Publications associées à Énergie mécanique

Synthesis of polysiloxane elastomers modified with sulfonyl side groups and their electromechanical response

Dielectric elastomer transducers are elastic capacitors that respond to mechanical or electrical stress. They can be used in applications such as millimeter-sized soft robots and harvesters of the energy contained in ocean waves. The dielectric component o ...

Royal Society of Chemistry2023

Computational design and additive manufacturing of electromagnetic coils

Adrien Jean-Michel Thabuis

The modern world is heavily reliant on electromagnetic devices to convert mechanical energy into electrical energy and vice versa. These devices are fundamental to powering our society, and the growing need for automated production lines and electrified tr ...

EPFL2023

High Permittivity Siloxanes as Promising Materials for Dielectric Elastomer Transducers: From Synthesis to Application

Yauhen Sheima

The speed of change in the modern world is impressive. Within the last 50 years, many devices and technologies have significantly transformed their appearance, intrinsic characteristics and improved their performance. Computers have changed from the size o ...

EPFL2022

Study of the enhanced electricity output of a sliding droplet-based triboelectric nanogenerator for droplet sensor design

Jürgen Brugger, Xia Liu, Wei Xu, Xiaopeng Li

Triboelectric nanogenerators are establishing themselves as promising candidates for realizing high-efficient energy harvesting from largely available droplets. However, the conventional droplet-based liquid-solid triboelectric nanogenerator (DLS-TENG) has ...

Elsevier2022

A High Efficiency Pneumatic Drive System Using Vane-Type Semi-Rotary Actuators

Alfred Rufer

A compressed air driven generator is proposed, where the pneumatic energy is converted into mechanical energy using two vane-type rotational actuators. The use of a second actuator with a higher displacement in order to produce a thermodynamic expansion al ...

UNIV NIS2021

Experimental Investigation of a Small-Scale Organic Rankine Cycle Turbo-Generator Supported on Gas-Lubricated Bearings

Jürg Alexander Schiffmann, Kévin Rosset

Waste heat recovery (WHR) is expected to contribute to reducing CO2 emissions from trucks. Organic Rankine cycle (ORC) systems show the highest potential for this application, but still lack efficient small-scale expansion devices, in practice. A novel tur ...

2021

Autonomous oil flow generated by self-oscillating polymer gels

Vito Cacucciolo

The previously reported gel and polymer actuators require external inputs, such as batteries, circuits, electronic circuits, etc., compared with autonomous motions produced by the living organisms. To realize the spontaneous motions, here, we propose to in ...

Nature Research2020

Variable Stiffness Spring Actuators for Low-Energy-Cost Human Augmentation

Salil Apte

Theoretical studies suggest and experimental evidence confirms that maintaining and changing human joint stiffness by coactivated antagonistic muscles are metabolically expensive, even if muscles do not perform net mechanical work. Based on this observatio ...

2019

Twist-Induced Snapping in a Bent Elastic Rod and Ribbon

Tomohiko Sano

Snapping of a slender structure is utilized in a wide range of natural and manmade systems, mostly to achieve rapid movement without relying on musclelike elements. Although several mechanisms for elastic energy storage and rapid release have been studied ...

2019

High voltage switch for compact bidirectional dc-dc converter driving dielectric electroactive polymer actuators

Yves Perriard, Yoan René Cyrille Civet, Morgan Almanza, Raphaël Johannes Charles Mottet, Lucas Pniak

Driving DEAs requires time-varying high voltage power supplies, up to 18kV for 200um polymer layers. HV amplifiers are commonly used but bulky and expensive. Designing embedded actuators requires compact and efficient powersupplies. Furthermore, only a lit ...

2019

Two-phase and oil-free co-rotating scroll compressor/expander

Jürg Alexander Schiffmann

This paper discusses experimental and theoretical investigations about a re-designed co-rotation scroll machine, operating in compressor and expander mode. The machine has been tested under various operational conditions, with the aim to determine the infl ...

2019

Electric Charge Transfer Between Cascading Dielectric Electroactive Polymer Actuators

Yves Perriard, Alexis Boegli, Jonathan André Jean-Marie Chavanne, Raphaël Johannes Charles Mottet

With the never slowing interest in dielectric electroactive polymer (DEAP) actuators for medical applications, the need to optimize the management of the driving energy of these actuators becomes evermore important. In order to tackle the problematic of th ...

2018

Electroadhesive device, system and method for gripping

Dario Floreano, Herbert Shea, Samuel Rosset, Jun Shintake, Bryan Edward Schubert

A device for electroadhesion and conversion of electrical energy into mechanical energy, for example electrostatic actuation, is provided, including a soft polymeric dielectric support having at least two sets of overlapping electrodes patterned respective ...

2017

Investigation of RF Nb-Ti PF 1&6 Coils Conductor Performances in the SULTAN Test Facility

Pierluigi Bruzzone, Boris Stepanov

This paper summarizes the work on the manufacturing and testing of conductor samples for ITER poloidal field 1&6 coils. The work was carried out by the IO and multiple institutions in the EU, Switzerland and Russia. Five samples were manufactured and teste ...

IEEE Institute of Electrical and Electronics Engineers2017

Advancing Materials and Methods for Photoelectrochemical Energy Conversion

Kevin Sivula

Strategies to convert energy from the sun into chemical fuels and feedstocks for a carbon-neutral economy are under rapid development. A photoelectrochemical route uses a direct semiconductor liquid junction that offers simplicity but places challenging co ...

Swiss Chemical Soc2017

Where Does Energy Go in Electron Energy Loss Spectroscopy of Nanostructures?

Jürgen Brugger, Olivier Martin, Duncan Thomas Lindsay Alexander, Jérémy Butet, Valentin Flauraud, Gabriel David Bernasconi

Electron energy loss spectroscopy is a method of choice for the characterization of both the spatial and spectral properties of localized surface plasmon resonances. The energy lost by the impinging electrons is commonly explained by the Lorentz force acti ...

2017

Coupling of electrocatalysts to photoabsorbers for solar fuels production

Carlos Gilberto Morales Guio

The direct transformation of sunlight into fuels and chemicals has attracted considerable attention for the potential impact on the storage of solar energies at large scales and the reduction of CO2 emissions. More than 80% of our current global energy con ...

EPFL2016

Mechanical work makes important contributions to surface chemistry at steps

William Curtin, Michael Frederick Francis

The effect of mechanical strain on the binding energy of adsorbates to late transition metals is believed to be entirely controlled by electronic factors, with tensile stress inducing stronger binding. Here we show, via computation, that mechanical strain ...

Nature Publishing Group2015

Interaction of a pulsating vortex rope with the local velocity field in a Francis turbine draft tube

François Avellan, Arthur Tristan Favrel, Christian Landry, Andres Müller, Matthieu Dreyer, Steven Roth, Alberto Bullani

Acoustic resonances in Francis turbines often define undesirable limitations to their operating ranges at high load. The knowledge of the mechanisms governing the onset and the sustenance of these instabilities in the swirling flow leaving the runner is es ...

IOP science2013

A study on the uplift mechanism of Tongjiezi dam using a coupled hydro-mechanical model

During filling in 1992 of the Tongiiezi reservoir, in Southwest China, it was noticed that the dam body and the rock masses on the right side of the valley were uplifted up to 22.2 mm and 24.3 mm respectively. After reservoir filling in 1993, the uplift co ...

2011