Optomechanical resonator sensors for biological applications.

Speaker: Dr. Eduardo Gil Santos.
Organization: Instituto de Micro y Nano Tecnología-CSIC-Instituto de Sistemas Optoelectrónicos y Microtecnología (ISOM), Universidad Politécnica de Madrid.

Data: July 22nd, 2022.
Hours: 10.00 hours.
Place: Room B-222 of the ETSI of Telecommunications of the UPM [Cómo llegar]

ABSTRACT

In the last decades, optomechanical resonators have been the subject of extensive research in a variety of fields, such as communication, signal processing, novel quantum technologies and advanced sensing. This talk focuses on the recent advances performed in the optomechanics field regarding their application as biological sensors. In particular, I will show the different optomechanical devices we have developed in the BioNanoMechanics Laboratory: nanowires, nanodisks and microcapillaries. Each of these devices are specifically designed for detecting, characterizing and identifying particular bioentities, mainly depending on their sizes. While microcapillars are ideally suited for human cells applications, nanodisks can applied for bacteria and virus, and nanowires for proteins.  In the near future, optomechanical devices may provide many different applications in the clinical diagnosis and biomedicine fields. Among them, it is worthy to highlight the prompt diagnosis of infectious diseases and cancer, as well as the development of novel drugs, such as, antibiotics.

Brief resume of Eduardo Gil Santos´ Curriculum Vitae

duardo Gil Santos graduated in Physics in 2007 (USC). He joined the Bionanomechanics Laboratory (CSIC) in October 2007 through a national competitive grant (JAE Predoc). He obtained his PhD in Physics in May 2012. At that time, he worked on the development of novel devices, concepts and techniques in order to improve the capabilities of micro- and nano-mechanical sensors, always looking for biological and biomedicine applications.

In February 2013, he joined the Materials and Quantum Phenomena Laboratory (Paris Diderot University, France) thanks to an international competitive grant (Research in Paris). During this time, he learnt theoretical and experimental aspects about optomechanical devices and their applications. He opened a new research line focused on the development of optomechanical resonators for sensing applications.

In November 2016, he came back to the Bionanomechanics Laboratory by means of a European grant (Marie Sklodowska-Curie Actions, Individual Fellowship) with the goal of applying optomechanical devices as biological sensors. Currently, he is a “Ramón y Cajal” researcher working at the Bionanomechanics Laboratory.

In the last years, he has obtained six national project as principal investigator (ComFuturo, RETOS, “Ramón y Cajal”, “Intramural Especial”, “Fundación Ramón Areces” and “Leonardo”) which has enabled him to consolidate his own research line. His main research objective is to develop optomechanical devices as biological sensors, definitively bringing them to the society. Apart from his own projects, he is involved in several European projects (ERC-CoG and FET-proAct, among others).

His scientific work has been published in 1 book chapter, 30 ISI-indexed articles and 4 patents (1 licensed, 2 granted and 1 registered). This work has received 831 citations (WoS), with an h-index of 16 (WoS).

Special double session: Optical characterization of doped GaN nanowires for their use as single photon emitters/ Red to Blue Wavelength-Tunable Light Emitting Diode.

Speakers: Jovana Obradovic,Mikolaj Zak, PhD students.
Organization: Instituto de Sistemas Optoelectrónicos y Microtecnología (ISOM), E.T.S.I. Telecomunicación, Universidad Politécnica de Madrid.

Data: June 24th, 2022.
Hours: 10.00 hours.
Place: Room B-222 of the ETSI of Telecommunications of the UPM [Cómo llegar]

ABSTRACT

Optical characterization of doped GaN nanowires for their use as single photon emitters

One of the current challenges in Quantum Cryptography is development of an efficient quantum light emitter (single photon source) that can work in a wide spectral range. Works until this day show that InGaN/GaN nanowires are good candidates for being a single photon source in optical circuits. For making them possible to work while exciting them electrically, it is necessary to dope them with materials such as Si and Mg. This work is mainly about the study of destruction of the crystal structure while p-doping and n-doping of the nanowires.

