...

This paper presents a new method developed for the optimal design of microrobotic compliant mechanisms. It is based on a flexible building block method, called Flexln, which uses an evolutionary approach, to optimize a truss-like structure made of building blocks. From the first design step, in addition to conventional mechanical criteria, dynamic...

This paper presents a new method developed for the optimal design of piezoactive compliant mechanisms. It is based on a flexible building blocks method, called Flexln, which uses an evolutionary approach, to optimize a truss-like structure made of passive and active piezoelectric building blocks. An electromechanical approach, based on a mixed fini...

Compared to electric manipulators, hydraulic manipulators can handle very high payloads with respect to their size and mass. However, due to their limitations in force-torque control, they are usually disqualified for precise manipulation. CEA, in collaboration with CYBERNETIX developed a complete remote handling system featuring the advanced hydra...

Cet article présente brièvement deux méthodes d'optimisation pour la synthèse de structures flexibles. La première est une méthode heuristique utilisant des blocs flexibles élémentaires, et la seconde est une méthode d'optimisation déterministe, appelée méthode des courbes de niveaux. Nous illustrons ici l'efficacité de chacune des deux techniques,...

This paper presents a new method to optimally design active compliant mechanisms. It is partly based on a flexible building blocks method called FlexIn, which had been developed at the French Atomic Energy Commission (CEA). This method uses an evolutionary algorithm approach to optimize a truss-like structure, made of an assembly of passive and act...

Maintenance tasks at ITER divertor level require the use of powerful force-reflective remote handling devices. CEA in collaboration with CYBERNETIX and IFREMER has developed the Maestro hydraulic manipulator (Modular Arm and Efficient System for TeleRObotics). For teleoperated tasks inside the ITER vacuum vessel, model-based monitoring of the robot...

The work presented here concerns the design and manufacturing possibility of a polymodular autonomous microrobot moving like an earthworm. The study consists of the development of a new locomotion actuator based on shape memory alloys. This actuator is formed by a flexible frame forced in post-buckling by its assembly on a rigid skeleton cage. This...

Ces travaux entrent dans le cadre des études nécessaires à la mise au point d'une structure déformable actionnée par fils en alliage à mémoire de forme. L'application visée est son utilisation comme module de locomotion d'un microrobot intratubulaire autonome de type “ lombric ”. Un module est constitué d'un cadre élastique carré forcé en post-flam...

The work presented here constitutes an outline of the various studies necessary to develop a new autonomous in-tube exploration microrobot. Constituted by five identical locomotion modules, the future microrobot shall inspect networks of industrial tubes, of diameter lower than 15 mm, and presenting bends and forks. Judicious actuation of the vario...

In this paper, three peculiar in-pipe microrobots are presented. They are the result of investigations of 3 laboratories involved in the microrobotics workgroup of the French National Centre of the Scientific Research (CNRS). They have been conceived to answer the locomotion problem inside industrial tubes of small diameter. Each of them is specifi...