Publications by Etienne Frédéric Gabriel Thalmann

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

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

Gravity-Compensation Design Approaches for Flexure-Pivot Time Bases

Simon Nessim Henein, Etienne Frédéric Gabriel Thalmann, Quentin Gubler

While flexure time bases have gained significant traction in the watchmaking industry thanks to their high quality factor and monolithic design, maintaining a stable frequency in varying orientations of wrist watches with respect to gravity remains a signi ...

MDPI2022

A load cell with adjustable stiffness and zero offset tuning dedicated to electrical micro- and nanoprobing

Simon Nessim Henein, Charles Baur, Etienne Frédéric Gabriel Thalmann, Loïc Benoît Tissot-Daguette, Michal Stanislaw Smreczak

The tasks of electrical micro- and nanoprobing require precision that goes beyond human perception and therefore, depend on sensors providing real-time feedback. Efforts towards automation in micro- and nanoprobing and emerging areas such as branched nanow ...

2022

Analytical modeling and experimental validation of rotationally actuated pinned–pinned and fixed–pinned buckled beam bistable mechanisms

Simon Nessim Henein, Etienne Frédéric Gabriel Thalmann, Loïc Benoît Tissot-Daguette, Hubert Pierre-Marie Benoît Schneegans

Buckled beams have become key building blocks in compliant mechanisms to achieve nonlinear behaviors, such as bistability, constant-force and stiffness tuning. However, designing and modeling such components is challenging due to their highly nonlinear cha ...

2022

Triple Crossed Flexure Pivot Based on a Zero Parasitic Center Shift Kinematic Design

Simon Nessim Henein, Etienne Frédéric Gabriel Thalmann

Thanks to their absence of play, absence of contact friction and possible monolithic fabrication, flexure pivots offer advantages over traditional bearings in small-scale, high accuracy applications and environments where lubrication and wear debris are pr ...

2022

Optical rotating torque sensor with nano newton-meter resolution based on a hanging torsion wire

Simon Nessim Henein, Billy Nussbaumer, Etienne Frédéric Gabriel Thalmann

This article presents a novel torque measuring setup working in the nano newton-meter range. The central novelty is a long (1 meter range) thin (diameter of a few tens of micrometers) metallic wire used instead of the relatively stiff torsion zone of the s ...

euspen2021

Shaking force balancing of a 2-DOF isotropic horological oscillator

Simon Nessim Henein, Etienne Frédéric Gabriel Thalmann, Hubert Pierre-Marie Benoît Schneegans

Despite centuries of research and significant advances, the escapement mechanism used to count and maintain oscillations of mechanical time bases remains a complex mechanism and a major source of energy losses. We showed in previous work that, instead of t ...

2021

Design of a Flexure Rotational Time Base with Varying Inertia

Simon Nessim Henein, Etienne Frédéric Gabriel Thalmann

Flexure oscillators are promising time bases thanks to their high quality factor and monolithic design compatible with microfabrication. In mechanical watchmaking, they could advantageously replace the traditional balance and hairspring oscillator, leading ...

2021

Design of a Triple Crossed Flexure Pivot With Minimized Parasitic Shift

Simon Nessim Henein, Etienne Frédéric Gabriel Thalmann

Thanks to their absence of play, absence of contact friction and possible monolithic fabrication, flexure pivots offer advantages over traditional bearings in small-scale, high accuracy applications and environments where lubrication and wear debris are pr ...

2021

Optical measurement method for mechanical time base characterization

Simon Nessim Henein, Etienne Frédéric Gabriel Thalmann

The recent adoption of silicon components by the mechanical watch industry has triggered the search for new time bases to advantageously replace the traditional balance and hairspring oscillator. In particular, flexure-based oscillators manufactured in sil ...

euspen2021

Flexure Pivot Oscillators for Mechanical Watches

Etienne Frédéric Gabriel Thalmann

It appears that the concerted efforts of the watchmaking industry are leading towards a limit in mechanical watch accuracy. The general consensus in horology is that the time base's quality factor, a dimensionless number that characterizes the oscillator d ...

EPFL2020

Flexure Pivot Oscillator With Intrinsically Tuned Isochronism

Simon Nessim Henein, Mohammad Hussein Kahrobaiyan, Etienne Frédéric Gabriel Thalmann, Ilan Vardi

The most important property for accurate mechanical time bases is isochronism: the independence of period from oscillation amplitude. This paper develops a new concept in isochronism adjustment for flexure-based watch oscillators. Flexure pivot oscillators ...

2020

Horological oscillator

Simon Nessim Henein, Billy Nussbaumer, Mohammad Hussein Kahrobaiyan, Etienne Frédéric Gabriel Thalmann, Ilan Vardi

Horological oscillator comprising: - a first inertial body (141; 151; 1305; 1405; 1505; 301; 311; 314; 41; 51; 507; 529; 544; 541; 901; 903) arranged to rotate with respect to a first axis; - a second inertial body (143; 153; 1306; 1406; 1506; 302; 313; 31 ...

2019

Conceptual design of a rotational mechanical time base with varying inertia

Simon Nessim Henein, Etienne Frédéric Gabriel Thalmann

Flexure pivot oscillators have the potential to advantageously replace the traditional balance wheel-spiral spring oscillator used in mechanical watches due to their significantly lower friction. However, they have inherent nonlinear elastic properties tha ...

2019

Flexure-Pivot Oscillator Restoring Torque Nonlinearity and Isochronism Defect

Simon Nessim Henein, Mohammad Hussein Kahrobaiyan, Etienne Frédéric Gabriel Thalmann

Flexure pivot based oscillators can advantageously replace the hairspring and balance wheel, the time base used in mechanical watches, by drastically reducing friction. However, flexure pivots have drawbacks including gravity sensitivity and restoring torq ...

AMER SOC MECHANICAL ENGINEERS2018

Echappements à impulsion virtuelle

Simon Nessim Henein, Roland Andreas Bitterli, Etienne Frédéric Gabriel Thalmann, Ilan Vardi, Laura Marie Lucie Convert

L’échappement à détente est reconnu pour sa performance chronométrique, mais il n’est pas sécurisé pour la montre-bracelet. Plusieurs échappements ont été proposés pour adapter cet échappement à la montre, dont l’échappement Robin récemment sécurisé par Au ...

2018

Gravity-Insensitive Flexure Pivot Oscillators

Simon Nessim Henein, Mohammad Hussein Kahrobaiyan, Etienne Frédéric Gabriel Thalmann, Ilan Vardi, Lennart Rubbert

Classical mechanical watch plain bearing pivots have frictional losses limiting the quality factor of the hairspring-balance wheel oscillator. Replacement by flexure pivots leads to a drastic reduction in friction and an order of magnitude increase in qual ...

2018

High Performance Control of a Corner Cube Reflector by a Frequency-Domain Data-Driven Robust Control Method

Alireza Karimi, Etienne Frédéric Gabriel Thalmann

The linear motion of the Corner Cube Mechanism developed for the infrared sounder of the third generations of Meteosat weather satellites requires a high level of accuracy. The system is subject to external micro-vibration perturbations from surrounding in ...

Ieee2016