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F. Arroyo Cardoso
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6 records found
1
This work investigates the thermoelectric properties of a gallium nitride (GaN)-based two-dimensional hole gas (2DHG) using a double heterojunction, which can be utilized in complementary GaN thermoelectric (TE) platforms for power generation in extreme environments. A 5 × 1012cm−2 hole density, a Hall mobility of up to 20 cm2 V−1s−1, and a Seebeck coefficient of 0.4 mV K−1 have been measured, resulting in a power factor of 0.5-1.0 mW m−1K−2 over a 300–77 K temperature range. These results demonstrate the stability and usability of the thermoelectric properties of GaN using hole conduction at sub-100 K temperatures, therefore providing clear evidence that GaN-based 2DHGs can function as a stable cryogenic TE platform, opening new opportunities for complementary device architectures (leveraging both 2DHGs for p-type and two-dimensional electron gases for n-type) optimized for extreme environment electronics commonly encountered in deep-space missions, where other materials become unreliable.
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This work investigates the thermoelectric properties of a gallium nitride (GaN)-based two-dimensional hole gas (2DHG) using a double heterojunction, which can be utilized in complementary GaN thermoelectric (TE) platforms for power generation in extreme environments. A 5 × 1012cm−2 hole density, a Hall mobility of up to 20 cm2 V−1s−1, and a Seebeck coefficient of 0.4 mV K−1 have been measured, resulting in a power factor of 0.5-1.0 mW m−1K−2 over a 300–77 K temperature range. These results demonstrate the stability and usability of the thermoelectric properties of GaN using hole conduction at sub-100 K temperatures, therefore providing clear evidence that GaN-based 2DHGs can function as a stable cryogenic TE platform, opening new opportunities for complementary device architectures (leveraging both 2DHGs for p-type and two-dimensional electron gases for n-type) optimized for extreme environment electronics commonly encountered in deep-space missions, where other materials become unreliable.
Journal article
(2025)
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Mohammad Javad Bathaei, Sina Hashemizadeh, Filipe Arroyo Cardoso, Denys Nikolayev, Clementine M. Boutry
This letter presents the first fabrication and characterization of a biodegradable coaxial cavity resonator, focusing on the measurement of complex permittivity of encapsulation as well as |S11| and impedance parameters. The resonator components are 3D-printed from plant-based resin, coated with silver-coated copper flakes, and enclosed by a laser-cut zinc membrane. A monopole coupler antenna, inspired by the “Great Seal Bug,” is co-designed with the cavity to enable near-field coupling and achieve frequency-selective, near- 50 Ω impedance-matched wireless sensing. Numerical and experimental analysis of the gap between post and membrane (G-post), and between the coupler antenna and post, resulted in| S11 | of −30.3 dB at 1.7 GHz, and a quality factor of 307, outperforming existing flat biodegradable resonators. A 40-MHz resonance shift is observed with a 20 μm variation in G-post, highlighting the resonator’s high sensitivity to membrane position. This system enables battery-free wireless sensing with biodegradable antennas for biodiversity monitoring.
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This letter presents the first fabrication and characterization of a biodegradable coaxial cavity resonator, focusing on the measurement of complex permittivity of encapsulation as well as |S11| and impedance parameters. The resonator components are 3D-printed from plant-based resin, coated with silver-coated copper flakes, and enclosed by a laser-cut zinc membrane. A monopole coupler antenna, inspired by the “Great Seal Bug,” is co-designed with the cavity to enable near-field coupling and achieve frequency-selective, near- 50 Ω impedance-matched wireless sensing. Numerical and experimental analysis of the gap between post and membrane (G-post), and between the coupler antenna and post, resulted in| S11 | of −30.3 dB at 1.7 GHz, and a quality factor of 307, outperforming existing flat biodegradable resonators. A 40-MHz resonance shift is observed with a 20 μm variation in G-post, highlighting the resonator’s high sensitivity to membrane position. This system enables battery-free wireless sensing with biodegradable antennas for biodiversity monitoring.
Journal article
(2025)
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J. Bathaei, E.Y. Özüaçıksöz, Z. Liao, M. Yazdan Mehr, Filipe Arroyo Cardoso, C.M. Boutry
The emergence of a new family of wireless biodegradable sensors marks a groundbreaking leap in ecological and environmental sensing. These biodegradable devices can collect a wide range of data in agriculture, climate research, forestry, water management, and biodiversity protection. Manufactured primarily from environmentally safe transient materials for sensing and data transmission, these systems undergo controlled degradation after use, minimizing environmental electronic waste. Here, a critical review of key aspects in the development and application of biodegradable sensors is performed for ecological and environmental monitoring. First, the different materials utilized in the development of biodegradable environmental monitoring devices and their applications are explored. The relevant degradation mechanisms, including hydrolysis, oxidation, photodegradation, and micro-organism action are examined as a function of environmental conditions. Then compatible and non-toxic fabrication techniques are investigated for building biodegradable sensors, emphasizing their scalability and potential for mass production. Finally, system-level considerations are discussed for sustainable powering of these devices, ensuring efficient operation while maintaining environmental sustainability. By surveying a broad spectrum of applications and ongoing advancements, it is argued that biodegradable sensors have a transformative potential in advancing sustainable, widespread, and cost-effective ecological and environmental monitoring solutions.
