Stefan Harazim
Research interests
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InterestsThin Film Deposition, Microfluidic Engineering, Microfluidics, Sensors, rolled-up nanotech
Publications
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6.34Impact points
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6.34Impact points
Lab-in-a-tube: ultracompact components for on-chip capture and detection of individual micro-/nanoorganisms.
Lab on a chip. 03/2012;
A review of present and future on-chip rolled-up devices, which can be used to develop lab-in-a-tube total analysis systems, is presented. Lab-in-a-tube is the integration of numerous rolled-up components into a single device constituting a microsystem of hundreds/thousands of independent units on a... [more] A review of present and future on-chip rolled-up devices, which can be used to develop lab-in-a-tube total analysis systems, is presented. Lab-in-a-tube is the integration of numerous rolled-up components into a single device constituting a microsystem of hundreds/thousands of independent units on a chip, each individually capable of sorting, detecting and analyzing singular organisms. Such a system allows for a scale-down of biosensing systems, while at the same time increasing the data collection through a large, smart array of individual biosensors. A close look at these ultracompact components which have been developed over the past decade is given. Methods for the capture of biomaterial are laid out and progress of cell culturing in three-dimensional scaffolding is detailed. Rolled-up optical sensors based on photoluminescence, optomechanics, optofluidics and metamaterials are presented. Magnetic sensors are introduced as well as electrical components including heating, energy storage and resistor devices.
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7.49Impact points
Self-propelled nanotools.
ACS nano. 02/2012; 6(2):1751-6.
We describe nanoscale tools in the form of autonomous and remotely guided catalytically self-propelled InGaAs/GaAs/(Cr)Pt tubes. These rolled-up tubes with diameters in the range of 280-600 nm move in hydrogen peroxide solutions with speeds as high as 180 μm s(-1). The effective transfer of chemical... [more] We describe nanoscale tools in the form of autonomous and remotely guided catalytically self-propelled InGaAs/GaAs/(Cr)Pt tubes. These rolled-up tubes with diameters in the range of 280-600 nm move in hydrogen peroxide solutions with speeds as high as 180 μm s(-1). The effective transfer of chemical energy to translational motion has allowed these tubes to perform useful tasks such as transport of cargo. Furthermore, we observed that, while cylindrically rolled-up tubes move in a straight line, asymmetrically rolled-up tubes move in a corkscrew-like trajectory, allowing these tubes to drill and embed themselves into biomaterials. Our observations suggest that shape and asymmetry can be utilized to direct the motion of catalytic nanotubes and enable mechanized functions at the nanoscale.
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3.86Impact points
The smallest man-made jet engine.
Chemical record (New York, N.Y.). 09/2011; 11(6):367-70.
The design of catalytic engines powered by chemical fuels is an exciting and emerging field in multidisciplinary scientific communities. Recent progress in nanotechnology has enabled scientists to shrink the size of macroengines down to microscopic, but yet powerful, engines. Since a couple of years... [more] The design of catalytic engines powered by chemical fuels is an exciting and emerging field in multidisciplinary scientific communities. Recent progress in nanotechnology has enabled scientists to shrink the size of macroengines down to microscopic, but yet powerful, engines. Since a couple of years ago, we have reported our progress towards the control and application of catalytic microtubular engines powered by the breakdown of hydrogen peroxide fuel which produces a thrust of oxygen bubbles. Efforts were undertaken in our group to prove whether the fabrication of nanoscale jets is possible. Indeed, the smallest jet engine (600 nm in diameter and 1 picogram of weight) was synthesized based on heteroepitaxially grown layers. These nanojets are able to self-propel in hydrogen peroxide solutions and are promising for the realisation of multiple tasks.
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8.58Impact points
Microbots swimming in the flowing streams of microfluidic channels.
Journal of the American Chemical Society. 02/2011; 133(4):701-3.
We describe the motion of self-propelled catalytic Ti/Fe/Pt rolled-up microtubes (microbots) in the microchannels of a microfluidics system. Their motion is precisely controlled by a small magnetic field, and the transport of multiple spherical microparticles into desired locations is achieved. The ... [more] We describe the motion of self-propelled catalytic Ti/Fe/Pt rolled-up microtubes (microbots) in the microchannels of a microfluidics system. Their motion is precisely controlled by a small magnetic field, and the transport of multiple spherical microparticles into desired locations is achieved. The microbots are powerful enough to propel themselves against flowing streams. The integration of “smart and powerful” microbots into microchip systems can lead to multiple lab-on-a-chip functions such as separation of cells and biosensing.
