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Sahin Solmaz N, Farsi R, Boero G. 200 GHz single chip microsystems for dynamic nuclear polarization enhanced NMR spectroscopy. Nat Commun 2024; 15:5485. [PMID: 38942752 PMCID: PMC11213862 DOI: 10.1038/s41467-024-49767-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 06/12/2024] [Indexed: 06/30/2024] Open
Abstract
Dynamic nuclear polarization (DNP) is one of the most powerful and versatile hyperpolarization methods to enhance nuclear magnetic resonance (NMR) signals. A major drawback of DNP is the cost and complexity of the required microwave hardware, especially at high magnetic fields and low temperatures. To overcome this drawback and with the focus on the study of nanoliter and subnanoliter samples, this work demonstrates 200 GHz single chip DNP microsystems where the microwave excitation/detection are performed locally on chip without the need of external microwave generators and transmission lines. The single chip integrated microsystems consist of a single or an array of microwave oscillators operating at about 200 GHz for ESR excitation/detection and an RF receiver operating at about 300 MHz for NMR detection. This work demonstrates the possibility of using the single chip approach for the realization of probes for DNP studies at high frequency, high field, and low temperature.
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Affiliation(s)
- Nergiz Sahin Solmaz
- Institute of Electrical and Micro Engineering (IEM) and Center for Quantum Science and Engineering (QSE) École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland.
| | - Reza Farsi
- Institute of Electrical and Micro Engineering (IEM) and Center for Quantum Science and Engineering (QSE) École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
| | - Giovanni Boero
- Institute of Electrical and Micro Engineering (IEM) and Center for Quantum Science and Engineering (QSE) École Polytechnique Fédérale de Lausanne (EPFL), 1015, Lausanne, Switzerland
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2
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Telfah A, Bahti A, Kaufmann K, Ebel E, Hergenröder R, Suter D. Low-field NMR with multilayer Halbach magnet and NMR selective excitation. Sci Rep 2023; 13:21092. [PMID: 38036555 PMCID: PMC10689796 DOI: 10.1038/s41598-023-47689-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 11/16/2023] [Indexed: 12/02/2023] Open
Abstract
This study introduces a low-field NMR spectrometer (LF-NMR) featuring a multilayer Halbach magnet supported by a combined mechanical and electrical shimming system. This setup offers improved field homogeneity and sensitivity compared to spectrometers relying on typical Halbach and dipole magnets. The multilayer Halbach magnet was designed and assembled using three nested cylindrical magnets, with an additional inner Halbach layer that can be rotated for mechanical shimming. The coils and shim-kernel of the electrical shimming system were constructed and coated with layers of zirconia, thermal epoxy, and silver-paste resin to facilitate passive heat dissipation and ensure mechanical and thermal stability. Furthermore, the 7-channel shim coils were divided into two parts connected in parallel, resulting in a reduction of joule heating temperatures from 96.2 to 32.6 °C. Without the shimming system, the Halbach magnet exhibits a field inhomogeneity of approximately 140 ppm over the sample volume. The probehead was designed to incorporate a solenoidal mini coil, integrated into a single planar board. This design choice aimed to enhance sensitivity, minimize [Formula: see text] inhomogeneity, and reduce impedance discrepancies, transmission loss, and signal reflections. Consequently, the resulting linewidth of water within a 3 mm length and 2.4 mm inner diameter sample volume was 4.5 Hz. To demonstrate the effectiveness of spectral editing in LF-NMR applications at 29.934 MHz, we selectively excited hydroxyl and/or methyl protons in neat acetic acid using optimal control pulses calculated through the Krotov algorithm.
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Affiliation(s)
- Ahmad Telfah
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., 44139, Dortmund, Germany
- Nanotechnology Center, The University of Jordan, Amman, 11942, Jordan
- Department of Physics, University of Nebraska at Omaha, Omaha, NE, 68182, USA
| | - Ahmed Bahti
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., 44139, Dortmund, Germany.
- Experimental Physics III, TU Dortmund University, 44227, Dortmund, Germany.
| | - Katharina Kaufmann
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., 44139, Dortmund, Germany
| | - Enno Ebel
- Fachhochschule Dortmund-University of Applied Sciences and Arts, 44139, Dortmund, Germany
| | - Roland Hergenröder
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., 44139, Dortmund, Germany
| | - Dieter Suter
- Experimental Physics III, TU Dortmund University, 44227, Dortmund, Germany.
