Dario Mager | Karlsruhe Institute of Technology (KIT) (original) (raw)
Papers by Dario Mager
We review the utility of centrifugal microfluidic technologies applied to point-of-care diagnosis... more We review the utility of centrifugal microfluidic technologies applied to point-of-care diagnosis in extremely under-resourced environments. The various challenges faced in these settings are showcased, using areas in India and Africa as examples. Measures for the ability of integrated devices to effectively address point-of-care challenges are highlighted, and centrifugal, often termed CD-based microfluidic technologies, technologies are presented as a promising platform to address these challenges. We describe the advantages of centrifugal liquid handling, as well as the ability of a standard CD player to perform a number of common laboratory tests, fulfilling the role of an integrated lab-on-a-CD. Innovative centrifugal approaches for point-of-care in extremely resource-poor settings are highlighted, including sensing and detection strategies, smart power sources and biomimetic inspiration for environmental control. The evolution of centrifugal microfluidics, along with examples of commercial and advanced prototype centrifugal microfluidic systems, is presented, illustrating the success of deployment at the point-of-care. A close fit of emerging centrifugal systems to address a critical panel of tests for under-resourced clinic settings, formulated by medical experts, is demonstrated. This emphasizes the potential of centrifugal microfluidic technologies to be applied effectively to extremely challenging point-of-care scenarios and in playing a role in improving primary care in resource-limited settings across the developing world.
We review the utility of centrifugal microfluidic technologies applied to point-of-care diagnosis... more We review the utility of centrifugal microfluidic technologies applied to point-of-care diagnosis in extremely under-resourced environments. The various challenges faced in these settings are showcased, using areas in India and Africa as examples. Measures for the ability of integrated devices to effectively address point-of-care challenges are highlighted, and centrifugal, often termed CD-based microfluidic technologies, technologies are presented as a promising platform to address these challenges. We describe the advantages of centrifugal liquid handling, as well as the ability of a standard CD player to perform a number of common laboratory tests, fulfilling the role of an integrated lab-on-a-CD. Innovative centrifugal approaches for point-of-care in extremely resource-poor settings are highlighted, including sensing and detection strategies, smart power sources and biomimetic inspiration for environmental control. The evolution of centrifugal microfluidics, along with examples of commercial and advanced prototype centrifugal microfluidic systems, is presented, illustrating the success of deployment at the point-of-care. A
close fit of emerging centrifugal systems to address a critical panel of tests for under-resourced clinic settings, formulated by medical experts, is demonstrated. This emphasizes the potential of centrifugal microfluidic technologies to be applied effectively to extremely challenging point-of-care scenarios and in playing a role in improving primary care in resource-limited settings across the developing world.
PloS one, 2016
We present a completely revised generation of a modular micro-NMR detector, featuring an active s... more We present a completely revised generation of a modular micro-NMR detector, featuring an active sample volume of ∼ 100 nL, and an improvement of 87% in probe efficiency. The detector is capable of rapidly screening different samples using exchangeable, application-specific, MEMS-fabricated, microfluidic sample containers. In contrast to our previous design, the sample holder chips can be simply sealed with adhesive tape, with excellent adhesion due to the smooth surfaces surrounding the fluidic ports, and so withstand pressures of ∼2.5 bar, while simultaneously enabling high spectral resolution up to 0.62 Hz for H2O, due to its optimised geometry. We have additionally reworked the coil design and fabrication processes, replacing liquid photoresists by dry film stock, whose final thickness does not depend on accurate volume dispensing or precise levelling during curing. We further introduced mechanical alignment structures to avoid time-intensive optical alignment of the chip stacks ...
18th IEEE International Conference on Micro Electro Mechanical Systems, 2005. MEMS 2005., 2005
This paper reports a systematic analysis of the geometry dependent sensitivity of planar piezores... more This paper reports a systematic analysis of the geometry dependent sensitivity of planar piezoresistive stress sensors based on the shear piezoresistance effect, also termed pseudo-Hall effect. The analyzed geometry parameters are: (i) the shape of the device active area, (ii) its aspect ratio, and (iii) the location and size of input and output contacts. Further, the influence of insulating holes
The combination of magnetic resonance (MR)-based investigations, as a non-invasive and nondestruc... more The combination of magnetic resonance (MR)-based investigations, as a non-invasive and nondestructive technique, and automated tracking of biological sample movement (e.g., free moving microorganisms) provides a unique opportunity to link chemically specific spectroscopic information to morphological and behavioural data from a complete organism under normal physiological conditions in vivo.
Journal of Micromechanics and Microengineering, 2015
ABSTRACT We present a new self-aligned, mask-free micro-fabrication method with which to form thi... more ABSTRACT We present a new self-aligned, mask-free micro-fabrication method with which to form thick-layered conductive metal micro-structures inside electroplating moulds. Seed layer patterning for electroplating was performed by ink-jet printing using a silver nano-particle ink deposited on SU-8 or Ordyl SY permanent resist. The silver ink contact angle on SU-8 was adjusted by oxygen plasma followed by a hard bake. Besides functioning as a seed layer, the printed structures further served as a shadow mask during patterning of electroplating moulds into negative photoresist. The printed silver tracks remained in strong adhesion to the substrate when exposed to the acidic chemistry of the electroplating bath. To demonstrate the process, we manufactured rectangular, low-resistivity planar micro-coils for use in magnetic resonance microscopy. MRI images of a spring onion with an in-plane resolution down to 10 µm × 10 µm were acquired using a micro-coil on an 11.7 T MRI scanner.