Red to Blue Wavelength-Tunable Light Emitting Diode

InGaN-based light emitting diodes (LEDs) remain under intensive investigation due to its applications in display technology. By tuning InGaN composition its energy gap can cover the entire visible light spectrum. It was also shown that it is possible to achieve tunable red, green and blue emission from single device. For this approach, authors used active region consisted of three sets of quantum wells (QWs) with various indium contents with every set separated by specially designed intermediate carrier blocking layer. This design of active region allowed authors to control the carrier injection process and resulted in the red, green and blue emission appearing under low, average and high forward currents, respectively. For dominant blue emission, however, still green and red tail remained in the spectra.

In this work we show an alternative way to obtain the fully tunable, single peak light emission in wide range of wavelength from 650 nm (red) to 480 nm (blue). Our novel design of Wavelength-Tunable Light Emitting Diode (WT LED) is based on single QW with moderate 17% indium content. To realize the emission tunability we rely on doping engineering of the active region. The 15.6 nm wide QW is heavily doped, bottom half with n-type and top half with p-type. The surrounding barriers are also doped, but at the times lower. The WT LED structure was grown by Plasma-assisted Molecular Beam Epitaxy (PAMBE). As the current density increases from 0.2 A/cm2 to 400 A/cm2, the spectrum smoothly shifts from 650 nm to 480 nm.
In the WT LED active region there is a strong interaction between the built-in polarization and electric field caused by the heavy doping. As a result the valence and conduction bands bend inside the InGaN QW in such a way that two additional separate potential minima for electrons and holes are formed. This results in decreasing the energy difference between electrons and holes ground states under small forward voltage. The wave functions are spatially separated, but there is small overlap leading to red emission. By increasing the voltage, the ground states energy difference increases, which shifts the spectra to shorter wavelengths, up to finally blue emission typical for 17% InGaN QW.
 

Interdigitated Back Contact – Thermophtovoltaic cells of germanium based on pulse laser melting.

Speaker: Álvaro Medrano, a PhD student.
Organization: Instituto de Energía Solar (IES), a E.T.S.I. Telecomunicación, Universidad Politécnica de Madrid.

Data: June 17th, 2022.
Hours: 10.00 hours.
Place: Room B-222 of the ETSI of Telecommunications of the UPM [Cómo llegar]

ABSTRACT

Thermophotovoltaics (TPV) has been developed for thermal-to-electric energy conversion in a wide range of applications, including combined heat and power, thermal energy storage, or waste-heat recovery. The main difference with conventional photovoltaics is the source of light, instead of using the sun (solar-PV), the source will be an incandescent body (Thermo-PV) at medium temperature (800-2000ºC). 
In this work, germanium-based thermophotovoltaic cells are being developed to be used as highly efficient energy harvesting systems for heat sources in the order of 1000ºC. With this objective, an interdigitated back contact architecture is being developed to obtain higher efficiency by avoiding the shadowing of the device generated with the front contacts. Also, the manufacturing process is done with an ultraviolet laser to simplify the process and skip steps such as photolithography. 
The final objective is to integrate this cell into thermal batteries for the conversion of the light emitted by an incandescent body into electrical energy. 

Transparent electrodes in the IR based on transition metal dichalcogenides

Speaker: Dr. Juan Luis García Pomar.
Organization: Instituto de Sistemas Optoelectrónicos y Microtecnología (ISOM), de la E.T.S.I. Telecomunicación, Universidad Politécnica de Madrid.

Data: June 3rd, 2022.
Hours: 10.00 hours.
Place: Room B-222 of the ETSI of Telecommunications of the UPM [Cómo llegar]

ABSTRACT

Two dimensional materials have emerged as a toolbox for the fields of nanophotonics and nano-optoelectronics, providing new properties that are not possible to find in conventional materials. In particular, semiconductor transition metal dichalcogenides (TMDC) show unique optical properties.
This talk proposes a nanostructure based on TMDC which achieves extraordinary transmission levels through a continuous thin metallic film.
Finally, an experimental proof of concept was fabricated without nanopatterning.

Flexible Nitride NWs LED

Speaker: Dr. Nuño Amador.
Organization: Instituto de Sistemas Optoelectrónicos y Microtecnología (ISOM), de la E.T.S.I. Telecomunicación, Universidad Politécnica de Madrid.

