Article
Engineering, Electrical & Electronic
Lijuan Su, Jonathan Munoz-Enano, Paris Velez, Pau Casacuberta, Marta Gil, Ferran Martin
Summary: This paper presents a phase-variation microwave sensor using a high-impedance half-wavelength sensing line, useful for dielectric constant measurements and characterization of materials. By increasing the characteristic impedance of the sensing line, the sensitivity to small perturbations is enhanced, resulting in a 2.1 times larger sensitivity compared to traditional matched-line implementations.
IEEE SENSORS JOURNAL
(2021)
Article
Engineering, Electrical & Electronic
Chao-Hsiung Tseng, Chu-Hsuan Pai, Hsiu-Che Chang
Summary: This article proposes a microwave oscillator-based microfluidic sensor for measuring the dielectric constant. The sensor is sensitive, compact, and has a self-sustaining microwave test source, making it a potential practical organic chemical sensor for industrial applications.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2023)
Article
Engineering, Electrical & Electronic
Mate Kalovics, Kristof Ivan, Zsolt Szabo
Summary: A microfluidic mixer is integrated with a dual-band microwave resonator for in situ monitoring of liquid mixing. The mixer utilizes a complementary double split-ring resonator etched in the ground plane of a microstrip transmission line. Through simulations, optimal channel configurations are designed to increase sensitivity, minimize required sample volume, and eliminate unwanted microfluidic mixing. The device allows for unambiguous chemical identification by monitoring the frequency variation of resonances.
IEEE SENSORS JOURNAL
(2023)
Article
Computer Science, Information Systems
Yevhen Yashchyshyn, Krzysztof Derzakowski, Changying Wu, Grzegorz Cywinski
Summary: This paper describes a novel W-band sensor based on reflectometer method for measuring the complex permittivity of rod shaped samples. By using a cylindrical waveguide with the TE01 mode, it overcomes the challenge of characterizing dielectric materials around 100 GHz. The complex field structure in the sensor makes it impossible to apply a standard calibration method. Simulation and experimental results demonstrate the robustness of this new sensor for characterizing rod shaped dielectric samples.
Article
Engineering, Electrical & Electronic
Mehdi S. Ferhat, Tulio Honorio, Thierry Bore, Farid Benboudjema, Franck Daout, Eric Vourc'h
Summary: This article monitors the hydration process of cement mortar using calorimetry and microwave reflectometry. The data from both techniques are consistent and a mechanistic model is developed to describe the dielectric properties of the mortar during hydration.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
Article
Engineering, Electrical & Electronic
Lijuan Su, Jonathan Munoz-Enano, Paris Velez, Pau Casacuberta Orta, Marta Gil, Ferran Martin
Summary: The article introduces a sensor based on reflective-mode step-impedance transmission line, which is implemented in coplanar waveguide to increase sensitivity. The sensor is useful for dielectric characterization of solids and liquids, and measurement of variables related to changes in the dielectric constant of the material under test.
IEEE SENSORS JOURNAL
(2021)
Article
Engineering, Electrical & Electronic
Yuan Yu, Shuai Cui, Guijiang Yang, Luoqiu Xu, Yu Chen, Kaixiang Cao, Liang Wang, Yu Yu, Xinliang Zhang
Summary: We proposed and demonstrated a temperature sensor with both high resolution and large dynamic range based on simultaneous microwave photonic and optical measurements. By designing and fabricating two cascaded ring resonators (CRRs) with different temperature sensitivities and free spectral ranges (FSRs) as the sensing probe, and utilizing the ultrahigh-Q-factor microring in the CRR, we achieved a high temperature resolution with a microwave photonic notch filter (MPNF) and a large dynamic range with the optical transmission spectrum of the CRR. The combination of these two measurements realized the desired temperature sensor.