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3
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Azadmousavi T, Ghafar-Zadeh E. Design and Analysis of a Low-Voltage VCO: Reliability and Variability Performance. MICROMACHINES 2023; 14:2118. [PMID: 38004976 PMCID: PMC10673083 DOI: 10.3390/mi14112118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 11/12/2023] [Accepted: 11/15/2023] [Indexed: 11/26/2023]
Abstract
This paper investigates an adaptive body biasing (ABB) circuit to improve the reliability and variability of a low-voltage inductor-capacitor (LC) voltage-controlled oscillator (VCO). The ABB circuit provides VCO resilience to process variability and reliability variation through the threshold voltage adjustment of VCO's transistors. Analytical equations considering the body bias effect are derived for the most important relations of the VCO and then the performance is verified using the post-layout simulation results. Under a 0.16% threshold voltage shift, the sensitivity of the normalized phase noise and transconductance of the VCO with the ABB circuit compared to the constant body bias (CBB) decreases by around 8.4 times and 3.1 times, respectively. Also, the sensitivity of the normalized phase noise and transconductance of the proposed VCO under 0.16% mobility variations decreases by around 1.5 times and 1.7 times compared to the CBB, respectively. The robustness of the VCO is also examined using process variation analysis through Monte Carlo and corner case simulations. The post-layout results in the 180 nm CMOS process indicate that the proposed VCO draws a power consumption of only 398 µW from a 0.6 V supply when the VCO frequency is 2.4 GHz. It achieves a phase noise of -123.19 dBc/Hz at a 1 MHz offset and provides a figure of merit (FoM) of -194.82 dBc/Hz.
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Affiliation(s)
- Tayebeh Azadmousavi
- Department of Electrical Engineering, University of Bonab, Bonab 55517-61167, Iran;
| | - Ebrahim Ghafar-Zadeh
- Biologically Inspired Sensors and Actuators (BioSA), Department of Electrical Engineering and Computer Science (EECS), Lassonde School of Engineering, York University, Toronto, ON M3J 1P3, Canada
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4
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Becker M, Cheng YT, Voigt A, Chenakkara A, He M, Lehmkuhl S, Jouda M, Korvink JG. Artificial intelligence-driven shimming for parallel high field nuclear magnetic resonance. Sci Rep 2023; 13:17983. [PMID: 37863971 PMCID: PMC10589267 DOI: 10.1038/s41598-023-45021-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 10/14/2023] [Indexed: 10/22/2023] Open
Abstract
Rapid drug development requires a high throughput screening technology. NMR could benefit from parallel detection but is hampered by technical obstacles. Detection sites must be magnetically shimmed to ppb uniformity, which for parallel detection is precluded by commercial shimming technology. Here we show that, by centering a separate shim system over each detector and employing deep learning to cope with overlapping non-orthogonal shimming fields, parallel detectors can be rapidly calibrated. Our implementation also reports the smallest NMR stripline detectors to date, based on an origami technique, facilitating further upscaling in the number of detection sites within the magnet bore.
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Affiliation(s)
- Moritz Becker
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, 76344, Karlsruhe, Germany
| | - Yen-Tse Cheng
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, 76344, Karlsruhe, Germany
| | - Achim Voigt
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, 76344, Karlsruhe, Germany
| | - Ajmal Chenakkara
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, 76344, Karlsruhe, Germany
| | - Mengjia He
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, 76344, Karlsruhe, Germany
| | - Sören Lehmkuhl
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, 76344, Karlsruhe, Germany
| | - Mazin Jouda
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, 76344, Karlsruhe, Germany.
| | - Jan G Korvink
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, 76344, Karlsruhe, Germany.
