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Luis Guillermo Villanueva Torrijo

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Related publications (129)

Page 2 of 7

Shape memory polymer resonators as highly sensitive uncooled infrared detectors

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

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

Stenciled conducting bismuth nanowires

Jürgen Brugger, Luis Guillermo Villanueva Torrijo, Andreea Veronica Savu, Oscar Vazquez Mena, Katrin Sidler Arnet, Sam Neuser

Stencil lithography is used here for the fabrication of bismuth nanowires using thermal evaporation. This technique provides good electrical contact resistance by having the nanowire structure and the contact pads deposited at the same time. It has also th ...

2010

Effect of AlN seed layer on crystallographic characterization of piezoelectric AlN

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

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

Analysis of the blurring in stencil lithography

Jürgen Brugger, Luis Guillermo Villanueva Torrijo, Andreea Veronica Savu, Oscar Vazquez Mena, Katrin Sidler Arnet, Philippe Langlet

A quantitative analysis of the blurring and its dependence on the stencil-substrate gap and the deposition parameters in stencil lithography, a high resolution shadow mask technique, is presented. The blurring is manifested in two ways: first, the structur ...

2009

Suspended lithium niobate acoustic resonators with Damascene electrodes for radiofrequency filtering

Luis Guillermo Villanueva Torrijo, Silvan Stettler

Data rates and volume for mobile communication are ever-increasing with the growing number of users and connected devices. With the deployment of 5G and 6G on the horizon, wireless communication is advancing to higher frequencies and larger bandwidths enab ...

Springer Science and Business Media LLC2025

On the effect of linear feedback and parametric pumping on a resonator's frequency stability

Zohreh Mohammadi, Luis Guillermo Villanueva Torrijo

Resonant sensors based on micro- and nano-electro mechanical systems (M/NEMS) are ubiquitous in many sensing applications due to their outstanding performance capabilities, which are directly proportional to the quality factor (Q) of the devices. We addres ...

2020

Resistless nanofabrication by stencil lithography: A review

Jürgen Brugger, Luis Guillermo Villanueva Torrijo, Oscar Vazquez Mena

We present a review on stencil lithography and focus on the particular interest and challenges when applying it to the scalable fabrication of nm-size devices. We first describe the basic technique with its main advantages and challenges. Then we review th ...

Elsevier2015

18 GHz Ultraviolet Astrocomb via Chip-Integrated Harmonic Generation

Luis Guillermo Villanueva Torrijo, Furkan Ayhan

Current machine learning models for vision are often highly specialized and limited to a single modality and task. In contrast, recent large language models exhibit a wide range of capabilities, hinting at a possibility for similarly versatile models in co ...

Optical Society of America2023

The transition in hydrogen sensing behavior in non-continuous palladium films

Jürgen Brugger, Luis Guillermo Villanueva Torrijo, Thomas Kiefer

The morphological transition in ultrathin palladium (Pd) films around the percolation threshold and the related transition in hydrogen sensing behavior is investigated.We find that besides the transition from continuous to discontinuous Pd, an intermediate ...

American Institute of Physics2010

Fabrication of clamped-clamped beam resonators with embedded fluidic nanochannel

Davide Scaiola, Philippe Renaud, Luis Guillermo Villanueva Torrijo, Annalisa De Pastina, Damien Maillard, Stefano Silvio Giovanni Varricchio

Suspended nanochannel resonators (SNRs) are promising devices able to characterize mass down to the attogram scale, thus being able to detect nanoparticles or biomolecules. In this paper, we present a flexible fabrication process for SNRs based on a sacrif ...

ELSEVIER2020

Energy Harvesting in Microscale with Cavitating Flows

Luis Guillermo Villanueva Torrijo, Yusuf Leblebici

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

Simulating supercontinua from mixed and cascaded nonlinearities

Luis Guillermo Villanueva Torrijo, Victor Brasch, Tobias Herr, Furkan Ayhan, Thibault Voumard

Nonlinear optical frequency conversion is of fundamental importance in photonics and underpins countless of its applications: Sum- and difference-frequency generation in media with quadratic nonlinearity permits reaching otherwise inaccessible wavelength r ...