Mechatronics, 2015
ABSTRACT
Lab Chip, 2015
We present a design for wireless power transfer, via inductively coupled coils, to a spinning dis... more We present a design for wireless power transfer, via inductively coupled coils, to a spinning disk. The rectified and stabilised power feeds an Arduino-compatible microcontroller (μC) on the disc, which in turn drives and monitors various sensors and actuators. The platform, which has been conceived to flexibly prototype such systems, demonstrates the feasibility of a wireless power supply and the use of a μC circuit, for example for Lab-on-a-disk applications, thereby eliminating the need for cumbersome slip rings or batteries, and adding a cogent and new degree of freedom to the setup. The large number of sensors and actuators included demonstrate that a wide range of physical parameters can be easily monitored and altered. All devices are connected to the μC via an I(2)C bus, therefore can be easily exchanged or augmented by other devices in order to perform a specific task on the disk. The wireless power supply takes up little additional physical space and should work in conjunction with most existing Lab-on-a-disk platforms as a straightforward add-on, since it does not require modification of the rotation axis and can be readily adapted to specific geometrical requirements.
Sensors and Actuators A: Physical, 2006
The dependence of the sensitivity of planar piezoresistive stress sensors on geometry is systemat... more The dependence of the sensitivity of planar piezoresistive stress sensors on geometry is systematically analyzed. The sensors in this paper are based on the shear piezoresistance effect, also termed pseudo-Hall effect. The analyzed geometry parameters are: (i) the shape of the device active area, (ii) its aspect ratio and (iii) the location and size of input and output contacts. Further, the influence of non-conducting islands in the active device area was investigated. General design rules for the design of piezoresistive stress sensors with improved sensitivity were extracted. These results were obtained using a simulation approach combining affine mapping with the finite element method. The simulation program was tested by comparing simulation results with experimental data obtained from stress sensors fabricated in CMOS technology. The differences between simulated and measured results were between 1.2 and 3.3%. Novel optimized sensor geometries with non-conducting islands show simulated and measured sensitivities greatly improved by factors up to 2.30 and 2.39, respectively. Further, the new sensors with non-conducting islands are put in perspective with classical Wheatstone bridges.
Procedia Technology, 2014
ABSTRACT
We review the utility of centrifugal microfluidic technologies applied to point-of-care diagnosis... more We review the utility of centrifugal microfluidic technologies applied to point-of-care diagnosis in extremely under-resourced environments. The various challenges faced in these settings are showcased, using areas in India and Africa as examples. Measures for the ability of integrated devices to effectively address point-of-care challenges are highlighted, and centrifugal, often termed CD-based microfluidic technologies, technologies are presented as a promising platform to address these challenges. We describe the advantages of centrifugal liquid handling, as well as the ability of a standard CD player to perform a number of common laboratory tests, fulfilling the role of an integrated lab-on-a-CD. Innovative centrifugal approaches for point-of-care in extremely resource-poor settings are highlighted, including sensing and detection strategies, smart power sources and biomimetic inspiration for environmental control. The evolution of centrifugal microfluidics, along with examples of commercial and advanced prototype centrifugal microfluidic systems, is presented, illustrating the success of deployment at the point-of-care. A close fit of emerging centrifugal systems to address a critical panel of tests for under-resourced clinic settings, formulated by medical experts, is demonstrated. This emphasizes the potential of centrifugal microfluidic technologies to be applied effectively to extremely challenging point-of-care scenarios and in playing a role in improving primary care in resource-limited settings across the developing world.
We review the utility of centrifugal microfluidic technologies applied to point-of-care diagnosis... more We review the utility of centrifugal microfluidic technologies applied to point-of-care diagnosis in extremely under-resourced environments. The various challenges faced in these settings are showcased, using areas in India and Africa as examples. Measures for the ability of integrated devices to effectively address point-of-care challenges are highlighted, and centrifugal, often termed CD-based microfluidic technologies, technologies are presented as a promising platform to address these challenges. We describe the advantages of centrifugal liquid handling, as well as the ability of a standard CD player to perform a number of common laboratory tests, fulfilling the role of an integrated lab-on-a-CD. Innovative centrifugal approaches for point-of-care in extremely resource-poor settings are highlighted, including sensing and detection strategies, smart power sources and biomimetic inspiration for environmental control. The evolution of centrifugal microfluidics, along with examples of commercial and advanced prototype centrifugal microfluidic systems, is presented, illustrating the success of deployment at the point-of-care. A
close fit of emerging centrifugal systems to address a critical panel of tests for under-resourced clinic settings, formulated by medical experts, is demonstrated. This emphasizes the potential of centrifugal microfluidic technologies to be applied effectively to extremely challenging point-of-care scenarios and in playing a role in improving primary care in resource-limited settings across the developing world.
