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Concept

Pyroélectricité

Publications associées (29)

Pyroelectricity in poled all-organic polar polynorbornene/polydimethylsiloxane-based stretchable electrets

Frank Nüesch, Francis Owusu

Pyroelectricity in a recently developed all-organic composite electret with a polar polynorbornene-based filler and polydimethylsiloxane (PDMS) matrix has been studied with the help of thermal and dielectric techniques. Measurement of the pyroelectric p co ...

Royal Society of Chemistry2024

Ferroelectric device or structure and a method for producing ferroelectric devices or structures

Tobias Kippenberg, Rui Ning Wang, Zelin Tan

The present invention concerns a method for producing at least one ferroelectric device or structure comprising the steps of providing at least one ferroelectric material or layer, or providing at least one ferroelectric material or layer to be patterned o ...

2023

Tailor-made Piezoelectric Elastomer Materials

Francis Owusu

Recent advancements in miniature devices with higher computational capabilities and ultralow power consumption have accelerated the development of wearable sensors, actuators, and energy harvesters everywhere. The ultimate aim of such a technological revol ...

EPFL2023

Domain Imaging and Switching Dynamics in BaTiO3-Based Photonic Integrated Devices

Jacqueline Geler Kremer

Keeping up with our constantly connected lifestyle of instant messages and video streaming has its repercussions. Data centers have been gobbling up resources becoming a significant share of the energy used worldwide. To keep up with demand and curb the en ...

EPFL2023

Printed degradable piezoelectric microsystems: From ink formulation to device fabrication and characterization

Morgan Mc Kay Monroe

As the world moves further and further into the semiconductor era, the amount of waste generated from electronics ("e-waste") is increasing rapidly and unsustainably. Of particular note, alternatives to lead-based piezoelectric materials must be establishe ...

EPFL2023

Field-induced ultrafast modulation of Rashba coupling at room temperature in ferroelectric alpha-GeTe(111)

Jan Hugo Dil

Rashba materials have appeared as an ideal playground for spin-to-charge conversion in prototype spintronics devices. Among them, alpha-GeTe(111) is a non-centrosymmetric ferroelectric semiconductor for which a strong spin-orbit interaction gives rise to g ...

Nature Portfolio2022

Stress effects on the impedance and ferroelectricity of PVDF-BiFeO3-MWCNT films using xanthan gum as dispersant

Frank Nüesch, Francis Owusu

Composite films based on dispersions of bismuth ferrite (BiFeO3) in polyvinylidene fluoride (PVDF) matrixes were prepared in the presence of multiwalled-carbon-nanotubes (MWCNT), using xanthan gum (XG) as dispersant. Films were prepared by spin coating and ...

ELSEVIER SCIENCE SA2022

Recent Advances in Piezoelectric Materials for Electromechanical Transducer Applications

Dragan Damjanovic

Ferroelectricity has made a huge impact on science and technology since Joseph Valasek (then a Ph.D. student at the University of Minnesota) discovered it in 1920, a little longer than 100 years ago. Whereas Dr. Valasek's original research was motivated by ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2022

Induced giant piezoelectricity in centrosymmetric oxides

Paul Muralt, Dragan Damjanovic, Vasiliki Tileli, Mahmoud Hadad, Lukas Riemer, Daesung Park

Piezoelectrics are materials that linearly deform in response to an applied electric field. As a fundamental prerequisite, piezoelectric materials must have a noncentrosymmetric crystal structure. For more than a century, this has remained a major obstacle ...

American Association for the Advancement of Science2022

Ferroelectric Effects Probed by in situ Transmission Electron Microscopy

Reinis Ignatans

Ferroelectric perovskite oxides are widely used in sensors, actuators and optical modulators and, at the same time, they show promise for implementation in future applications such as energy storage, memory and cooling devices. At the infancy of the discov ...