IEEE SENSORS JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Arda Secme, Uzay Tefek, Burak Sari, Hadi Sedaghat Pisheh, H. Dilara Uslu, Ozge Akbulut Caliskan, Berk Kucukoglu, Ramazan Tufan Erdogan, Hashim Alhmoud, Ozgur Sahin, M. Selim Hanay
Summary: Microwave sensors combined with optical sensing can be used to probe material properties and track size changes of microscale objects. In this study, we designed and fabricated two types of planar sensors, the CPW resonator and the SRR, to detect single cells and particles. The results show that microwave sensing technology can serve as a complementary technique for single-cell biophysical experiments and microscale pollutant screening.
IEEE SENSORS JOURNAL
(2023)
Article
Nanoscience & Nanotechnology
Arda Secme, Hadi Sedaghat Pisheh, Uzay Tefek, H. Dilara Uslu, Berk Kucukoglu, Ceren Alatas, Mehmet Kelleci, M. Selim Hanay
Summary: Precise monitoring of fluid flow rates is crucial in lab-on-a-chip applications. This study explores the use of a 220 nm thick Silicon Nitride membrane as an on-chip sensing mechanism for flow rate measurement. By inducing mechanical deformations on the membrane through applied pressure and fluid flow, changes in capacitance and resonance frequency of an integrated microwave resonator are observed and used to track the flow rate. The membrane exhibits both deflection under pressure and pulsation under constant fluid flow, providing separate sensing mechanisms for pressure and flow rate. This research demonstrates the potential of microwave resonators for fluid-structure interactions at micro- and nanoscales.
MICROFLUIDICS AND NANOFLUIDICS
(2023)
Review
Chemistry, Analytical
Laura Jasinska, Karol Malecha
Summary: The increase in microfluidic-microwave devices can be attributed to the ease of integrating microwave circuits and microfluidic components, as well as the four main manufacturing trends and three main application fields of these devices. These devices are used for dielectric heating, microwave-based detection, and microwave-enhanced chemistry, with functionalities including heating or delivering microwave power and detecting dielectric parameters in liquid channels.
Article
Engineering, Electrical & Electronic
Weina Liu, Junjie Zhang, Lei Xu
Summary: A miniaturized broadband CPW sensor with enhanced sensitivity is proposed in this paper for measuring electrolyte concentration in biological fluids. The sensor is fabricated using PCB technology and calibrated based on microwave network theory. Experiments demonstrate that the sensor has a high sensitivity and robustness against external factors, making it suitable for low-cost, real-time sensing technologies.
IEEE SENSORS JOURNAL
(2021)
Article
Chemistry, Analytical
Atena Amanati Shahri, Amir Hossein Omidvar, Gustavo Pamplona Rehder, Ariana Lacorte Caniato Serrano
Summary: A label-free, sensitive, miniaturized sensing device has been developed for detecting living cells in their flow stream. Through the integration of a microstrip stub resonator above a microfluidic structure using metallic nanowire-filled membrane technology, this biosensor demonstrates outstanding performance in distinguishing living cells in cell suspension. The device takes advantage of the uniform and concentrated field distribution between the tip of the stub resonator and its ground plane as the substrate, where the cell suspension flows in a microfluidic channel. By studying the changes in relative permittivity caused by the presence of a single living cell in the phase of the transmitted signal (S-21), an average variation of as much as 22.85 +/- 1.65 degrees at approximately 11.1 GHz is observed for living cell sensing with this optimized device. This biosensor can detect rapidly flowing cells in their biological medium in real-time, making it a potential tool for early disease diagnosis and monitoring.
Review
Chemistry, Analytical
Mohammad Abdolrazzaghi, Vahid Nayyeri, Ferran Martin
Summary: This review article provides a comprehensive outlook on various methodologies to enhance the sensitivity, resolution, and robustness of arbitrary microwave sensors. Practical approaches with prototype examples are presented, and the main applications of these procedures are reported. Sensors implementing the proposed techniques show higher performance for high-end and real-life use.
