Jan Gerrit Korvink

Jan Gerrit Korvink
Karlsruhe Institute of Technology | KIT · Institute of Microstructure Technology

Dr. sc. techn.; M.Sc.(eng); B.Eng.

About

664
Publications
103,075
Reads
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8,759
Citations
Introduction
My current research focuses towards lab on a chip systems (MEMS) for high resolution MRI and NMR, with applications in the life sciences (metabolomics), chemistry, and materials science. I also work on inkjetting as a micro-manufacturing platform, and on spectroscopy micro-systems in general.
Additional affiliations
April 2015 - present
Karlsruhe Institute of Technology
Position
  • Professor for Microstructure Technology
January 2002 - December 2003
January 1998 - March 2015
University of Freiburg
Position
  • Professor for Microsystems Engineering
Education
January 1987 - December 1993
ETH Zurich
Field of study
January 1985 - December 1986
Cape Town
Field of study
January 1983 - December 1984

Publications

Publications (664)
Article
A labeling strategy for in vivo 19F‐MRI (magnetic resonance imaging) based on highly fluorinated, short hydrophilic peptide probes, is developed. As dual‐purpose probes, they are functionalized further by a fluorophore and an alkyne moiety for bioconjugation. High fluorination is achieved by three perfluoro‐tert‐butyl groups, introduced into aspara...
Article
Full-text available
Two major technical challenges facing parallel nuclear magnetic resonance (NMR) spectroscopy, at the onset, include the need to achieve exceptional B0 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 conside...
Preprint
This paper presents a topology optimization approach for the surface flows on variable design domains. Via this approach, the matching between the pattern of a surface flow and the 2-manifold used to define the pattern can be optimized, where the 2-manifold is implicitly defined on another fixed 2-manifold named as the base manifold. The fiber bund...
Article
Full-text available
Extreme point-of-care refers to medical testing in unfavorable conditions characterized by a lack of primary resources or infrastructure. As witnessed in the recent past, considerable interest in developing devices and technologies exists for extreme point-of-care applications, for which the World Health Organization has introduced a set of encoura...
Article
Surface flows can represent the motions of the viscous and incompressible fluid at the solid/fluid interfaces. This paper presents a topology optimization approach for surface flows and extends the design space of topology optimization of fluidic structures onto the curved surfaces in the forms of 2-manifolds corresponding to the geometrical config...
Article
Full-text available
This work establishes carbon nanofibre-mediated patterning of metal oxide nanostructures, through the combination of electrospinning and vapor-phase transport growth. Electrospinning of a suitable precursor with subsequent carbonization results in the patterning of catalyst gold nanoparticles embedded within carbon nanofibres. During vapor-phase tr...
Conference Paper
The promising automation of flexible surgical instruments and robots is impeded by the lack of sensory means, which allow for sensing of an instrument’s position to the surrounding tissue. This work presents a novel sensory method utilizing capacitive proximity sensing to derive a relative localization of a flexible instrument inside a hollow organ...
Article
In this article, we report on a technological approach for miniaturization inductive levitating micro-suspension based on the nested 3D micro-coil structures. In the developed approach, each 3D micro-coil is fabricated separately, beginning with the innermost and thus smallest coil diameter of the nested microstructure. This helps to overcome fabri...
Article
The design methods for gradient coils are mostly based on discrete extrinsic methods (e.g., the Biot–Savart integration calculation), for which the surface normal vector strongly influences any numerical calculation of the discretized surface. Previous studies are mostly based on regular or analytical surfaces, which allow normal vectors to be expr...
Article
The net phase of the NMR signal is proposed as a robust mechanism for the encoding of fluid flow velocity into phase, showing local bijectivity. While magnitude-based or imaging-based methods suffer from loss of signal, by increasing the flow rate, the present method enables us to maintain the high SNR even for the case of fast flow. In addition, i...
Chapter
Paul Callaghan's book is perhaps the first publication to consider magnetic resonance imaging (MRI) in the same light as optical microscopy. “One cubic millimeter of cerebral cortex contains roughly 50,000 neurons, each of which establishes approximately 6,000 synapses with neighbouring cells”. Thus any attempt to shed light on brain function using...
