Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 44
Filtrar
1.
Appl Opt ; 63(3): 853-860, 2024 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-38294401

RESUMEN

We present the simulation and design optimization of an integrated light-emitting-diode/photodetector (LED-PD) sensor system for monitoring of light absorbance changes developing in analyte-sensitive compounds. The sensor integrates monolithically both components in a single chip, offering advantages such as downsizing, reduced assembly complexity, and lower power consumption. The changes in the optical parameters of the analyte-sensitive ink are detected by monitoring the power transmission from the LED to the PD. Ray tracing and coupled modeling approach (CMA) simulations are employed to investigate the interaction of the emitted light with the ink. In highly absorbing media, CMA predicts more accurate results by considering evanescent waves. Simulations also suggest that an approximately 39% change in optical transmission can be achieved by adjusting the ink-deposited layer thickness and varying the extinction coefficient from 10-4 to 3×10-4.

2.
Opt Express ; 31(20): 32458-32467, 2023 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-37859048

RESUMEN

Polymer materials have the advantages of a low Young's modulus and low-cost preparation process. In this paper, a polymer-based optical waveguide pressure sensor based on a Bragg structure is proposed. The change in the Bragg wavelength in the output spectrum of the waveguide Bragg grating (WBG) is used to linearly characterize the change in pressure acting on the device. The polymer-based WBG was developed through a polymer film preparation process, and the experimental results show that the output signal of the device has a sensitivity of 1.275 nm/kPa with a measurement range of 0-12 kPa and an accuracy of 1 kPa. The experimental results indicate that the device already perfectly responds to a pulse signal. It has significant potential application value in medical diagnostics and health testing, such as blood pressure monitoring, sleep quality monitoring, and tactile sensing.

3.
Opt Express ; 31(20): 33535-33547, 2023 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-37859133

RESUMEN

Flexible pressure sensors provide a promising platform for artificial smart skins, and photonic devices provide a new technique to fabricate pressure sensors. Here, we present a flexible waveguide-based optical pressure sensor based on a microring structure. The waveguide-based optical pressure sensor is based on a five-cascade microring array structure with a size of 1500 µm × 500 µm and uses the change in output power to linearly characterize the change in pressure acting on the device. The results show that the device has a sensing range of 0-60 kPa with a sensitivity of 23.14 µW/kPa, as well as the ability to detect pulse signals, swallowing, hand gestures, etc. The waveguide-based pressure sensors offer the advantages of good output linearity, high integration density and easy-to-build arrays.

4.
Int Nurs Rev ; 2023 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-37535808

RESUMEN

BACKGROUND: Advanced practice nurse (APN) roles bring great added value to health systems. However, their integration into the health workforce and the sustainability of the role depend on contextual factors surrounding their implementation. AIM: To explore the contextual factors that influence the organization, implementation, and performance of clinical practice among oncology APNs in Catalonia (Spain). METHODS: This is a descriptive qualitative study. A framework of contextual factors was applied to explore the perspectives of 14 oncology APNs in public hospitals in Catalonia by means of semistructured interviews. Data were analyzed according to the thematic analysis approach. The COREQ checklist was used to report the study. RESULTS: APNs in cancer care strongly depend on the hospital environment where they are introduced. Recognition by the multidisciplinary team, the existence of mentoring experiences, and networking between APNs are critical factors that can help or hinder the development and autonomy of the APNs. Likewise, support from nursing managers and directors is decisive in defining the professional profile, establishing accountability mechanisms, and securing financial resources, including economic recognition. Factors related to the external environment can also contribute, including a standardized national APN model and scientific societies. CONCLUSIONS: Contextual factors around clinical practice, institutional structures, and professional networks are crucial determinants for adequately integrating APNs at the health system level. IMPLICATIONS FOR NURSING POLICY: Professional bodies and national nursing organizations should lay the groundwork for defining standards of practice and advocate for specific regulations. In addition, financial recognition and accountability mechanisms to assess the impact of their contribution should be a priority to ensure sustainability and APN satisfaction.