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4.80Impact points
Fabrication and applications of large arrays of multifunctional rolled-up SiO/SiO2 microtubes
Journal of Materials Chemistry. 01/2011;
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8.58Impact points
Microbots swimming in the flowing streams of microfluidic channels
Journal of the American Chemical Society. 01/2011; 133:701.
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3.86Impact points
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2.89Impact points
Integrated sensitive on-chip ion field effect transistors based on wrinkled InGaAs nanomembranes
Nanoscale Research Letters. 01/2011; 6:215.
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7.49Impact points
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2.89Impact points
Integrated sensitive on-chip ion field effect transistors based on wrinkled InGaAs nanomembranes.
Nanoscale research letters. 01/2011; 6(1):215.
ABSTRACT: Self-organized wrinkling of pre-strained nanomembranes into nanochannels is used to fabricate a fully integrated nanofluidic device for the development of ion field effect transistors (IFETs). Constrained by the structure and shape of the membrane, the deterministic wrinkling process leads... [more] ABSTRACT: Self-organized wrinkling of pre-strained nanomembranes into nanochannels is used to fabricate a fully integrated nanofluidic device for the development of ion field effect transistors (IFETs). Constrained by the structure and shape of the membrane, the deterministic wrinkling process leads to a versatile variation of channel types such as straight two-way channels, three-way branched channels, or even four-way intersection channels. The fabrication of straight channels is well controllable and offers the opportunity to integrate multiple IFET devices into a single chip. Thus, several IFETs are fabricated on a single chip using a III-V semiconductor substrate to control the ion separation and to measure the ion current of a diluted potassium chloride electrolyte solution.
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8.38Impact points
Local-illuminated ultrathin silicon nanomembranes with photovoltaic effect and negative transconductance.
Advanced materials (Deerfield Beach, Fla.). 09/2010; 22(33):3667-71.
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8.38Impact points
Local-illuminated ultrathin silicon nanomembranes with photovoltaic effect and negative transconductance
Advanced Materials. 01/2010; 22:3667.
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12.22Impact points
Principles and applications of micro and nanoscale wrinkles
Materials Science and Engineering R Reports. 01/2010; 70:209.
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9.99Impact points
Giant Persistent Photoconductivity in Rough Silicon Nanomembranes.
Nano letters. 08/2009;
This paper reports the observation of giant persistent photoconductivity from rough Si nanomembranes. When exposed to light, the current in p-type Si nanomembranes is enhanced by roughly 3 orders of magnitude in comparison with that in the dark and can persist for days at a high conductive state aft... [more] This paper reports the observation of giant persistent photoconductivity from rough Si nanomembranes. When exposed to light, the current in p-type Si nanomembranes is enhanced by roughly 3 orders of magnitude in comparison with that in the dark and can persist for days at a high conductive state after the light is switched off. An applied gate voltage can tune the persistent photocurrent and accelerate the response to light. By analyzing the band structure of the devices and the surfaces through various coatings, we attribute the observed effect to hole-localized regions in Si nanomembranes due to the rough surfaces, where light can activate the confined holes.
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9.99Impact points
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Principles and applications of micro and nanoscale wrinkles
Materials Science and Engineering: R: Reports.
In this review, we summarize recent and interesting applications of micro and nanoscale wrinkles. Fluidic studies are comprehensively highlighted for various wrinkled nanochannels. Wrinkling as a mechanical characterization tool is also explained. As a new feature, wrinkles are employed to modify st... [more] In this review, we summarize recent and interesting applications of micro and nanoscale wrinkles. Fluidic studies are comprehensively highlighted for various wrinkled nanochannels. Wrinkling as a mechanical characterization tool is also explained. As a new feature, wrinkles are employed to modify structures or physical properties of nanomaterials. It is promising to apply wrinkling for strain-engineering of graphene. We believe that wrinkling offers entirely new research perspectives in micro and nanotechnologies as well as in material sciences and engineering.
Following (7)
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Mohammad-Reza Behi
Technische Universiteit Eindhoven -
Adriana Remes
Technische Universiteit Delft -
Jiahao Wu
Louisiana State University -
Liza Rassaei
Universiteit Twente -
Elodie Sollier
UCLA
