Publications de Florent Cosandier

Three-beam constant-force flexure-based translation stage

Flexure-based constant-force mechanisms belong to the category of zero-stiffness mechanisms. They present a non-zero elastic restoring force which does not depend on the deformation of the mechanism. However, their design and modeling are frequently comple ...

2025

Dynamic balancing of a flexure-based Watt's linkage horological oscillator

Simon Nessim Henein, Florent Cosandier, Hubert Pierre-Marie Benoît Schneegans

Mechanical watches are generally regulated by a balance and a spring constituting a harmonic oscillator. This mechanism is intrinsically force-balanced, which makes it essentially insensitive to gravity as well as to the linear accelerations of the watch. ...

Elsevier BV2025

Rectilinear Flexure-based Translation Stage Family with Minimized Parasitic Shift, High Support Stiffness and Large Range of Motion

Simon Nessim Henein, Florent Cosandier, Loïc Benoît Tissot-Daguette, Célestin Vallat

This article presents a novel family of exactly-rectilinear translation mechanisms, called the "QUADRISTAGE family", based on one-degree-of-freedom planar kinematics exclusively using pivot joints and rigid segments. Several variants are presented, some pr ...

Open Engineering Inc2025

Near-Zero Parasitic Shift Rectilinear Flexure Stages Based on Coupled n-RRR Planar Parallel Mechanisms

Simon Nessim Henein, Florent Cosandier

Flexure-based linear stages have become prevalent in precision engineering; however, most designs suffer from parasitic shifts that degrade positioning accuracy. Conventional solutions to mitigate these parasitic motions often compromise support stiffness, ...

MDPI AG2025

Zero-force rectilinear flexure-based translation stage: Experimental validations

Simon Nessim Henein, Florent Cosandier, Loïc Benoît Tissot-Daguette

Compliant mechanisms can advantageously be preloaded by buckled beams in order to reduce their motion stiffness, and therefore also their actuation forces. However, preloading compliant mechanisms has the side-effect of modifying the deformation of their f ...

2025

Residual stress chevron preloading amplifier for large-stroke stiffness reduction of silicon flexure mechanisms

Simon Nessim Henein, Florent Cosandier, Loïc Benoît Tissot-Daguette, Quentin Gubler

Residual stresses can be advantageously used to permanently preload flexure micro-mechanisms in order to modify their deflection and stiffness. This paper presents a new preloading chevron mechanism (PCM) used to amplify the preloading effect of thin film ...

IOP Publishing2025

Near-Zero Parasitic Shift Flexure Pivots Based on Coupled n-RRR Planar Parallel Mechanisms

Simon Nessim Henein, Florent Cosandier, Etienne Frédéric Gabriel Thalmann, Loïc Benoît Tissot-Daguette

Flexure pivots, which are widely used for precision mechanisms, generally have the drawback of presenting parasitic shifts accompanying their rotation. The known solutions for canceling these undesirable parasitic translations usually induce a loss in radi ...

2024

Design of a Flexure-Based Flywheel for the Storage of Angular Momentum and Kinetic Energy

Simon Nessim Henein, Florent Cosandier, Patrick Robert Flückiger, Hubert Pierre-Marie Benoît Schneegans

The flywheel is a widespread mechanical component used for the storage of kinetic energy and angular momentum. It typically consists of cylindrical inertia rotating about its axis on rolling bearings, which involves undesired friction, lubrication, and wea ...

2024

Mechanism balancing taxonomy

Simon Nessim Henein, Florent Cosandier, Hubert Pierre-Marie Benoît Schneegans

The balancing of mechanisms consists in distributing their moving masses, inertias, and elastic components in order to achieve key mechanical properties, such as the elimination of the shaking forces and moments exported onto their supporting structure or ...

2023

Zero Parasitic Shift Pivoting Kinematic Structures Based On Coupled N-RRR Planar Parallel Mechanisms For Flexure Pivot Design

Simon Nessim Henein, Florent Cosandier, Etienne Frédéric Gabriel Thalmann, Loïc Benoît Tissot-Daguette

Flexure pivots, which are widely used for precision mechanisms, generally have the drawback of presenting parasitic shifts accompanying their rotation. The known solutions for canceling these undesirable parasitic translations usually induce a loss in radi ...

ASME Amer Soc Mechanical Engineers2023

Damping of flexure blades based on bi-material additive manufacturing

Simon Nessim Henein, Florent Cosandier, Nicolas Blondiaux, Elias Sebastian Klauser, Loïc Benoît Tissot-Daguette, Nikola Kalentics, Lisa Salamin, Florent Alexandre Boudoire

Flexure-based mechanisms have become state-of-the-art solutions for the design of high-precision mechanisms, free from friction wear, backlash, and lubrication. These properties which are necessary for applications in ultraclean or harsh environments, neve ...

2023

Mechanism Balancing Taxonomy for the Classification of Horological Oscillators

Simon Nessim Henein, Florent Cosandier, Hubert Pierre-Marie Benoît Schneegans

The balancing of mechanisms consists in distributing their moving masses, inertias, and elastic components in order to achieve key mechanical properties, such as the insensitivity of the mechanism to gravity and to the motions of its chassis, or the elimin ...

2023

The isostatic 3-body problem: a complete solution

Simon Nessim Henein, François Barrot, Florent Cosandier, Johannes Richard Cornelis Geerit Kruis, Ilan Vardi

Kinematic couplings are used when two rigid bodies need to be repeatedly and accurately positioned with respect to each other. They allow for sub-micron positioning repeatability by suppressing play and reducing strains in the bodies. Typical applications ...

2017

6 DOF repeatability measurement setup for measuring position of assembled silicon parts with nanometric resolution

Simon Nessim Henein, François Barrot, Florent Cosandier, Johannes Richard Cornelis Geerit Kruis, Pascal Gentsch

This article presents a test setup dedicated to the measurement of the 6 degrees of freedom relative positioning assembly repeatability of three micro-manufactured parts equivalent to those composing a mesoscale flexure-based robot. The typical size of the ...

2015

Development and integration of high straightness flexure guiding mechanisms dedicated to the METAS watt balance Mark II

Reymond Clavel, Florent Cosandier

There is a firm will in the metrology community to redefine the kilogram in the International System of units by linking it to a fundamental physical constant. The watt balance is a promising way to link the mass unit to the Planck constant h. At the Feder ...

Iop Publishing Ltd2014

Design of the new METAS watt balance experiment Mark II

Reymond Clavel, Florent Cosandier

The kilogram is the last unit of the international system of units (SI) still based on a material artefact, the international prototype of the kilogram (IPK). The comparisons made in the last hundred years have clearly revealed a long-term relative drift b ...

Iop Publishing Ltd2013

Conception d'axes motorisés rectilignes d'ultra-haute précision

Florent Cosandier

EPFL2013