5.
Opt Express ; 31(8): 12072-12082, 2023 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-37157374

RESUMEN

Electro-optic (EO) modulators are typically made of inorganic materials such as lithium niobate; the replacement of these modulators with organic EO materials is a promising alternative due to their lower half-wave voltage (Vπ), ease of handling, and relatively low cost. We propose the design and fabrication of a push-pull polymer electro-optic modulator with voltage-length parameters (VπL) of 1.28 V·cm. The device uses a Mach-Zehnder structure and is made of a second-order nonlinear optical host-guest polymer composed of a CLD-1 chromophore and PMMA polymer. The experimental results show that the loss is 1.7 dB, Vπ drops to 1.6 V, and the modulation depth is 0.637 dB at 1550 nm. The results of a preliminary study show that the device is capable of efficiently detecting electrocardiogram (ECG) signals with performance on par with that of commercial ECG devices.

6.
Data Brief ; 46: 108780, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36478685

RESUMEN

Color QR Codes are often generated to encode digital information, but one also could use colors or to allocate colors in a QR Code to act as a color calibration chart. In this dataset, we present several thousand QR Codes images generated with two different colorization algorithms (random and back-compatible) and several tuning variables in these color encoding. The QR Codes were also exposed to three different channel conditions (empty, augmentation and real-life). Also, we derive the SNR and BER computations for these QR Code in comparison with their black and white versions. Finally, we also show if ZBar, a commercial QR Code scanner, is able to read them.

7.
Eur J Public Health ; 32(6): 852-857, 2022 11 29.
Artículo en Inglés | MEDLINE | ID: mdl-36374643

RESUMEN

BACKGROUND: As a system of European Reference Networks (ERNs) emerges, the differences in quality of care for patients with rare cancers may increase at national level. We aimed to elucidate the processes and healthcare planning principles through which the reference centres (RCs) for rare cancers are embedded in national health systems. METHODS: We used a multiple case-study design based on the experiences of Czechia, Finland, France, Italy, Lithuania and Spain. Using sarcoma as an example of rare cancer, 52 semi-structured interviews were conducted during on-site visits, including a multidisciplinary group of professionals, Ministry of Health professionals, patient representatives and European policymakers. RESULTS: The comparative analysis showed substantial heterogeneity in the processes for formalizing RCs' status and in their levels of integration in the different health systems, but two models (centre-based and the network-based) can be envisaged at national level. RCs for rare cancers were legally established only in France and Spain. Expert clinicians cooperate in a structured way, using network mechanisms, in France and Italy, and these countries, plus Finland and Lithuania, had a referral system to facilitate patients' access from non-expert centres to RCs. Seven key healthcare planning principles in instituting RCs at the national level were identified. CONCLUSIONS: The conditions governing patient access to treatment centres-whether RCs or not-are decided at the national level. It is advisable to progressively align the European and national levels so that the RCs that participate in the ERNs also play a significant role at the national level.


Asunto(s)
Neoplasias , Humanos , España , Italia , Derivación y Consulta , Francia
8.
Opt Express ; 30(23): 41554-41566, 2022 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-36366630

RESUMEN

We demonstrated the design of two different structures, a two-sided structure and a top-surface structure, of glucose waveguide Bragg grating (WBG) sensors in a single-mode silicon-on-insulator (SOI) chip. A two-sided WBG structure was fabricated, and chip preparation was realized by lithography and other processes. A photonic platform for testing the two-sided WBG using glucose was built and completed. When the blood glucose concentration changed by 1 mg/mL, the two-sided WBG had a wavelength offset of 78 pm. The experimental results show that the two structures can achieve the sensing of different blood glucose concentrations. The two-sided WBG had better sensing performance and thus has a wide range of application prospects.


Asunto(s)
Óptica y Fotónica , Silicio , Silicio/química , Refractometría , Glucemia , Automonitorización de la Glucosa Sanguínea , Diseño de Equipo
9.
BMJ Open ; 12(10): e051181, 2022 10 06.
Artículo en Inglés | MEDLINE | ID: mdl-36202578