Data: May 20th, 2022.
Hours: 10.00 hours.
Place: Room B-222 of the ETSI of Telecommunications of the UPM [Cómo llegar]

ABSTRACT

Flexible light emitting diodes (LEDs) are today a topic of intense research driven by applications such as bendable displays, conformable light sources, bio-medical devices, etc. The conventional inorganic semiconductor devices are mechanically rigid; the fabrication of flexible devices from thin film structures is quite challenging and requires microstructuring and lift-off of the active layer. Instead of two-dimensional films, in this thesis two types of III-nitride nanostructures are studied: (i) bottom-up strategy using core shell nanowires, and (ii) top-down strategy using a porous structure.Polymer-embedded nanowire membranes combine the high efficiency and the long lifetime of inorganic semiconductor materials with the high flexibility and transparency of polymers. I used MOCVD cores shell NWs for the fabrication of flexible blue and green NW LEDs, I also combined them with nanophosphors of different emission color to produce second generation white LED with improved color quality. For the fabrication of red flexible NW LEDs, I tested different strategies, namely all-InGaN route based on In rich InGaN/GaN MQW NWs, downconversion of a blue light by a red phosphor and red emission from GaAsP NWs.

FORC analysis in arrays of interacting nanodots.

Speaker: Alejandro Rivelles.
Organization: Instituto de Sistemas Optoelectrónicos y Microtecnología (ISOM), de la E.T.S.I. Telecomunicación, Universidad Politécnica de Madrid.

Data: April 22nd, 2022.
Hours: 10.00 hours.
Place: Room B-222 of the ETSI of Telecommunications of the UPM [Cómo llegar]

ABSTRACT

FORC (first-order reversal curves) diagrams provide a lot of information about magnetic processes in a magnetic material by analysing a large amount of minor hysteresis loops. Interpretation of these diagrams is not easy, specially in complex systems with strongly interacting elements. Therefore, in many situations FORC diagrams are only used as magnetic signatures more than as a characterization technique. Nanotechnology offers the possibility to synthesize ordered arrays of nanoelements where geometry, spacing and composition determine the interaction between elements. FORC diagrams can reveal quantitative information about magnetic coupling and the magnetization process in such structures. In this work we analyse the interaction between Py and Co circular magnetic nanodots with different geometries.

SAW driven plasmons in graphene heterostructures for sensing ultrathin layers.

Speaker: Raúl Izquierdo López.
Organization: Instituto de Sistemas Optoelectrónicos y Microtecnología (ISOM), de la E.T.S.I. Telecomunicación, Universidad Politécnica de Madrid.

Data: April 1st, 2022.
Hours: 10.00 hours.
Place: Room B-222 of the ETSI of Telecommunications of the UPM [Cómo llegar]

ABSTRACT

The study of the optical properties of materials in the mid IR is of great importance for identifying complex organic compounds, determining both their composition and structure, since the vibrational resonances of the main functional groups lie in this region of the spectrum. The large confinement of graphene plasmon polaritons in the mid IR can be exploited to strengthen light-matter interactions for surface enhanced IR absorption (SEIRA) spectroscopy. In this work, surface acoustic waves are studied as a way to couple far field light into surface plasmon-phonon polaritons in graphene heterostructures, with simulations on the optical properties of the heterostructures and their sensing capabilities and characterization of devices for the generation of surface acoustic waves.

Workshop organized by ISOM-IRIDA, “Maskless Direct Writing and 3D Lithography: Capabilities and Applications”, April 5, 2022, Salón de Actos de Edificio C, ETS Ingenieros de Telecomunicación de la UPM.

From ISOM and in collaboration with IRIDA, we are pleased to invite you to the next Workshop that we will organize at the Universidad Politécnica de Madrid ETSI Telecomunicaciones on April 5, 2022, at 10:00 am, in the Assembly Hall of Building C of the ETS Ingenieros de Telecomunicación of the Universidad Politécnica de Madrid. Avenida Complutense 30. 28040 Madrid. How to get there: https://goo.gl/maps/mWB2dKQeonqVQTCN9

To access the program click on the following link:

Workshop 3D Lithography April 5 2022

If you have any questions or doubts, please send us an email to: info@irida.es