Publications associées à Montre électrique

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, Ilan Vardi, Etienne Frédéric Gabriel Thalmann, Mohammad Hussein Kahrobaiyan

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

Tribological Approach to the Watch Movements

Valentine Agnès Madeleine Magnin

Mechanical watches are complex and sensitive systems that have to maintain a faultless precision over their lifetime. However, this precision can be altered by disturbances occurring during the functioning time, such as friction, lubricant drying, or wear, ...

EPFL2020

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

MEMS Generator Study for an Embedded Energy Harvesting System

Jasha Poliakine

This work has been triggered by an industrial project targeting the development of a novel regulation system for a mechanical watch. Mechanical watches have been known for over a century as one of the finest example of energy autonomous devices, embodying ...

EPFL2018

Programmable Multistable Mechanisms: Design, modeling, characterization and applications

Mohamed Gamal Abdelrahman Ahmed Zanaty

Multistable Mechanisms are mechanical devices having more than one stable state. Since these mechanisms can maintain different deformations with zero force, they are advantageous for low power environments such as wristwatches and medical devices. In this ...

EPFL2018

Long-life plastic optical fiber probes for scanning near-field optical microscope

Giovanni Dietler, Serguei Sekatski, Anton Smirnov, Ekaterina Rostova

Nowadays, sharpened glass fiber - made probes attached to a quartz tuning fork (TF) and exploiting the shear force - based feedback are by far the most popular in the field of SNOM. These probes are expensive, very fragile and their fabrication is difficul ...

SPIE-INT SOC OPTICAL ENGINEERING2018

Flexure-Pivot Oscillator Restoring Torque Nonlinearity and Isochronism Defect

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

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

Recent improvements on micro-thermocouple based SThM

Danick Briand

The scanning thermal microscope (SThM) has become a versatile tool for local surface temperature mapping or measuring thermal properties of solid materials. In this article, we present recent improvements in a SThM system, based on a micro-wire thermocoupl ...

Iop Publishing Ltd2017

Colossal electroresistance and colossal magnetoresistance in spinel multiferroic CdCr2S4

Helmuth Berger

Colossal magnetoresistance (CMR) and colossal electroresistance (CER) induced by the electric field in spinel multiferroic CdCr2S4 are reported. It is found that a metal-insulator transition in CdCr2S4 is triggered by the electrical field. In magnetic fiel ...

AIP American Institute of Physics2010

A simple and accurate method for calibrating the oscillation amplitude of tuning-fork based AFM sensors

Majed Chergui, Jinquan Liu, Andrea Callegari

We have developed a simple and accurate method for calibrating the amplitude of vibration of quartz tuning fork sensors commonly used in at. force- and near field optical-microscopy. Unlike interferometric methods, which require a complex optical setup, th ...

2008

Analysis and modeling of electrostatic discharge in a tactile glass featured watch

Yves Perriard, Paolo Germano, Lionel Paratte, Daniele Demarco

Electrostatic discharge in quartz watches is becoming more and more important due to the use of plastic materials and tactile sensors. The discharge can lead to different type of dysfunction such as a simple reset, a latch-up, or the destruction of the ele ...

2007

Conception et optimisation multicritère des échappements libres pour montres-bracelets mécaniques

Thierry Conus

The watchmaking crisis of the nineteen-seventies in effect marked an interruption of scientific research into the working of mechanical watches. For the past few years, a revival of interest in these timepieces has given industrialists the financial resour ...

EPFL2007

Q-factor optimization of a tuning-fork/fiber sensor for shear-force detection

Majed Chergui, Jinquan Liu, Andrea Callegari

We present the results of an exptl. and theor. study on the optimum design of shear-force sensors, used in scanning probe microscopes. We have optimized a configuration consisting of a tuning-fork/fiber-tip assembly, achieving quality factors (Q) exceeding ...

AIP American Institute of Physics2005