RESUMEN

OBJECTIVES: Multidisciplinary teams in cancer care are increasingly using information and communication technology (ICT), hospital health information system (HIS) functionalities and ICT-driven care components. We aimed to explore the use of these tools in multidisciplinary team meetings (MTMs) and to identify the critical challenges posed by their adoption based on the perspective of professionals representatives from European scientific societies. DESIGN: This qualitative study used discussion of cases and focus group technique to generate data. Thematic analysis was applied. SETTING: Healthcare professionals working in a multidisciplinary cancer care environment. PARTICIPANTS: Selection of informants was carried out by European scientific societies in accordance with professionals' degree of experience in adopting the implementation of ICT and from different health systems. RESULTS: Professionals representatives of 9 European scientific societies were involved. Up to 10 ICTs, HIS functionalities and care components are embedded in the informational and decision-making processes along three stages of MTMs. ICTs play a key role in opening MTMs to other institutions (eg, by means of molecular tumour boards) and information types (eg, patient-reported outcome measures), and in contributing to the internal efficiency of teams. While ICTs and care components have their own challenges, the information technology context is characterised by the massive generation of unstructured data, the lack of interoperability between systems from different hospitals and HIS that are conceived to store and classify information rather than to work with it. CONCLUSIONS: The emergence of an MTM model that is better integrated in the wider health system context and incorporates inputs from patients and support systems make traditional meetings more dynamic and interconnected. Although these changes signal a second transition in the development process of multidisciplinary teams, they occur in a context marked by clear gaps between the information and management needs of MTMs and the adequacy of current HIS.


Asunto(s)
Tecnología de la Información , Neoplasias , Comunicación , Atención a la Salud , Humanos , Neoplasias/terapia , Grupo de Atención al Paciente
10.
Artículo en Inglés | MEDLINE | ID: mdl-35886665

RESUMEN

The centralization of complex surgical procedures for cancer in Catalonia may have led to geographical and socioeconomic inequities. In this population-based cohort study, we assessed the impacts of these two factors on 5-year survival and quality of care in patients undergoing surgery for rectal cancer (2011-12) and pancreatic cancer (2012-15) in public centers, adjusting for age, comorbidity, and tumor stage. We used data on the geographical distance between the patients' homes and their reference centers, clinical patient and treatment data, income category, and data from the patients' district hospitals. A composite 'textbook outcome' was created from five subindicators of hospitalization. We included 646 cases of pancreatic cancer (12 centers) and 1416 of rectal cancer (26 centers). Distance had no impact on survival for pancreatic cancer patients and was not related to worse survival in rectal cancer. Compared to patients with medium-high income, the risk of death was higher in low-income patients with pancreatic cancer (hazard ratio (HR) 1.46, 95% confidence interval (CI) 1.15-1.86) and very-low-income patients with rectal cancer (HR 5.14, 95% CI 3.51-7.52). Centralization was not associated with worse health outcomes in geographically dispersed patients, including for survival. However, income level remained a significant determinant of survival.


Asunto(s)
Accesibilidad a los Servicios de Salud , Disparidades en el Estado de Salud , Neoplasias Pancreáticas , Neoplasias del Recto , Estudios de Cohortes , Humanos , Neoplasias Pancreáticas/cirugía , Neoplasias Pancreáticas/terapia , Neoplasias del Recto/cirugía , Neoplasias del Recto/terapia , Clase Social , Factores Socioeconómicos , España/epidemiología , Neoplasias Pancreáticas
11.
J Cancer Policy ; 32: 100334, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35594645

RESUMEN

BACKGROUND: Centralisation of cancer surgery is a commonly applied healthcare strategy worldwide. This study aimed to detail the design of centralisation policies, to shed light on the implications of such policies in real practice and to describe the different perspectives taken to deal with difficulties that emerged, taking pancreatic cancer as an example of a complex cancer disease requiring surgery. METHODOLOGY: A scoping review was conducted using the MEDLINE database. We systematically searched for eligible studies published between January 2000 and December 2018. RESULTS: In the 33 included studies, centralisation of pancreatic cancer surgery was implemented through three different models: designated hospitals, definition of minimum volumes per provider, and/or recommendations included in protocols and national guidelines. The presence of highly advanced technology and infrastructures, the availability of extensive service coverage and advanced care processes based on expert multidisciplinary teams, and higher caseloads were identified as key components of centralisation policy. CONCLUSIONS: Centralisation models for pancreatic cancer surgery showed that having expert centres where the care process is comprehensively guided is a foundational policy approach. External quality assessment and the accreditation of centres and professionals performing complex surgical procedures are levers that may positively impact the effectiveness of the measure. POLICY SUMMARY: while we found different experiences and three models of centralisation, all of them were guided by the will to positively impact on pancreatic cancer patients' access to expert care. Clinical research might be able to make progress in the coming years and perhaps contribute to reversing a critical situation of high mortality and growing incidence. However, policymakers must optimise health system responses considering current resources, as suggested by the recommendations proposed in the framework of the EU initiative Bratislava Statement for pancreatic cancer care.