Article
Environmental Sciences
Zoltan Jakoi, Cecilia Hodur, Sandor Beszedes
Summary: Anaerobic digestion of wastewater sludge is a promising and efficient method for wastewater and sludge treatment. This study focused on the applicability of measuring techniques, specifically viscosity and dielectric measurement. The results showed that microwave pre-treatment enhances fermentation and reduces viscosity, while not changing the overall tendencies of the anaerobic digestion process. Additionally, dielectric and absolute viscosity measurements were effective methods for monitoring the fermentation process.
Article
Engineering, Electrical & Electronic
Pavan K. Kota, Daniel LeJeune, Rebekah A. Drezek, Richard G. Baraniuk
Summary: Compressed sensing is a signal processing technique that efficiently recovers sparse high-dimensional signals from low-dimensional measurements. This study explores the multiple measurement vector problem where signals are independently drawn from a sparse multivariate Poisson distribution. Through maximum likelihood estimation and a novel Sparse Poisson Recovery algorithm, the sparse parameter vector of Poisson rates is successfully recovered.
IEEE TRANSACTIONS ON SIGNAL PROCESSING
(2022)
Article
Biochemical Research Methods
Andrea Folli, Heungjae Choi, Michael Barter, Jaafar Harari, Emma Richards, Daniel Slocombe, Adrian Porch, Damien M. Murphy
JOURNAL OF MAGNETIC RESONANCE
(2020)
Article
Engineering, Manufacturing
Richard Gumbleton, Jerome A. Cuenca, Georgina M. Klemencic, Nick Jones, Adrian Porch
ADDITIVE MANUFACTURING
(2019)
Article
Engineering, Electrical & Electronic
Hayder Hamzah, Ali A. Abduljabar, Adrian Porch
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2020)
Article
Public, Environmental & Occupational Health
M. J. Pascoe, A. Robertson, A. Crayford, E. Durand, J. Steer, A. Castelli, R. Wesgate, S. L. Evans, A. Porch, J-Y. Maillard
JOURNAL OF HOSPITAL INFECTION
(2020)
Article
Engineering, Electrical & Electronic
Ali A. Abduljabar, Hayder Hamzah, Adrian Porch
Summary: This paper presents a new type of microwave microfluidic sensor using three separate half wave microstrip resonators with resonant frequencies of 2.5, 3.5, and 4.5 GHz. The sensor demonstrates advantages of microwave resonant methods for dielectric liquid characterization such as high precision, accuracy, and sensitivity across a wideband of frequencies. Experimental results for testing with water, methanol, ethanol, and chloroform show excellent agreement with simulation results.
MICROWAVE AND OPTICAL TECHNOLOGY LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Richard Gumbleton, Jerome A. Cuenca, Samuel Hefford, Kenneth Nai, Adrian Porch
Summary: The study measured the surface resistance of additive manufactured and traditionally machined samples using a parallel plate microwave resonator, with very small errors. For additive manufactured AlSi10Mg alloy samples, it was found that directional roughness features on the surface had minimal impact on surface resistance.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2021)
Article
Chemistry, Multidisciplinary
Rene Riedel, Andrew G. Seel, Daniel Malko, Daniel P. Miller, Brendan T. Sperling, Heungjae Choi, Thomas F. Headen, Eva Zurek, Adrian Porch, Anthony Kucernak, Nicholas C. Pyper, Peter P. Edwards, Anthony G. M. Barrett
Summary: The study presents experimental and computational data supporting ion pairing in alkalide solutions, and reveals the presence of superalkali-alkalide ion pairs. Temperature-dependent NMR measurements show that the dynamics of alkalide species is reversible and thermally activated, indicating a complex exchange process for ion-paired species. The results go beyond the traditional gaslike anion picture, emphasizing the significance of interactions between alkalide and its complex countercation (superalkali).
