Recherche

Afficher tous les résultats pour

Accueil

Personne

Luis Guillermo Villanueva Torrijo

À propos
Confidentialité
Mentions légales

Graph Chatbot

Publications associées (132)

Optimum ratio of hydrophobic to hydrophilic areas of biphilic surfaces in thermal fluid systems involving boiling

Luis Guillermo Villanueva Torrijo, Tom Larsen, Ahmad Reza Motezakker

Pool boiling has a high heat removal capability and is considered as one of the most effective cooling methods due to utilization of latent heat of vaporization. Surface wettability plays a key role in boiling heat transfer since it controls the contact li ...

2019

5 GHz Band n79 wideband microacoustic filter using thin lithium niobate membrane

Victor Plessky, Luis Guillermo Villanueva Torrijo, Soumya Yandrapalli, Bruno Garcia

Microacoustic resonators made on suspended continuous membranes of LiNbO3 were recently shown to have very strong coupling and low losses at >= 5 GHz, suitable for high-performance filter design. Employing these simple resonator structures, the authors hav ...

2019

Phase Noise Measurements Of Aluminum Scandium Nitride Oscillators

Luis Guillermo Villanueva Torrijo, Andrea Lozzi, Marco Liffredo

This paper presents the first phase noise (PN) measurements of oscillators based on aluminum scandium nitride (AlScN) resonators. 2-port AlScN contour mode resonators (CMR) operating at 195 MHz arc fabricated. A large pool of Q values (ranging from 150 to ...

IEEE2019

Al0.83Sc0.17N Contour-Mode Resonators With Electromechanical Coupling in Excess of 4.5%

Paul Muralt, Luis Guillermo Villanueva Torrijo, Andrea Lozzi

In this paper, we demonstrate the fabrication of contour-mode resonators (CMRs) with Al0.83Sc0.17N as a piezoelectric layer. Moreover, we assess the electromechanical coupling and the maximum achieved quality factor from 150 to 500 MHz. In comparison to pu ...

2019

Effect of AlN seed layer on crystallographic characterization of piezoelectric AlN

Paul Muralt, Luis Guillermo Villanueva Torrijo, Ramin Matloub Aghdam, Waqas Bashir, Annalisa De Pastina, Kaitlin Marie Howell

Ultrathin aluminum nitride (AlN) films are of great interest for integration into nanoelectromechanical systems for actuation and sensing. Given the direct relationship between crystallographic texture and piezoelectric (PZE) response, x-ray diffraction ha ...

2019

On "Cavitation on Chip" in Microfluidic Devices With Surface and Sidewall Roughness Elements

Luis Guillermo Villanueva Torrijo, Morteza Ghorbani, Ahmad Reza Motezakker

In this paper, cavitating flows are characterized in 29 microfluidic devices in order to achieve a comprehensive perspective regarding flow patterns in microscale, which is crucial in the applications, such as energy harvesting and biomedical treatment. Wh ...

Institute of Electrical and Electronics Engineers2019

Analysis of XBAR resonance and higher order spurious modes

Victor Plessky, Luis Guillermo Villanueva Torrijo, Soumya Yandrapalli

A suspended 400nm thin mono-crystalline ZY cut Lithium Niobate (LN) membrane with narrow interdigital electrodes (IDEs) on top having a pitch of the order of few microns excites standing shear bulk acoustic wave resonance (XBAR) within the membrane through ...

IEEE2019

Shape memory polymer resonators as highly sensitive uncooled infrared detectors

Herbert Shea, Luis Guillermo Villanueva Torrijo, Juan José Zarate, Tom Larsen, Ulas Adiyan

Uncooled infrared detectors have enabled the rapid growth of thermal imaging applications. These detectors are predominantly bolometers, reading out a pixel’s temperature change due to infrared radiation as a resistance change. Another uncooled sensing met ...

