Calibration of a multi-mobile coil magnetic manipulation system utilizing a control-oriented magnetic model

International audienceIn this paper, we address the calibration of a family of magnetic manipulation systems composed of several coils that are moved around by serial robot manipulators. We show in this paper that the calibration of the whole system ultimately results in calibrating the manipulator and coil separately up to an unknown rigid transformation. For calibration of the coil, we propose to use a model that has not been used so far in the literature; a control-oriented model which is su ciently accurate and computes the magnetic field in real time. A protocol for calibrating the magnetic manipulation system using the Nelder-Mead algorithm to estimate the model parameters is presented. Calibration was performed through simulations and validated experimentally on a physical system. It was observed that the root mean square error was reduced by 37% after calibration of the physical system, indicating an improvement in accurately estimating the magnetic model

Visual servoing of a laser beam through a mirror

International audienceIn this study, we present a new approach to improving vocal fold access to perform phonomicrosurgery. It is done by shooting the laser through a mirror to reach the vocal fold hidden parts. A geometrical study of laser shooting path was conducted for vocal fold anatomical constraints, followed by devising a laser-shooting system conceptual design. Control laws were developed and tested by simulation and validated experimentally on a test bench in a monocular and stereoscopic configuration. Simulation and experimental results are provided to demonstrate the effectiveness of the developed approac

Study and implementation of electrostatic actuation for programmable matter modules

International audienceActuation of micro-robots in relation to the field of programmable matter has been the aim of most researches working on the topic. Most studies have concentrated on the ability of these robot modules to latch with one another and to be able to move around each other to form the desired configuration. These mostly have been based on Modular Self re-configurable Robots (MSR) which use mechanical, magnetic or pneumatic method in their manoeuvres. However, these have been faced by the challenges of miniaturization, power consumption and power transfer between modules. Electrostatic actuation has attracted more interest in recent works due to the ability to scale down the modules and to use the configuration for power transfer and communication. In this work, we propose to use electrostatic chuck principle to actuate modules having a cylinder form. Instead of using one array of electrodes, two columns of electrodes array, positive and negative, are considered to increase the force generated by the chuck effect. An array of electrodes prototype has been fabricated using lithography process for validating the actuation. A sufficient force and torque are generated for latching and making the cylinder rolling respectively, thus validating and showing the potential of electrostatic actuation for miniaturized programmable matter application.</span&gt</font&g

Topology optimization of piezoelectric structures : micro-actuators and energy harvesters

International audienceThis paper reviews the primary research effortsconducted within the AS2M department of the FEMTO-STinstitute, focusing on topology optimization of piezoelectricstructures. The paper primarily highlights the principle andthe possibilities offered by topology optimization with aspecific emphasis on the SIMP approach (Solid IsotropicMaterial with Penalization). Then, the design processes ofpiezoelectric micro-actuators and energy harvesters are described.The optimized piezoelectric structures are presentedand the improvements over classical designs are assessed.Finally, the paper discusses the feasibility and the potentialof multi-material topology optimization

In-situ phase control of a low-loss membrane-based lithium-niobate polarisation-state modulator

International audienceWe report on lithium niobate intermediate-thin films with reducedenergy-manufacturing costs for manufacturing low-loss electro-opticcomponents. A micrometer-thick membrane surrounded with tapers isinscribed in a single step by smoothly dicing the bottom face of astandard LiNbO<sub&gt3</sub&gt electro-optic modulator. Hence, wedemonstrate a freestanding polarisation-state modulator withinsertion losses as low as 2.6 dB. The in-situ structuring of themembrane allows a giant phase control extending over 40°. Thesedevelopments open the way to a new generation of membrane-basedelectro-optic devices with low manufacturing-energy costs andreduced yield losses for sensing, telecommunications, or quantumphotonics applications