Publications de Simon Nessim Henein

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

Barefoot Academic Teaching, Performing Arts as a pedagogical tool in Higher Education

Simon Nessim Henein, Ramiro Tau

This book delves into essential, yet often overlooked, aspects of educational and scientifi c practices: the involvement of the body in knowledge acquisition and production, the collective nature of creativity, and the potent role of improvisation in all l ...

Schibri-Verlag2024

Shape memory alloy mechanical actuator with reduced commutation time

Simon Nessim Henein, Charles Baur, Loïc Benoît Tissot-Daguette, Marjan Ghorbani

Using shape memory alloys (SMAs) as actuators offers several advantages, including high power density, large stroke capabilities, and friction elimination. These attributes make SMAs suitable for actuating flexure-based mechanisms in a wide array of extrem ...

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

Pivot, process for manufacturing such a pivot, oscillator comprising such a pivot, watch movement and timepiece comprising such an oscillator

Simon Nessim Henein, Loïc Benoît Tissot-Daguette

The present invention concerns a pivot comprising two assemblies, namely a central assembly (401) and a peripheral assembly (400). These two assemblies are mobile in rotation relative to each other around an axis of rotation (A). The pivot is characterized ...

2024

Dissonant Geometries

Simon Nessim Henein, Joëlle Valterio, Julien Lafontaine Carboni, Tiphaine Laure Elodie Abenia

Lars Müller Publishers2024

Exploring the impact and challenges of an embodied and improvisation-based couse: insights from engineering students

Simon Nessim Henein

This study employs thematic analysis to delve into the experiences of 12 alumni engineering students who participated in the elective course "Collective Creation: Improvised Arts and Engineering" at the Swiss Federal Institute of Technology of Lausanne (EP ...

European Society for Engineering Education (SEFI)2024

Fully compliant snap-through bistable gripper mechanism based on a pinned-pinned buckled beam

Simon Nessim Henein, Charles Baur, Loïc Benoît Tissot-Daguette

This paper presents a new planar flexure-based bistable two-jaw parallel gripper mechanism. The bistability of the mechanism is enabled by a pinned-pinned buckled beam suspended onto two cross-spring pivots. External energy is required only during the swit ...

2024

High-precision flexure-based XY-stage with high stiffness and load capacity

Simon Nessim Henein, Charles Baur, Patrick Robert Flückiger, Hubert Pierre-Marie Benoît Schneegans

Typical flexure-based XY-stages have a serial design, and their layout results in the flexures being loaded in flection in face of heavy payloads or vertical loads. This paper presents a design with zero parasitic shift in which all flexures are loaded in ...

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

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