Nature Research2019

Engineered Lateral Roughness Element Implementation and Working Fluid Alteration to Intensify Hydrodynamic Cavitating Flows on a Chip for Energy Harvesting

Luis Guillermo Villanueva Torrijo, Morteza Ghorbani

Hydrodynamic cavitation is considered an effective tool to be used in different applications, such as surface cleaning, ones in the food industry, energy harvesting, water treatment, biomedical applications, and heat transfer enhancement. Thus, both charac ...

2019

Fabrication Of Lithium Niobate Bulk Acoustic Resonator For 5G Filters

Victor Plessky, Luis Guillermo Villanueva Torrijo, Annalisa De Pastina, Soumya Yandrapalli, Muhammad Faizan

This work presents the fabrication of a MEMS resonant device which addresses the need for high quality and miniaturized RF filters in the 3-6 GHz range for 5th generation (5G) mobile networks. The 4-mask fabrication process is based on the definition of in ...

IEEE2019

Fabrication of suspended microchannel resonators with integrated piezoelectric transduction

Luis Guillermo Villanueva Torrijo, Damien Maillard, Annalisa De Pastina

2018

Hydrodynamic cavitation in microfluidic devices with roughened surfaces

Luis Guillermo Villanueva Torrijo, Morteza Ghorbani

2018

Observation of a phononic quadrupole topological insulator

Luis Guillermo Villanueva Torrijo, Tom Larsen

2018

Effective quality factor tuning mechanisms in micromechanical resonators

Luis Guillermo Villanueva Torrijo, Azadeh Ansari

Quality factor (Q) is an important property of micro- and nano-electromechanical (MEM/NEM) resonators that underlie timing references, frequency sources, atomic force microscopes, gyroscopes, and mass sensors. Various methods have been utilized to tune the ...

2018

Intensifying cavitating flows in microfluidic devices with poly(vinyl alcohol) (PVA) microbubbles

Luis Guillermo Villanueva Torrijo, Morteza Ghorbani

Cavitation and the energy associated with the collapse of resulting cavitation bubbles constitute an important research subject. The collapse of the hydrodynamic cavitation bubbles at the outlet of the flow elements leads to a high energy release and gener ...

2018

Energy Harvesting in Microscale with Cavitating Flows

Yusuf Leblebici, Luis Guillermo Villanueva Torrijo, Morteza Ghorbani, Ahmad Reza Motezakker, Ali Mohammadi

Energy harvesting from thermal energy has been widely exploited to achieve energy savings and clean technologies. In this research, a new cost-effective and environment-friendly solution is proposed for the growing individual energy needs thanks to the ene ...

Amer Chemical Soc2017

Three-Dimensional Nano-Acoustic Bragg Reflectors for CMOS Embedded NEMS

David Ruffieux, Luis Guillermo Villanueva Torrijo, Soumya Yandrapalli

Integration of CMOS electronic circuits and electromechanical resonators has been pursued for a long time by many different research groups and even foundries. This would improve the overall performance of electromechanical oscillators and sensors. However ...

Institute of Electrical and Electronics Engineers2017

Asymmetrically coupled resonators for mass sensing

Luis Guillermo Villanueva Torrijo

Mechanically coupled resonators have been applied in the last years to the development of nanomechanical mass-sensors based on the detection of the different vibration modes of the system by measuring on a single resonator. Their sensitivity and capability ...

American Institute of Physics2017

Release area confinement in Contour Mode Resonators

Luis Guillermo Villanueva Torrijo, Annalisa De Pastina, Andrea Lozzi

In this paper we propose a modified fabrication process to finely define the region surrounding the resonator that undergoes Si etching in CMRs. The unpredictable undercut has been shown to lead to Q instability within microns' variation. High aspect ratio ...

Ieee2017

Position and mode dependent optical detection back-action in cantilever beam resonators

Luis Guillermo Villanueva Torrijo, Tom Larsen

Optical detection back-action in cantilever resonant or static detection presents a challenge when striving for state-of-the-art performance. The origin and possible routes for minimizing optical back-action have received little attention in literature. He ...

Institute of Physics2017

Page 4 sur 7