Preprint
Two major technical challenges facing parallel nuclear magnetic resonance (NMR) spectroscopy, at the onset, include the need to achieve exceptional B0 homogeneity, and good inter-detector radiofrequency signal decoupling, and have remained technical obstacles that limit high throughput compound screening via NMR. In this contribution, we consider a...
Article
Glioblastoma multiforme is the most aggressive and invasive brain cancer consisting of genetically and phenotypically altering glial cells. It has massive heterogeneity due to its highly complex and dynamic microenvironment. Here, electrophysiological properties of U87 human glioma cell line were measured based on dielectrophoresis phenomenon to qu...
Article
Full-text available
When one thinks about electrodes, especially ones meant for humans, they typically think of some kind of metal. Whether on the skin or in the brain, metal electrodes are characteristically expensive, stiff, non-efficient in electron-ion transduction, and prone to toxic metal ion by-products during stimulation. In order to circumvent these disadvant...
Article
Full-text available
Carbon origami enables the fabrication of lightweight and mechanically stiff 3D complex architectures of carbonaceous materials, which have a high potential to impact a wide range of applications positively. The precursor materials and their inherent microstructure play a crucial role in determining the properties of carbon origami structures. Here...
Article
Full-text available
Engineered living materials (ELMs) are the most relevant contemporary revolution in materials science and engineering and aim to outperform current examples of ''smart,'' active, or multifunctional materials, enabling countless industrial and societal applications. The ''living'' materials facilitate unique properties, including autonomy , intellig...
Article
Shimming in the context of nuclear magnetic resonance aims to achieve a uniform magnetic field distribution, as perfect as possible, and is crucial for useful spectroscopy and imaging. Currently, shimming precedes most acquisition procedures in the laboratory, and this mostly semi-automatic procedure often needs to be repeated, which can be cumbers...
Chapter
A biosensor is an analytical device which recognizes a biological substance and converts the recognition into a measurable or readable signal. Since the first development in 1962 by Leland C. Clark, biosensors have been a hot topic in research communities. Biosensors have a huge impact on healthcare diagnostics, as well as on the monitoring and pha...
Article
Full-text available
Low-cost enzyme-free glucose sensors with partial flexibility adaptable for wearable Internet of Things devices that can be envisioned as personalized point-of-care devices were produced by electroplating copper on locally carbonized flexible meta-polyaramid (Nomex) sheets using laser radiation. Freestanding films were annealed in nitrogen and nitr...
Article
Full-text available
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 suppl...
Article
Full-text available
The metal–insulator–metal (MIM) waveguide, which can directly couple free space photons, acts as an important interface between conventional optics and subwavelength photoelectrons. The reason for the difficulty of this optical coupling is the mismatch between the large wave vector of the MIM plasmon mode and photons. With the increase in the wave...
Preprint
Full-text available
Engineered living materials (ELMs) are the most relevant contemporary revolution in materials science and engineering. These ELMs aim to outperform current examples of "smart", active or multifunctional materials, enabling countless industrial and societal applications. The "living" materials facilitate unique properties, including autonomy, intell...
Article
Full-text available
Carbon materials constitute a growing family of high-performance materials immersed in ongoing scientific technological revolutions. Their biochemical properties are interesting for a wide set of healthcare applications and their biomechanical performance, which can be modulated to mimic most human tissues, make them remarkable candidates for tissu...
Article
Full-text available
Laser-induced graphene (LIG) has emerged as an exciting material, which can be patterned on flexible substrates in an ambient condition using a fast and facile laser irradiation process and has been used for several applications. Popular low-power infrared laser cutter systems are facilitating the widespread use of LIG materials. Typically, a singl...
Article
Full-text available
Electromagnetic reciprocity has long been a staple in magnetic resonance (MR) radio-frequency development, offering geometrical insights and a figure of merit for various resonator designs. In a similar manner, we use magnetostatic reciprocity to compute manufacturable solutions of complex magnet geometries, by establishing a quantitative metric fo...
Preprint
Full-text available
Band selectivity to address specific resonances in a spectrum enables one to encode individual settings for diffusion experiments. In a single experiment, this could include different gradient strengths (enabling coverage of a larger range of diffusion constants), different diffusion delays, or different gradient directions (enabling anisotropic di...