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5
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Dreyer F, Yang Q, Alnajjar B, Kruger D, Blumich B, Anders J. A Portable Chip-Based NMR Relaxometry System With Arbitrary Phase Control for Point-of-Care Blood Analysis. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2023; 17:831-842. [PMID: 37335792 DOI: 10.1109/tbcas.2023.3287281] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2023]
Abstract
In this article, we present a portable NMR relaxometry system optimized for the point-of-care analysis of body liquids such as blood. The presented system is centered on an NMR-on-a-chip transceiver ASIC, a reference frequency generator with arbitrary phase control, and a custom-designed miniaturized NMR magnet with a field strength of 0.29 T and a total weight of 330 g. The NMR-ASIC co-integrates a low-IF receiver, a power amplifier, and a PLL-based frequency synthesizer on a total chip area of 1100 × 900 μm 2. The arbitrary reference frequency generator enables the use of conventional CPMG and inversion sequences, as well as modified water-suppression sequences. Moreover, it is used to implement an automatic frequency lock to correct temperature-induced magnetic field drifts. Proof-of-concept measurements on NMR phantoms and human blood samples show an excellent concentration sensitivity of v[Formula: see text] = 2.2 mM/[Formula: see text]. This very good performance renders the presented system an ideal candidate for the future NMR-based point-of-care detection of biomarkers such as the blood glucose concentration.
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Cheng YT, Korvink JG, Jouda M. A field focusing butterfly stripline detects NMR at higher signal-to-noise ratio. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2023; 353:107517. [PMID: 37418779 DOI: 10.1016/j.jmr.2023.107517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 06/23/2023] [Accepted: 06/25/2023] [Indexed: 07/09/2023]
Abstract
We present a compact tuned magnetic resonance detector that merges the conductor topology of a butterfly coil with that of a stripline, thereby increasing the magnetic field intensity B1 per unit current, which increases the detection signal-to-noise ratio for mass-limited samples by a factor of 2. The s-parameter measurements further reveal improved radiofrequency shielding through the suppression of B1 outside the coil when operated within an array of similar detectors. Simulations additionally show a sharper B1 fall-off for the butterfly stripline outside the sensitive sample region. Our design is compatible with 2D planar manufacturing procedures, such as printed circuit board technology, and surface micromachining.
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Affiliation(s)
- Yen-Tse Cheng
- Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology, Karlsruhe 76131, Germany
| | - Jan G Korvink
- Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology, Karlsruhe 76131, Germany.
| | - Mazin Jouda
- Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology, Karlsruhe 76131, Germany.
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7
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Cheng YT, Jouda M, Korvink J. Sample-centred shimming enables independent parallel NMR detection. Sci Rep 2022; 12:14149. [PMID: 35986044 PMCID: PMC9389490 DOI: 10.1038/s41598-022-17694-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 07/29/2022] [Indexed: 11/24/2022] Open
Abstract
Two major technical challenges facing parallel nuclear magnetic resonance (NMR) spectroscopy, at the onset, include the need to achieve exceptional [Formula: see text] homogeneity, and good inter-detector radiofrequency signal decoupling, and have remained as technical obstacles that limit high throughput compound screening via NMR. In this contribution, we consider a compact detector system, consisting of two NMR 'unit cell' resonators that implement parallel [Formula: see text] shimming with parallel radiofrequency detection, as a prototype NMR environment, pointing the way towards achieving accelerated NMR analysis. The utility of our approach is established by achieving local field correction within the bore of a 1.05T permanent magnet MRI. Our forerunner platform suppresses signal cross-coupling in the range of [Formula: see text] dB to [Formula: see text] dB, under a geometrically decoupled scheme, leading to a halving of the necessary inter-coil separation. In this permanent magnet environment, two decoupled parallel NMR detector sites simultaneously achieve narrow spectral linewidth, overcoming the spatial inhomogeneity of the magnet from 400 to 28 Hz.
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Affiliation(s)
- Yen-Tse Cheng
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), 76344, Eggenstein-Leopoldshafen, Germany
| | - Mazin Jouda
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), 76344, Eggenstein-Leopoldshafen, Germany.
| | - Jan Korvink
- Institute of Microstructure Technology (IMT), Karlsruhe Institute of Technology (KIT), 76344, Eggenstein-Leopoldshafen, Germany.