Asunto(s)
Procedimientos Quirúrgicos del Sistema Digestivo , Neoplasias Pancreáticas , Atención a la Salud , Hospitales , Humanos , Neoplasias Pancreáticas/cirugía , Neoplasias Pancreáticas
12.
J Med Internet Res ; 24(3): e29063, 2022 03 10.
Artículo en Inglés | MEDLINE | ID: mdl-35266870

RESUMEN

BACKGROUND: Tumor boards constitute the main consensus and clinical decision-making body of multidisciplinary teams (MDTs) in cancer care. With the increasing clinical complexity of treatment options (eg, targeted therapies, multimodal treatments) and the progressive incorporation of new areas of intervention (eg, survivorship care), tumor boards are now required to play a central role in all cancer processes. However, although frameworks are in place to evaluate MDT quality, only few web-based tools are available for this purpose; indeed, no web-based MDT evaluation tools have been developed for or adapted to the Spanish National Health System. OBJECTIVE: The first aim of this study was to develop a web-based self-assessment model (Autoevaluación de Equipos Multidisciplinares de Atención al Cáncer [AEMAC]) for evaluating multidisciplinary cancer teams in Spain and the second aim was to validate this tool by testing its metric properties, acceptability, and usability. METHODS: We designed and validated the AEMAC program in 3 stages. In the first stage (research), we reviewed the available scientific evidence and performed a qualitative case study of good practice in multidisciplinary care within the Spanish National Health System (n=4 centers and 28 health care professionals). The results were used to define the thematic areas and quality criteria for the self-evaluation model, which were then discussed and validated by a group of experts. The second stage (development) involved the technological development of a web app that would be accessible from any mobile device. In the third stage (piloting and validation), we conducted 4 pilot tests (n=15 tumor boards, 243 professionals) and used the results to analyze the acceptability and usefulness of the tool. RESULTS: We designed a self-assessment model based on 5 thematic areas encompassing a total of 25 quality components, which users rated on a 3-option development scale. The evaluation process, which was managed entirely from the web app, consisted of individual self-assessment, group prioritization, and creation of an improvement plan. Cronbach alpha (.86), McDonald's omega (0.88), and various fit indices (comparative fit index between 0.95 and 1 and goodness-of-fit index between 0.97 and 0.99 for all 5 aspects) confirmed internal consistency. The mean rating for overall satisfaction with the tool and for consistency between the content of the tool and the reality of tumor boards was 7.6 out of 10. CONCLUSIONS: The results obtained during the period of research and piloting of the AEMAC program showed that it has an appropriate structure and metric properties and could therefore be implemented in a real context and generalized to other hospitals. As a virtual tool, it helps to measure the key aspects of MDT quality, such as effectiveness of collaboration and communication, leadership, and the organizational environment.


Asunto(s)
Neoplasias , Autoevaluación (Psicología) , Humanos , Internet , Neoplasias/terapia , Proyectos Piloto , España
13.
Clin Transl Oncol ; 24(8): 1580-1587, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35190961

RESUMEN

INTRODUCTION: Daily, moderate hypofractionation has become standard treatment for breast cancer following breast-conserving surgery, although substantial variation exists in its use. This paper describes the generation of consensus-based recommendations for the utilisation of this therapy at the healthcare system level and compares these to American Society for Radiation Oncology (ASTRO) guidelines. MATERIALS AND METHODS: Consensus-based guidelines were developed in three steps, including a systematic literature review and involvement of radiation oncologists specialising in breast cancer in Catalonia: (a) creation of a working group and evidence review; (b) consideration of the levels of evidence and agreement on the formulation of survey questions; and (c) performance of survey and development of consensus-based recommendations. Results were compared to the ASTRO recommendations. RESULTS: Consensus was above 80% for 10 of the 14 survey items. Experts supported hypofractionated radiotherapy for all breast cancer patients aged 40 years or more; with invasive carcinoma and breast-conserving surgery; without radiation of lymph nodes; and regardless of the tumour size, histological grade, molecular subtype, breast size, laterality, other treatment characteristics, or need for a boost. Over half favoured its use in all situations, even where available scientific evidence is insufficient. The resulting recommendations and the quality of the evidence are comparable to those from ASTRO, despite some differences in the degree of consensus. CONCLUSION: Specialists agree that hypofractionation is the standard treatment for breast cancer following breast-conserving surgery, but some specific areas require a higher level of evidence before unequivocally extending indications.