Article
Full-text available
We integrate a compact, reconfigurable reaction cell featuring electrochemical functionality with high-resolution NMR spectroscopy. This system is used to monitor the activity of enzymes immobilized in chemically distinct layers within a multi-layered chitosan hydrogel assembly. We observed the parallel activities of urease, catalase, and glucose o...
Article
Full-text available
Compartmentalized chemical reactions at the microscale are important in biotechnology, yet monitoring the molecular content at these small scales is challenging. To address this challenge, we integrate a compact, reconfigurable reaction cell featuring electrochemical functionality with high‐resolution NMR spectroscopy. We demonstrate the operation...
Preprint
Full-text available
Electromagnetic reciprocity has long been a staple in MR radio-frequency development, offering geometrical insights and a figure of merit for various resonator designs. In a similar manner, we use magnetostatic reciprocity to compute manufacturable solutions of complex magnet geometries, by establishing a quantitative metric for the placement and s...
Article
Full-text available
The low frequency plateau in the frequency response of an untuned micro-resonator permits broadband radio-frequency reception, albeit at the expense of optimal signal-to-noise ratio for a particular nucleus. In this contribution we determine useful figures of merit for broadband micro-coils, and thereby explore the parametric design space towards a...
Article
Multiscale 3D carbon architectures are of particular interest in tissue engineering applications, as these structures may allow for three-dimensional cell colonization essential for tissue growth. In this work, carbon fiber/microlattice hybrid architectures are introduced as innovative multi-scale scaffolds for tissue engineering. The microlattice...
Article
Full-text available
Within microfluidic technologies, the centrifugal microfluidic “Lab-on-a-Disc” (LoaD) platform offers great potential for use at the PoC and in low-resource settings due to its robustness and the ability to port and miniaturize ‘wet bench’ laboratory protocols. We present the combination of ‘event-triggered dissolvable film valves’ with a centrifug...
Article
Full-text available
Nuclear magnetic resonance at low field strength is an insensitive spectroscopic technique, precluding portable applications with small sample volumes, such as needed for biomarker detection in body fluids. Here we report a compact double resonant chip stack system that implements in situ dynamic nuclear polarisation of a 130 nL sample volume, achi...
Article
Full-text available
A prototype of a wireless vacuum microsensor combining the Pirani principle and surface acoustic waves (SAW) with extended range and sensitivity was designed, modelled, manufactured and characterised under different conditions. The main components of the prototype are a sensing SAW chip, a heating coil and an interrogation antenna. All the componen...
Preprint
Compartmentalized chemical reactions at the microscale are interesting from many perspectives including (multi)functional surfaces and biotechnology. Monitoring the molecular content as a measure of functional performance at these small scales is challenging. As a means to address this challenge, we leverage microtechnology and biocompatible materi...
Preprint
Full-text available
Nuclear magnetic resonance at low field strength is an insensitive spectroscopic technique, precluding portable applications with small sample volumes, such as needed for biomarker detection in body fluids. Here we report a compact double resonant chip stack system that implements in situ dynamic nuclear polarisation of a 130 nL sample volume, achi...
Conference Paper
Full-text available
The control circuit for inductive levitation micro-actuators is developed in this research. The circuit performance and its electrical parameters are discussed. The developed control circuit was fabricated on a 4-layer PCB board having a size of 60 mm by 60 mm. It consists of a generator based on high-speed Flip-Flop components and a current amplif...
Article
A method for the fabrication of flexible electrical circuits on polyaramid substrates is presented based on laser-induced carbonization followed by copper electroplating. Locally carbonized flexible sheets of polyaramid (Nomex), by laser radiation, create rough and highly porous microstructures that show a higher degree of graphitization than therm...
Preprint
Full-text available
The low frequency plateau in the frequency response of an untuned micro-resonator permits broadband radio-frequency reception, albeit at the expense of optimal signal-to-noise ratio for a particular nucleus. In this contribution we determine a useful figure-of-merit for broadband microcoils, and thereby explore the parametric design space towards a...
Preprint
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 suppl...
Article
Full-text available
Improvements to the signal-to-noise ratio of magnetic resonance detection lead to a strong reduction in measurement time, yet as a sole optimization goal for resonator design, it would be an oversimplification of the problem at hand. Multiple constraints, for example for field homogeneity and sample shape, suggest the use of numerical optimization...