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Yang Q, Zhao J, Dreyer F, Krüger D, Anders J. A portable NMR platform with arbitrary phase control and temperature compensation. MAGNETIC RESONANCE (GOTTINGEN, GERMANY) 2022; 3:77-90. [PMID: 37905179 PMCID: PMC10539832 DOI: 10.5194/mr-3-77-2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 04/25/2022] [Indexed: 11/02/2023]
Abstract
In this paper, we present a custom-designed nuclear magnetic resonance (NMR) platform based on a broadband complementary metal-oxide-semiconductor (CMOS) NMR-on-a-chip transceiver and a synchronous reference signal generator, which features arbitrary phase control of the excitation pulse in combination with phase-coherent detection at a non-zero intermediate frequency (IF). Moreover, the presented direct digital synthesis (DDS)-based frequency generator enables a digital temperature compensation scheme similar to classical field locking without the need for additional hardware. NMR spectroscopy and relaxometry measurements verify the functionality of the proposed frequency reference and temperature compensation scheme as well as the overall state-of-the-art performance of the presented system.
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Affiliation(s)
- Qing Yang
- Institute of Smart Sensors, University of Stuttgart, Pfaffenwaldring 47, 70569 Stuttgart, Germany
| | - Jianyu Zhao
- Institute of Smart Sensors, University of Stuttgart, Pfaffenwaldring 47, 70569 Stuttgart, Germany
| | - Frederik Dreyer
- Institute of Smart Sensors, University of Stuttgart, Pfaffenwaldring 47, 70569 Stuttgart, Germany
| | - Daniel Krüger
- Institute of Smart Sensors, University of Stuttgart, Pfaffenwaldring 47, 70569 Stuttgart, Germany
- John A. Paulson School of Engineering and Applied Sciences, Harvard
University, Cambridge, MA 02138, United States
| | - Jens Anders
- Institute of Smart Sensors, University of Stuttgart, Pfaffenwaldring 47, 70569 Stuttgart, Germany
- Center for Integrated Quantum Science and Technology (IQ), Stuttgart, Germany
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Müller-Maatsch J, van Ruth SM. Handheld Devices for Food Authentication and Their Applications: A Review. Foods 2021; 10:2901. [PMID: 34945454 PMCID: PMC8700508 DOI: 10.3390/foods10122901] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 11/18/2021] [Accepted: 11/21/2021] [Indexed: 12/18/2022] Open
Abstract
This review summarises miniaturised technologies, commercially available devices, and device applications for food authentication or measurement of features that could potentially be used for authentication. We first focus on the handheld technologies and their generic characteristics: (1) technology types available, (2) their design and mode of operation, and (3) data handling and output systems. Subsequently, applications are reviewed according to commodity type for products of animal and plant origin. The 150 applications of commercial, handheld devices involve a large variety of technologies, such as various types of spectroscopy, imaging, and sensor arrays. The majority of applications, ~60%, aim at food products of plant origin. The technologies are not specifically aimed at certain commodities or product features, and no single technology can be applied for authentication of all commodities. Nevertheless, many useful applications have been developed for many food commodities. However, the use of these applications in practice is still in its infancy. This is largely because for each single application, new spectral databases need to be built and maintained. Therefore, apart from developing applications, a focus on sharing and re-use of data and calibration transfers is pivotal to remove this bottleneck and to increase the implementation of these technologies in practice.
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Affiliation(s)
- Judith Müller-Maatsch
- Wageningen Food Safety Research, Wageningen University and Research, P.O. Box 230, 6700 EV Wageningen, The Netherlands;
| | - Saskia M. van Ruth
- Wageningen Food Safety Research, Wageningen University and Research, P.O. Box 230, 6700 EV Wageningen, The Netherlands;
- Food Quality and Design, Wageningen University and Research, P.O. Box 17, 6700 AA Wageningen, The Netherlands
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Nassar O, Jouda M, Rapp M, Mager D, Korvink JG, MacKinnon N. Integrated impedance sensing of liquid sample plug flow enables automated high throughput NMR spectroscopy. MICROSYSTEMS & NANOENGINEERING 2021; 7:30. [PMID: 34567744 PMCID: PMC8433180 DOI: 10.1038/s41378-021-00253-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/22/2021] [Accepted: 02/16/2021] [Indexed: 06/13/2023]
Abstract
A novel approach for automated high throughput NMR spectroscopy with improved mass-sensitivity is accomplished by integrating microfluidic technologies and micro-NMR resonators. A flow system is utilized to transport a sample of interest from outside the NMR magnet through the NMR detector, circumventing the relatively vast dead volume in the supplying tube by loading a series of individual sample plugs separated by an immiscible fluid. This dual-phase flow demands a real-time robust sensing system to track the sample position and velocities and synchronize the NMR acquisition. In this contribution, we describe an NMR probe head that possesses a microfluidic system featuring: (i) a micro saddle coil for NMR spectroscopy and (ii) a pair of interdigitated capacitive sensors flanking the NMR detector for continuous position and velocity monitoring of the plugs with respect to the NMR detector. The system was successfully tested for automating flow-based measurement in a 500 MHz NMR system, enabling high resolution spectroscopy and NMR sensitivity of 2.18 nmol s1/2 with the flow sensors in operation. The flow sensors featured sensitivity to an absolute difference of 0.2 in relative permittivity, enabling distinction between most common solvents. It was demonstrated that a fully automated NMR measurement of nine individual 120 μL samples could be done within 3.6 min or effectively 15.3 s per sample.