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Physics, Atomic, Molecular & Chemical
Michael Barter, Giuseppina Magri, Jaafar Harari, Heungjae Choi, Andrea Folli, Daniel R. Slocombe, Emma Richards, Damien M. Murphy, Adrian Porch
Summary: This paper describes the design considerations for a dual mode X-band continuous wave (CW) Electron Paramagnetic Resonance (EPR) cavity, which allows for simultaneous EPR measurement and microwave heating. The chosen elliptical cavity geometry splits the degeneracy of the TM110 mode, providing effective EPR signal resolution. The use of copper clad laminates for the cavity walls ensures sufficient penetration of the modulation field and maintains a high cavity Q factor. The heating port and low pass filter compensate for the decrease in EPR signal strength.
APPLIED MAGNETIC RESONANCE
(2022)
Article
Chemistry, Multidisciplinary
Giuseppina Magri, Michael Barter, Jack Fletcher-Charles, Heungjae Choi, Daniel Slocombe, Emma Richards, Andrea Folli, Adrian Porch, Damien M. Murphy
Summary: A custom-built dual-mode EPR resonator was used to study the radical chemistry of AIBN thermal decomposition. The results showed that the distribution of radicals observed by EPR varied under different heating conditions. Microwave-induced heating provided faster and easier heating capabilities but may lead to the non-detection of radical intermediates.
RESEARCH ON CHEMICAL INTERMEDIATES
(2023)
Article
Engineering, Electrical & Electronic
D. R. Jones, P. Brown, G. McFarland, R. Perks, H. Choi, S. Cripps, A. Porch
Summary: This article introduces a method of using near-field scanning microwave microscopy for 3D surface metrology. By measuring the change in capacitance between the probe and the sample surface, as well as the shift in resonance frequency, structures of various materials can be analyzed.
IEEE JOURNAL OF MICROWAVES
(2023)
Article
Chemistry, Physical
Rebekah L. Taylor, Duncan Housley, Michael Barter, Adrian Porch, Keith Whiston, Andrea Folli, Damien M. Murphy
Summary: This study investigated the influence of varying water/acetic acid ratios on the structure and coordination environment of Co/Mn/Br catalyst, suggesting tetrahedral Co2+ species form with 2 or 3 Br- ligands at low water content. EPR linewidth changes in Mn2+ signals were correlated with water content, showing variations in coordination sphere. Findings provide insight into the relationship between solvent composition and catalyst structure.
CATALYSIS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Physical
Michael Barter, Gemma Smith, Sihai Yang, Martin Schroder, Martin Owen Jones, Adrian Porch
Summary: The combination of simultaneous neutron powder diffraction and microwave characterization offers more information than either technique alone, particularly at high temperatures. This paper outlines the design of equipment for these techniques and demonstrates the successful desolvation of a metal-organic framework sample at 150 degrees Celsius using this equipment. The high sensitivity of microwave characterization for lossy and polar materials is shown to detect levels much lower than those detectable by crystallographic techniques.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Computer Science, Information Systems
Richard Gumbleton, Robert Batson, Kenneth Nai, Adrian Porch
Summary: This paper explores the adoption of metal additive manufacturing in the production of passive microwave components, highlighting its advantages in geometrical design freedom and weight reduction, while also addressing some challenges in terms of microwave surface resistance values.
Article
Engineering, Electrical & Electronic
Samuel Hefford, Nicholas Clark, Richard Gumbleton, Adrian Porch
Summary: A new method for accurately measuring the microwave surface resistance of flat metal plates is proposed and experimentally verified using a sapphire dielectric resonator. System losses are taken into account by continuously and controlled varying the distance between the dielectric and the sample under test.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2021)
Article
Engineering, Electrical & Electronic
Jerome A. Cuenca, Soumen Mandal, David J. Morgan, Malcolm Snowball, Adrian Porch, Oliver A. Williams
ACS APPLIED ELECTRONIC MATERIALS
(2020)