Article
This work presents a novel approach in synthesizing copper (Cu)/carbon composite materials by electrodeposition of the biopolymer chitosan, a renewable carbon precursor, on a copper anode, followed by pyrolysis of the electrodeposited chitosan gel. The amount of copper in the Cu/carbon composite material can be controlled by modifying the pH of the...
Article
Full-text available
Successful development of a micro-total-analysis system (µTAS, lab-on-a-chip) is strictly related to the degree of miniaturization, integration, autonomy, sensitivity, selectivity, and repeatability of its detector. Fluorescence sensing is an optical detection method used for a large variety of biological and chemical assays, and its full integrati...
Preprint
Full-text available
Improvements to the signal-to-noise ratio of magnetic resonance detection leads to a strong reduction in measurement time, yet as a sole optimization goal for resonator design it would be an oversimplification of the problem at hand. Multiple constraints, for example for field homogeneity, and sample shape, suggests the use of numerical optimizatio...
Article
Full-text available
Interventional magnetic resonance imaging (iMRI) using MR-catheters has been explored during the past decade because of its potential impact on the field of minimally invasive medical procedures, especially applied to vascular diseases. Tracking the catheter's tip during an iMRI procedure using active electronic components has mayor benefits but st...
Article
Combining microfluidic devices with nuclear magnetic resonance (NMR) has the potential of unlocking their vast sample handling and processing operation space for use with the powerful analytics provided by NMR. One particularly challenging class of integrated functional elements from the perspective of NMR are conductive structures. Metallic electr...
Article
Full-text available
Formaldehyde (HCHO), a chemical compound used in the fabrication process of a broad range of household products, is present indoors as an airborne pollutant due to its high volatility caused by its low boiling point ( T = − 19 °C). Miniaturization of analytical systems towards palm-held devices has the potential to provide more efficient and more s...
Article
Full-text available
We introduce a low-complexity, low-cost, yet sufficiently accurate automatic tune and match system for NMR and MRI applications. The ArduiTaM builds upon an Arduino Uno embedded system that drives a commercial frequency synthesiser chip to perform a frequency sweep around the Larmor frequency. The generated low-power signal is fed to the NMR coil,...
Article
Full-text available
An analysis of the detailed operation for the tube element is proposed for an orifice pulse tube cryocooler. This is achieved through phasor analysis using basic thermodynamic relations to estimate the approximated cooling power associated with this machine. Moreover, the effect of the phase shift angle is illustrated by forming an analogy between...
Article
This paper presents topology optimization on general two-dimensional manifolds for phenomena described by second-order partial differential equations, where the material interpolation is implemented by using the material distribution method. When a physical field is defined on a two-dimensional manifold, the material interpolation is implemented on...
Article
Full-text available
This paper presents the topology optimization of hierarchical microtextures for wetting behavior in the Cassie-Baxter mode, considering a structural unit of the hierarchical microtexture composed of base and secondary structures. The geometrical configuration of the considered structural unit can be described as a fiber bundle composed of an extern...
Article
Full-text available
Mesial temporal lobe epilepsy (MTLE) is the most common type of focal epilepsy. It is frequently associated with abnormal MRI findings, which are caused by underlying cellular, structural, and chemical changes at the micro-scale. In the current study, it is investigated to which extent these alterations correspond to imaging features detected by hi...
Preprint
Full-text available
Abstract. We introduce a low complexity, low cost, yet sufficiently accurate automatic tune and match system for NMR and MRI applications. The ArduiTaM builds upon an Arduino Uno embedded system that drives a commercial frequency synthesizer chip to perform a frequency sweep around the Larmor frequency. The generated low power signal is fed to the...
Article
Full-text available
Edible rice paper wrapper is found to be an interesting precursor of a porous and light-weight carbon material. During pyrolysis, material samples show significant differences in length change, displaying typical 20–25% shrinking in the in-plane directions, and strongly expanding (up to 500%) across their out-of-plane direction. This results in a t...
Preprint
Full-text available
Combining microfluidic devices with nuclear magnetic resonance (NMR) has the potential of unlocking their vast sample handling and processing operation space for use with the powerful analytics provided by NMR. One particularly challenging class of integrated functional elements from the perspective of NMR are conductive structures. Metallic electr...