PloS one, 2016
We present a completely revised generation of a modular micro-NMR detector, featuring an active s... more We present a completely revised generation of a modular micro-NMR detector, featuring an active sample volume of ∼ 100 nL, and an improvement of 87% in probe efficiency. The detector is capable of rapidly screening different samples using exchangeable, application-specific, MEMS-fabricated, microfluidic sample containers. In contrast to our previous design, the sample holder chips can be simply sealed with adhesive tape, with excellent adhesion due to the smooth surfaces surrounding the fluidic ports, and so withstand pressures of ∼2.5 bar, while simultaneously enabling high spectral resolution up to 0.62 Hz for H2O, due to its optimised geometry. We have additionally reworked the coil design and fabrication processes, replacing liquid photoresists by dry film stock, whose final thickness does not depend on accurate volume dispensing or precise levelling during curing. We further introduced mechanical alignment structures to avoid time-intensive optical alignment of the chip stacks ...
18th IEEE International Conference on Micro Electro Mechanical Systems, 2005. MEMS 2005., 2005
This paper reports a systematic analysis of the geometry dependent sensitivity of planar piezores... more This paper reports a systematic analysis of the geometry dependent sensitivity of planar piezoresistive stress sensors based on the shear piezoresistance effect, also termed pseudo-Hall effect. The analyzed geometry parameters are: (i) the shape of the device active area, (ii) its aspect ratio, and (iii) the location and size of input and output contacts. Further, the influence of insulating holes
The combination of magnetic resonance (MR)-based investigations, as a non-invasive and nondestruc... more The combination of magnetic resonance (MR)-based investigations, as a non-invasive and nondestructive technique, and automated tracking of biological sample movement (e.g., free moving microorganisms) provides a unique opportunity to link chemically specific spectroscopic information to morphological and behavioural data from a complete organism under normal physiological conditions in vivo.
Journal of Micromechanics and Microengineering, 2015
ABSTRACT We present a new self-aligned, mask-free micro-fabrication method with which to form thi... more ABSTRACT We present a new self-aligned, mask-free micro-fabrication method with which to form thick-layered conductive metal micro-structures inside electroplating moulds. Seed layer patterning for electroplating was performed by ink-jet printing using a silver nano-particle ink deposited on SU-8 or Ordyl SY permanent resist. The silver ink contact angle on SU-8 was adjusted by oxygen plasma followed by a hard bake. Besides functioning as a seed layer, the printed structures further served as a shadow mask during patterning of electroplating moulds into negative photoresist. The printed silver tracks remained in strong adhesion to the substrate when exposed to the acidic chemistry of the electroplating bath. To demonstrate the process, we manufactured rectangular, low-resistivity planar micro-coils for use in magnetic resonance microscopy. MRI images of a spring onion with an in-plane resolution down to 10 µm × 10 µm were acquired using a micro-coil on an 11.7 T MRI scanner.
Mechatronics, 2015
ABSTRACT
Lab Chip, 2015
We present a design for wireless power transfer, via inductively coupled coils, to a spinning dis... more We present a design for wireless power transfer, via inductively coupled coils, to a spinning disk. The rectified and stabilised power feeds an Arduino-compatible microcontroller (μC) on the disc, which in turn drives and monitors various sensors and actuators. The platform, which has been conceived to flexibly prototype such systems, demonstrates the feasibility of a wireless power supply and the use of a μC circuit, for example for Lab-on-a-disk applications, thereby eliminating the need for cumbersome slip rings or batteries, and adding a cogent and new degree of freedom to the setup. The large number of sensors and actuators included demonstrate that a wide range of physical parameters can be easily monitored and altered. All devices are connected to the μC via an I(2)C bus, therefore can be easily exchanged or augmented by other devices in order to perform a specific task on the disk. The wireless power supply takes up little additional physical space and should work in conjunction with most existing Lab-on-a-disk platforms as a straightforward add-on, since it does not require modification of the rotation axis and can be readily adapted to specific geometrical requirements.
Sensors and Actuators A: Physical, 2006
The dependence of the sensitivity of planar piezoresistive stress sensors on geometry is systemat... more The dependence of the sensitivity of planar piezoresistive stress sensors on geometry is systematically analyzed. The sensors in this paper are based on the shear piezoresistance effect, also termed pseudo-Hall effect. The analyzed geometry parameters are: (i) the shape of the device active area, (ii) its aspect ratio and (iii) the location and size of input and output contacts. Further, the influence of non-conducting islands in the active device area was investigated. General design rules for the design of piezoresistive stress sensors with improved sensitivity were extracted. These results were obtained using a simulation approach combining affine mapping with the finite element method. The simulation program was tested by comparing simulation results with experimental data obtained from stress sensors fabricated in CMOS technology. The differences between simulated and measured results were between 1.2 and 3.3%. Novel optimized sensor geometries with non-conducting islands show simulated and measured sensitivities greatly improved by factors up to 2.30 and 2.39, respectively. Further, the new sensors with non-conducting islands are put in perspective with classical Wheatstone bridges.
Procedia Technology, 2014
ABSTRACT