Asunto(s)
Neoplasias de la Mama , Carcinoma , Oncología por Radiación , Neoplasias de la Mama/patología , Carcinoma/cirugía , Femenino , Humanos , Mastectomía Segmentaria , Hipofraccionamiento de la Dosis de Radiación , Radioterapia Adyuvante/métodos
14.
Radiother Oncol ; 169: 114-123, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-34461186

RESUMEN

BACKGROUND AND PURPOSE: Complex surgery and radiotherapy are the central pillars of loco-regional oncology treatment. This paper describes the reimbursement schemes used in radiation and complex surgical oncology, reports on literature and policy reviews. MATERIAL AND METHODS: A systematic review of the literature of the reimbursement models has been carried out separately for radiotherapy and complex cancer surgery based on PRISMA guidelines. Using searches of PubMed and grey literature, we identified articles from scientific journals and reports published since 2000 on provider payment or reimbursement systems currently used in radiation oncology and complex cancer surgery, also including policy models. RESULTS: Most European health systems reimburse radiotherapy using a budget-based, fee-for-service or fraction-based system; while few reimburse services according to an episode-based model. Also, the reimbursement models for cancer surgery are mostly restricted to differences embedded in the DRG system and adjustments applied to the fees, based on the complexity of each surgical procedure. There is an enormous variability in reimbursement across countries, resulting in different incentives and different amounts paid for the same therapeutic strategy. CONCLUSION: A reimbursement policy, based on the episode of care as the basic payment unit, is advocated for. Innovation should be tackled in a two-tier approach: one defining the common criteria for reimbursement of proven evidence-based interventions; another for financing emerging innovation with uncertain definitive value. Relevant clinical and economic data, also collected real-life, should support reimbursement systems that mirror the actual cost of evidence-based practice.


Asunto(s)
Neoplasias , Oncología por Radiación , Oncología Quirúrgica , Planes de Aranceles por Servicios , Humanos , Neoplasias/radioterapia , Neoplasias/cirugía
15.
Eur J Surg Oncol ; 48(5): 967-977, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-34479744

RESUMEN

BACKGROUND AND PURPOSE: Complex surgery and radiotherapy are the central pillars of loco-regional oncology treatment. This paper describes the reimbursement schemes used in radiation and complex surgical oncology, reports on literature and policy reviews. MATERIAL AND METHODS: A systematic review of the literature of the reimbursement models has been carried out separately for radiotherapy and complex cancer surgery based on PRISMA guidelines. Using searches of PubMed and grey literature, we identified articles from scientific journals and reports published since 2000 on provider payment or reimbursement systems currently used in radiation oncology and complex cancer surgery, also including policy models. RESULTS: Most European health systems reimburse radiotherapy using a budget-based, fee-for-service or fraction-based system; while few reimburse services according to an episode-based model. Also, the reimbursement models for cancer surgery are mostly restricted to differences embedded in the DRG system and adjustments applied to the fees, based on the complexity of each surgical procedure. There is an enormous variability in reimbursement across countries, resulting in different incentives and different amounts paid for the same therapeutic strategy. CONCLUSION: A reimbursement policy, based on the episode of care as the basic payment unit, is advocated for. Innovation should be tackled in a two-tier approach: one defining the common criteria for reimbursement of proven evidence-based interventions; another for financing emerging innovation with uncertain definitive value. Relevant clinical and economic data, also collected real-life, should support reimbursement systems that mirror the actual cost of evidence-based practice.


Asunto(s)
Neoplasias , Oncología por Radiación , Oncología Quirúrgica , Planes de Aranceles por Servicios , Humanos , Neoplasias/radioterapia , Neoplasias/cirugía , Mecanismo de Reembolso
16.
Sensors (Basel) ; 21(10)2021 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-34064543

RESUMEN

Recent research into miniaturized illumination sources has prompted the development of alternative microscopy techniques. Although they are still being explored, emerging nano-light-emitting-diode (nano-LED) technologies show promise in approaching the optical resolution limit in a more feasible manner. This work presents the exploration of their capabilities with two different prototypes. In the first version, a resolution of less than 1 µm was shown thanks to a prototype based on an optically downscaled LED using an LED scanning transmission optical microscopy (STOM) technique. This research demonstrates how this technique can be used to improve STOM images by oversampling the acquisition. The second STOM-based microscope was fabricated with a 200 nm GaN LED. This demonstrates the possibilities for the miniaturization of on-chip-based microscopes.