EPFL2022

Exploring negative capacitance and neuromorphic devices based on CMOS-compatible ferroelectric HfO2

Carlotta Gastaldi

Ferroelectric materials are explored for numerous applications thanks to their properties associated with electrically switchable spontaneous polarization. Perovskites are an established class of ferroelectrics used for sensors and actuators. However, they ...

EPFL2022

GaN-based power devices: Physics, reliability, and perspectives

Elison de Nazareth Matioli, Luca Nela, Riyaz Mohammed Abdul Khadar

Over the last decade, gallium nitride (GaN) has emerged as an excellent material for the fabrication of power devices. Among the semiconductors for which power devices are already available in the market, GaN has the widest energy gap, the largest critical ...

AIP Publishing2021

Piezo-electric and -phototronic effects of perovskite 2D|3D heterostructures

Mohammad Khaja Nazeeruddin, Hobeom Kim

Dimensionally-engineered perovskite heterostructures are highly attractive, as recently shown to be useful for enhancing the stability and efficiency in perovskite solar cells. Here, we first report piezo-electric and -phototronic effects found in two-dime ...

Elsevier2021

Actuation of piezoelectric structures with ferroelectric thin films having multiple elements

Paul Muralt

A method for driving piezoelectric elements of a micro-system. The piezoelectric elements comprising a ferroelectric thin film, and being configured to be part of any one or a combination of items of a list comprising: a cantilever, a bridge, a diaphragm, ...

2020

Time-resolved open-circuit conductive atomic force microscopy for direct electromechanical characterisation

Anna Fontcuberta i Morral, Wonjong Kim, Jelena Vukajlovic Plestina

Studying nanomaterial piezoelectricity and triboelectricity is attractive for energy and sensing applications. However, quantitative characterisation of electromechanical effects in nanomaterials is challenging due to practical limitations and possible com ...

2020

Functional and Responsive Polymers via Controlled Radical Polymerization

Jian Wang

This Thesis is built around 4 topics, which share in common that they all take advantage of the assets of controlled radical polymerization to either (i) prepare well-defined model systems to address fundamental research questions with regard to the sensit ...

EPFL2020

Determination of the internal piezoelectric potentials and indium concentration in InGaN based quantum wells grown on relaxed InGaN pseudo-substrates by off-axis electron holography

Victor Carle Adrien Boureau

Micro light emitting diodes have been grown by metal organic vapor phase epitaxy on standard GaN and partly relaxed InGaNOS substrates with the purpose of incorporating higher concentrations of indium for identical growth conditions. Green emission has bee ...

2020

Nanowire Tunnel FET with Simultaneously Reduced Subthermionic Subthreshold Swing and Off-Current due to Negative Capacitance and Voltage Pinning Effects

Mihai Adrian Ionescu, Igor Stolichnov, Ali Saeidi, Matteo Cavalieri, Teodor Rosca

Nanowire tunnel field-effect transistors (TFETs) have been proposed as the most advanced one-dimensional (1D) devices that break the thermionic 60 mV/decade of the subthreshold swing (SS) of metal oxide semiconductor field-effect transistors (MOSFETs) by u ...

AMER CHEMICAL SOC2020

Moire Flat Bands in Twisted Double Bilayer Graphene

Oleg Yazyev, Quansheng Wu, Seyedeh Fatemeh Haddadi Givi

We investigate twisted double bilayer graphene (TDBG), a four-layer system composed of two AB-stacked graphene bilayers rotated with respect to each other by a small angle. Our ab initio band structure calculations reveal a considerable energy gap at the c ...

AMER CHEMICAL SOC2020

Dielectric Actuation Techniques at the Nanoscale: Piezoelectricity and Flexoelectricity

Kaitlin Marie Howell

Micro- and nanoelectromechanical systems (MEMS/NEMS) have long shown their potential to disrupt the established technologies. Over the past 15 years, MEMS have become fundamental components in filters, accelerometers, gyroscopes and gas sensors. MEMS are n ...

EPFL2019