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The emergence of a new family of wireless biodegradable sensors marks a groundbreaking leap in ecological and environmental sensing. These biodegradable devices can collect a wide range of data in agriculture, climate research, forestry, water management, and biodiversity protection. Manufactured primarily from environmentally safe transient materials for sensing and data transmission, these systems undergo controlled degradation after use, minimizing environmental electronic waste. Here, a critical review of key aspects in the development and application of biodegradable sensors is performed for ecological and environmental monitoring. First, the different materials utilized in the development of biodegradable environmental monitoring devices and their applications are explored. The relevant degradation mechanisms, including hydrolysis, oxidation, photodegradation, and micro-organism action are examined as a function of environmental conditions. Then compatible and non-toxic fabrication techniques are investigated for building biodegradable sensors, emphasizing their scalability and potential for mass production. Finally, system-level considerations are discussed for sustainable powering of these devices, ensuring efficient operation while maintaining environmental sustainability. By surveying a broad spectrum of applications and ongoing advancements, it is argued that biodegradable sensors have a transformative potential in advancing sustainable, widespread, and cost-effective ecological and environmental monitoring solutions.
Emerging biomedical ultrasound applications such as pulsed neurostimulation and shear-wave imaging demand single-pulse focused ultrasound waves with MPa-range acoustic pressures. Achieving high pressures typically involves driving transducers with high voltages, necessitating bulky power amplifiers. Recently, phased arrays have emerged to miniaturize these focused transducers. However, they often exhibit poor power efficiency and heat dissipation. To address this, we explore acoustic amplification through acoustic energy storage and release, where, with minimal voltage, high-amplitude ultrasound waves are produced. Prior work has shown the principle using bulky apparatus with limited applicability. In this work, we explore the theory and perform finite element modeling (FEM) to investigate this mechanism with miniaturized and micro-electro-mechanical systems (MEMS)-compatible materials and geometries.
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Emerging biomedical ultrasound applications such as pulsed neurostimulation and shear-wave imaging demand single-pulse focused ultrasound waves with MPa-range acoustic pressures. Achieving high pressures typically involves driving transducers with high voltages, necessitating bulky power amplifiers. Recently, phased arrays have emerged to miniaturize these focused transducers. However, they often exhibit poor power efficiency and heat dissipation. To address this, we explore acoustic amplification through acoustic energy storage and release, where, with minimal voltage, high-amplitude ultrasound waves are produced. Prior work has shown the principle using bulky apparatus with limited applicability. In this work, we explore the theory and perform finite element modeling (FEM) to investigate this mechanism with miniaturized and micro-electro-mechanical systems (MEMS)-compatible materials and geometries.
Muscle plays a vital role in movement and metabolic regulation, establishing it as a cornerstone of overall health. Monitoring muscular parameters is critical for disease diagnosis, post-surgical recovery, and human–machine interface control. In recent decades, numerous technologies have emerged to monitor muscular biophysical and biochemical processes. The field has transitioned significantly from reliance on large, clinic-bound instrumentation to the development of miniaturized wearable and implantable systems capable of continuous real-time monitoring in everyday settings. This article presents a critical overview of recent advances, with a focus on material and device innovations in muscular monitoring. Starting with the fundamental characteristics of muscle tissue and the physiological origins of biosignals, the discussion subsequently shifts to recent developments in wearable and implantable bioelectronic systems tailored to monitor electrophysiological, biomechanical, and tissue oxygenation signals. Finally, current research challenges and outline emerging opportunities are highlighted in muscular monitoring. Owing to its interdisciplinary nature and growing societal demand for personalized healthcare, muscular monitoring is poised to catalyze transformative innovations in both clinical and consumer applications.
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Muscle plays a vital role in movement and metabolic regulation, establishing it as a cornerstone of overall health. Monitoring muscular parameters is critical for disease diagnosis, post-surgical recovery, and human–machine interface control. In recent decades, numerous technologies have emerged to monitor muscular biophysical and biochemical processes. The field has transitioned significantly from reliance on large, clinic-bound instrumentation to the development of miniaturized wearable and implantable systems capable of continuous real-time monitoring in everyday settings. This article presents a critical overview of recent advances, with a focus on material and device innovations in muscular monitoring. Starting with the fundamental characteristics of muscle tissue and the physiological origins of biosignals, the discussion subsequently shifts to recent developments in wearable and implantable bioelectronic systems tailored to monitor electrophysiological, biomechanical, and tissue oxygenation signals. Finally, current research challenges and outline emerging opportunities are highlighted in muscular monitoring. Owing to its interdisciplinary nature and growing societal demand for personalized healthcare, muscular monitoring is poised to catalyze transformative innovations in both clinical and consumer applications.
Book chapter
(2022)
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José Germano, Tiago Costa, Filipe Arroyo Cardoso, José Amaral, Susana Cardoso, Paulo P Freitas, Moisés S Piedade