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Affiliation(s)
- Omar Nassar
- Institute of Microstructure Technology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Mazin Jouda
- Institute of Microstructure Technology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Michael Rapp
- Institute of Microstructure Technology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Dario Mager
- Institute of Microstructure Technology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Jan G. Korvink
- Institute of Microstructure Technology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Neil MacKinnon
- Institute of Microstructure Technology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
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11
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Visschers JC, Wilson E, Conneely T, Mudrov A, Bougas L. Rapid parameter determination of discrete damped sinusoidal oscillations. OPTICS EXPRESS 2021; 29:6863-6878. [PMID: 33726198 DOI: 10.1364/oe.411972] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 01/25/2021] [Indexed: 06/12/2023]
Abstract
We present different computational approaches for the rapid extraction of the signal parameters of discretely sampled damped sinusoidal signals. We compare time- and frequency-domain-based computational approaches in terms of their accuracy and precision and computational time required in estimating the frequencies of such signals, and observe a general trade-off between precision and speed. Our motivation is precise and rapid analysis of damped sinusoidal signals as these become relevant in view of the recent experimental developments in cavity-enhanced polarimetry and ellipsometry, where the relevant time scales and frequencies are typically within the ∼1 - 10 µs and ∼1 - 100 MHz ranges, respectively. In such experimental efforts, single-shot analysis with high accuracy and precision becomes important when developing experiments that study dynamical effects and/or when developing portable instrumentations. Our results suggest that online, running-fashion, microsecond-resolved analysis of polarimetric/ellipsometric measurements with fractional uncertainties at the 10-6 levels, is possible, and using a proof-of-principle experimental demonstration we show that using a frequency-based analysis approach we can monitor and analyze signals at kHz rates and accurately detect signal changes at microsecond time-scales.
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12
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Sahin Solmaz N, Grisi M, Matheoud AV, Gualco G, Boero G. Single-Chip Dynamic Nuclear Polarization Microsystem. Anal Chem 2020; 92:9782-9789. [PMID: 32530638 PMCID: PMC9559634 DOI: 10.1021/acs.analchem.0c01221] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
![]()
Integration
of the sensitivity-relevant electronics of nuclear
magnetic resonance (NMR) and electron spin resonance (ESR) spectrometers
on a single chip is a promising approach to improve the limit of detection,
especially for samples in the nanoliter and subnanoliter range. Here,
we demonstrate the cointegration on a single silicon chip of the front-end
electronics of NMR and ESR detectors. The excitation/detection planar
spiral microcoils of the NMR and ESR detectors are concentric and
interrogate the same sample volume. This combination of sensors allows
one to perform dynamic nuclear polarization (DNP) experiments using
a single-chip-integrated microsystem having an area of about 2 mm2. In particular, we report 1H DNP-enhanced NMR
experiments on liquid samples having a volume of about 1 nL performed
at 10.7 GHz(ESR)/16 MHz(NMR). NMR enhancements as large as 50 are
achieved on TEMPOL/H2O solutions at room temperature. The
use of state-of-the-art submicrometer integrated circuit technologies
should allow the future extension of the single-chip DNP microsystem
approach proposed here up the THz(ESR)/GHz(NMR) region, corresponding
to the strongest static magnetic fields currently available. Particularly
interesting is the possibility to create arrays of such sensors for
parallel DNP-enhanced NMR spectroscopy of nanoliter and subnanoliter
samples.
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Affiliation(s)
- Nergiz Sahin Solmaz
- School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Marco Grisi
- School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Alessandro V. Matheoud
- School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Gabriele Gualco
- School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Giovanni Boero
- School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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