17.
ESMO Open ; 5(6): e001051, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-33188052

RESUMEN

Pancreatic cancer is one of the most lethal tumours, and it is the fourth cause of cancer death in Europe. Despite its important public health impact, no effective treatments exist, nor are there high-visibility research efforts to improve care. This alarming situation is emblematic of a larger group of cancer diseases, known as neglected cancers. To address the impact of these diseases, the European Commission-supported Innovative Partnership for Action Against Cancer launched a multi-stakeholder initiative to determine key steps that healthcare systems can rapidly implement to improve their response. A working group comprising 20 representatives from European medical societies, patient associations, cancer plan organisations and other relevant European healthcare stakeholders was organised. A consensus process based on the results of different studies, discussion of research outcomes, and development and endorsement of draft statements resulted in 22 consensus recommendations (the Bratislava Statement). The statement argues that substantial improvements can be achieved in patient outcomes by centralising pancreatic cancer care around state-of-the-art reference centres, staffed by expert multidisciplinary teams capable of providing high-quality care. This organisational model requires a specific care framework encompassing primary, palliative and survivorship care, and a policy environment prioritising the use of quality criteria and performance assessments as well as research investments dedicated to prevention, risk prediction, early detection and diagnosis. In order to address the challenges posed by neglected cancers in general and pancreatic cancer in particular, a specific control strategy tailored to this reality is required.


Asunto(s)
Neoplasias Pancreáticas , Calidad de la Atención de Salud , Consenso , Europa (Continente) , Humanos , Cuidados Paliativos
18.
Nanomaterials (Basel) ; 10(5)2020 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-32466114

RESUMEN

The realization of a fully integrated group IV electrically driven laser at room temperature is an essential issue to be solved. We introduced a novel group IV side-emitting laser at a wavelength of 1550 nm based on a 3-layer Ge/Si quantum well (QW). By designing this scheme, we showed that the structural, electronic, and optical properties are excited for lasing at 1550 nm. The preliminary results show that the device can produce a good light spot shape convenient for direct coupling with the waveguide and single-mode light emission. The laser luminous power can reach up to 2.32 mW at a wavelength of 1550 nm with a 300-mA current. Moreover, at room temperature (300 K), the laser can maintain maximum light power and an ideal wavelength (1550 nm). Thus, this study provides a novel approach to reliable, efficient electrically pumped silicon-based lasers.

19.
Sensors (Basel) ; 20(3)2020 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-32033470

RESUMEN

In this work, we present conductometric gas sensors based on p-type calcium iron oxide (CaFe2O4) nanoparticles. CaFe2O4 is a metal oxide (MOx) with a bandgap around 1.9 eV making it a suitable candidate for visible light-activated gas sensors. Our gas sensors were tested under a reducing gas (i.e., ethanol) by illuminating them with different light-emitting diode (LED) wavelengths (i.e., 465-640 nm). Regardless of their inferior response compared to the thermally activated counterparts, the developed sensors have shown their ability to detect ethanol down to 100 ppm in a reversible way and solely with the energy provided by an LED. The highest response was reached using a blue LED (465 nm) activation. Despite some responses found even in dark conditions, it was demonstrated that upon illumination the recovery after the ethanol exposure was improved, showing that the energy provided by the LEDs is sufficient to activate the desorption process between the ethanol and the CaFe2O4 surface.

20.
Microsyst Nanoeng ; 6: 88, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-34567698

RESUMEN

The rapid development of display technologies has raised interest in arrays of self-emitting, individually controlled light sources atthe microscale. Gallium nitride (GaN) micro-light-emitting diode (LED) technology meets this demand. However, the current technology is not suitable for the fabrication of arrays of submicron light sources that can be controlled individually. Our approach is based on nanoLED arrays that can directly address each array element and a self-pitch with dimensions below the wavelength of light. The design and fabrication processes are explained in detail and possess two geometries: a 6 × 6 array with 400 nm LEDs and a 2 × 32 line array with 200 nm LEDs. These nanoLEDs are developed as core elements of a novel on-chip super-resolution microscope. GaN technology, based on its physical properties, is an ideal platform for such nanoLEDs.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...