Publications de Lei Wang | EPFL Graph Search

Fault roughness controls injection-induced seismicity

Surface roughness ubiquitously prevails in natural faults across various length scales. Despite extensive studies highlighting the important role of fault geometry in the dynamics of tectonic earthquakes, whether and how fault roughness affects fluid-induc ...

National Academy of Sciences2024

Magnesium Test: Universal and Ultra-Sensitive Method for Measuring Reliability of Thin-Film-Encapsulated Bioelectronic Implants in Physiological Environment

Yves Leterrier, Stéphanie Lacour, Grégoire Courtine, Lei Wang, Ivan Furfaro, Claudia Kathe, Kangling Wu, Massimo Mariello

Next-generation bioelectronic implants require miniaturization, durability, and long-term functionality. Thin film encapsulations, prepared with inorganic or hybrid organic/inorganic designs, are essential for ensuring protection, low water permeation, ada ...

Wiley-V C H Verlag Gmbh2024

Ultra-tunable bistable structures for universal robotic applications

Jamie Paik, Ke Liu, Xin Tong, Lei Wang, Hongying Zhang, Yongkang Jiang

Bistable structures in nature are unparalleled for their fast response and force amplification even with the most minute physical stimula-tion. However, current works on bistable structures mainly focus on their stable states, while promising intermediate ...

CELL PRESS2023

Artificial Neural Network Approach to the Analytic Continuation Problem

Oleg Yazyev, Lei Wang, Quansheng Wu, Romain Fournier

Inverse problems are encountered in many domains of physics, with analytic continuation of the imaginary Green's function into the real frequency domain being a particularly important example. However, the analytic continuation problem is ill defined and c ...

AMER PHYSICAL SOC2020

Synthesis of Cyanine Polyelectrolytes and Anions for Organic Electronic Devices

Lei Wang

Many practical applications among organic electronic devices have been demonstrated over the last decades. They are considered as promising alternatives to inorganic semiconductor technologies due to the potential of cost-effective fabrication, excellent p ...

EPFL2017

Visible light-emitting host-guest electrochemical cells using cyanine dyes

Frank Nüesch, Beat Ruhstaller, Roland Hany, Lei Wang, Surendra Babu Anantharaman, Jakob Heier

Light-emitting electrochemical cells (LECs) can be fabricated as a single emissive organic/salt layer sandwiched between two electrodes, offering cost-effective next generation signage and lighting applications. Cyanine dyes are especially attractive to ex ...

Elsevier Science Bv2017

Phase Corrected H-Plane Horn Antenna in Gap SIW Technology

Juan Ramon Mosig, Marc Esquius Morote, Lei Wang

This communication introduces a modified substrate integrated waveguide (SIW), the gap SIW, and deduces an approximate closed-form expression for calculating its effective width, taking into account the fringing and coupling fields around the gap. As an im ...

Ieee-Inst Electrical Electronics Engineers Inc2017

Circularly Polarized Compact LTSA Array in SIW Technology

Juan Ramon Mosig, Marc Esquius Morote, Lei Wang

Typical linearly tapered slot antenna (LTSA) usually features a wideband and a high gain. However, its geometry size is large, especially very long in the tapering direction, which limits its application in compact antenna and array systems. This communica ...

Ieee-Inst Electrical Electronics Engineers Inc2017

Wideband Omnidirectional Planar Antenna with Vertical Polarization

Juan Ramon Mosig, Lei Wang

In this paper we propose a circular leaky wave-antenna with omnidirectional radiation in the H-plane. The design utilizes double-layered strips to create an end-fire antenna. A linear tapering of the stripes in the design endows the antenna with a 27% impe ...

Ieee2017

Wideband H-plane dielectric horn antenna

Juan Ramon Mosig, Maria Garcia Vigueras, Lei Wang, Marcos Alvarez Folgueiras

By flaring a dielectric waveguide in the H-plane, an H-plane dielectric horn is formed, which could be directly excited by an SIW feed. However, matching and radiation performances are poor due to the thinness of the substrate. To improve these performance ...

Inst Engineering Technology-Iet2017

Cyanine tandem and triple-junction solar cells

Frank Nüesch, Hui Zhang, Björn Niesen, Roland Hany, Lei Wang, René Uwe Schneider

Ultrathin bilayer heterojunction solar cells using cyanine electron donors and electron acceptor C-60 are used to fabricate monolithically stacked tandem and triple junction devices. Sub-cell stack sequences as well as C-60 layer thicknesses are optimized ...

Elsevier2016

Design of Compact Air-Vias-Perforated SIW Horn Antenna With Partially Detached Broad Walls

Lei Wang

A novel substrate-integrated waveguide (SIW) horn antenna with partially detached broad walls is designed and analyzed. The conventional SIW horn antenna suffers from narrow-operating bandwidth, which mainly results from the mismatch at the horn aperture b ...

Ieee-Inst Electrical Electronics Engineers Inc2016

Doping Evolution and Junction Formation in Stacked Cyanine Dye Light-Emitting Electrochemical Cells

Matia Bulloni, Beat Ruhstaller, Roland Hany, Lei Wang

Cyanine dyes are fluorescent organic salts with intrinsic conductivity for ionic and electronic charges. Recently (J. Am. Chem. Soc. 2013, 135, 18008-18011), these features have been exploited in cyanine light-emitting electrochemical cells (LECs). Here, w ...

Amer Chemical Soc2016

Compact Microstrip Feedings with an Elevated Ground Plane for Thick Folded SIW

Juan Ramon Mosig, Lei Wang, Qi Wu

Folded substrate integrated waveguide (FSIW) has been proposed for further size reduction, while keeping the advantages of traditional SIW. FSIW-based horn antennas are very promising in millimeter wave applications. To improve the bandwidth and efficiency ...

Ieee2016

Gain Enhanced H-plane Gap SIW Horn Antenna with Phase Correction

Juan Ramon Mosig, Marc Esquius Morote, Lei Wang

2015

Cyanine dye polyelectrolytes for organic bilayer solar cells

Hui Zhang, Roland Hany, Lei Wang

Polyelectrolytes composed of an anionic sulfoethyl methacrylate/methacrylate backbone and cationic cyanine dyes counter ions are synthesized. The effective reaction sequence is confirmed by NMR spectroscopy and consists of a thermal radical copolymerizatio ...

Elsevier Sci Ltd2014

Stability of bilayer trimethine cyanine dye/fullerene organic solar cells

Gaëtan Wicht, Hui Zhang, Roland Hany, Lei Wang

The long-term (up to 100 days) stabilities of thin films of a trimethine cyanine dye (Cy3-P) and of Cy3-P/C-60 bilayer solar cells with initial power conversion efficiencies of up to 3.6% in the regular and inverted device architecture were studied. For st ...

Elsevier Science Bv2013