AIP Publishing2023

Resistivity Measurements of Gold Wires Fabricated by Stencil Lithography on Flexible Polymer Substrates

Jürgen Brugger, Luis Guillermo Villanueva Torrijo, Andreea Veronica Savu, Oscar Vazquez Mena, Marc Antonius Friedrich van den Boogaart, Katrin Sidler Arnet

We report on the patterning and characterization of titanium–gold (Ti–Au) wire test structures on polyethylene naphthalate (PEN), polyethylene terephthalate (PET) and polyimide (PI) substrates. PEN, PET and PI are flexible polymers which can withstand stre ...

Elsevier2008

Directed Self-Assembly of Block Copolymers for the Fabrication of Functional Devices

Luis Guillermo Villanueva Torrijo

Directed self-assembly of block copolymers is a bottom-up approach to nanofabrication that has attracted high interest in recent years due to its inherent simplicity, high throughput, low cost and potential for sub-10 nm resolution. In this paper, we revie ...

MDPI2020

Periodic Structure of Narrow FBARs Operating on SH1 Mode in LN Membrane Solidly Mounted on SiC Substrate

Luis Guillermo Villanueva Torrijo, Seniz Esra Küçük, Nan Xu

We propose a system of narrow FBARs with alternating voltage polarity on top electrodes on the LN platelet and a common bottom floating electrode positioned on a substrate with high acoustic velocity (SiC). This is a YBAR device that is attached to a SiC s ...

Institute of Electrical and Electronics Engineers Inc.2024

Flexoelectricity in amorphous hafnium oxide (HfO2)

Luis Guillermo Villanueva Torrijo, Kaitlin Marie Howell, Daniel Moreno Garcia

Flexoelectricity, inherent in all materials, offers a promising alternative to piezoelectricity for nanoscale actuation and sensing. However, its widespread application faces significant challenges: differentiating flexoelectric effects from those of piezo ...

2024

Frequency fluctuations in nanomechanical silicon nitride string resonators

Luis Guillermo Villanueva Torrijo

High quality factor (Q) nanomechanical resonators have received a lot of attention for sensor applications with unprecedented sensitivity. Despite the large interest, few investigations into the frequency stability of high-Q resonators have been reported. ...

AMER PHYSICAL SOC2020

Sub-100 nm-scale Aluminum Nanowires by Stencil Lithography: Fabrication and Characterization

Jürgen Brugger, Luis Guillermo Villanueva Torrijo, Andreea Veronica Savu, Oscar Vazquez Mena, Marc Antonius Friedrich van den Boogaart, Katrin Sidler Arnet

We present the fabrication process and electrical characterization of sub-100 nm scale Al nanowires (NWs) fabricated by stencil lithography (SL). We use a stencil with sub- 100 nm wide nanoslits patterned by focused ion beam (FIB) milling. The stencil is a ...

2008

FABRICATION AND ANALYSIS OF THIN FILM LITHUM NIOBATE RESONATORS FOR 5GHz FREQUENCY AND LARGE k(t)(2) APPLICATIONS

Luis Guillermo Villanueva Torrijo, Soumya Yandrapalli, Seniz Esra Küçük

This work presents the fabrication and analysis of suspended thin film Lithium Niobate resonators. The yield of the new fabrication process presented below is >90% showing devices with high k(t)(2) of 28% resonators at 5GHz, making them suitable for high f ...

IEEE2021

Pd-functionalized MEMS resonator for hydrogen gas sensing at ambient pressure

Jürgen Brugger, Luis Guillermo Villanueva Torrijo, Thomas Kiefer, Jonas Gustav Henriksson

This work presents the fabrication and characterization of a novel hydrogen-detecting micro-resonator based on the expansion of palladium (Pd) as it is exposed to hydrogen (H2) gas. The working principle of the device has been confirmed and it shows a stro ...

2010