Micro-Engines
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"Starting" and "stopping" microjet enginesThe control over the autonomous motion of artificial nano/micromachines is essential for real biomedical and nanotechnological applications. Consequently, a complete nanomachine should be able to be turned on and off at will. We report the tuning of the propulsion power of catalytic microjets through illumination of a solution by a white-light source. We show that light suppresses the generation of microbubbles, stopping the engines if they are fixed-to or self-propelled above a platinum-patterned surface. The microjets are reactivated by dimming the light source that illuminates the fuel solution.A. A. Solovev et al., Angewandte Chemie International Edition DOI: 10.1002/anie.201102096 (2011) URL PDF | |||
Superfast motion of catalytic microjet engines at physiological temperatureWe reduced the toxicity of the fuel used to self-propel artificial nanomachines. At physiological temperatures, i.e. 37°C, only very small amounts of H2O2 as fuel is needed to propel the microjets. Under those conditions, Fibroblast cells are viable for more than 1 hour which is highly important for the not-too-distant use of artificial nanomachines in biomedical applications. In addition, at 5% H2O2, the microjets acquire superfast speeds reaching 10 mm sec-1. The dynamics of motion is altered while increasing the speed, i.e. the motion deviates from the linear to curvilinear trajectories which has been theoretically modelled.S. Sanchez et al., Journal of the American Chemical Society 133, 14860 (2011) URL PDF This work was highlighted in: New Scientist, 2832 (2011) (Oct 2, 2011) URL | |||
Towards remotely controlled intelligent microrobotsIn this tutorial review we describe recent progress on catalytic microtubular engines fabricated by rolled-up nanotech. The control over speed, directionality and interactions of the microengines to perform tasks such as cargo transportation is also discussed. Since rolled-up nanotech on polymers can easily integrate almost any type of inorganic material, huge potential and advanced performance such as high speed, cargo delivery, motion control, and dynamic assembly are foreseen-ultimately promising a practical way to construct versatile and intelligent catalytic tubular microrobots.Y. F. Mei et al., Chemical Society Reviews 40, 2109 (2011) URL PDF This work was highlighted in: derStandard.at (March 8, 2011) URL LiLipuz (March 9, 2011) URL Blick.ch (March 9, 2011) URL | |||
Guinness World Record® for "Smallest Man-Made Jet Engine""The smallest man-made jet engine measures just 600nm across and weighs 1 picogram. It was produced by Alex A. Solovev, Samuel Sanchez, Yongfeng Mei and Oliver G. Schmidt at the Leibniz Institute for Solid State and Materials Research (IFW Dresden)."This is the text of the official certificate issued by Guinness World Records® beginning of this year (see left side for scanned original). This achievement was highlighted in: Pro-Physik.de (March 8, 2011) URL Die Welt (March 8, 2011) URL Scinexx (March 9, 2011) URL Nanowerk (March 9, 2011) URL | |||
Microbots swimming in the flowing streams of microfluidic channelsThe motion of artificial catalytic nanomachines is commonly studied in free bulk solution, which differs significantly from the stream-like channel networks existing in the human body. Here, we demonstrate that catalytic microbots can self-propel in the microchannels of a microfluidics system and transport multiple spherical microparticles into desired locations. We also show for the first time that artificial micromachines can easily swim against strong flowing streams.The integration of “smart and powerful” microbots with microchips will lead to plentiful functions in lab-on-a-chip devices including e.g. efficient and convenient drug or cell separation.S. Sanchez et al., Journal of The American Chemical Society 133, 701 (2011) URL PDF | |||
Transport of animal cell material by catalytic microbotsAnimal cells can be transported within a fluid in a controllable manner by using artificial microbots. The Ti/Fe/Pt rolled-up catalytic microjet engine (microbot) is guided towards a specific cell, which is moved to a desired location where it is released. The direction of the microbots is easily steered by using an external small magnetic field. This work paves the way to future biomedical applications of artificial micromachines such as curing unhealthy cells or separation of cancer cells.S. Sanchez et al., Chemical Communications 47, 698 (2011) URL PDF | |||
Collective behaviour of artifcial autonomous systemsArtificial autonomous systems act as catalytic water striders at the air–liquid interface of hydrogen peroxide solution. Such systems, buoyed by oxygen bubbles, self-propel at the fuel surface by the bubble recoiling mechanism and dynamically self-assemble into patterns due to the meniscus-climbing effect. Artificial systems like these are ideally suited to study the collective behaviour of a large number of individuals, where repelling engine power competes against attractive surface tension. Our results give way to many new approaches to sense environment with swarms of micro-/nanoengineered microtube robots.A. A. Solovev et al., Advanced Materials 22, 4340 (2010) URL PDF This work was highlighted in: Nanowerk.com (Sep 30, 2010) URL MaterialsViews (Nov 10, 2010) URL | |||
Highly efficient locomotion of hybrid biocatalytic microenginesWe have designed a novel hybrid biocatalytic microengine. The engine is based on a catalytic enzyme, catalase, specifically bounded to self-assembled monolayers covering the inside wall of an inorganic rolled-up microtube. This novel approach leads to faster, more powerful, and more efficient microengines requiring much lower concentrations of peroxide fuel. The engine's speed and direction is dynamically controlled by the friction of bubbles attached to the outside wall of the microtube. Our work presents a major step towards engineering micro-/nanorobots which run on biocompatible fuels and which - one day - might well sense their environment biochemically.S. Sanchez et al., Journal of The American Chemical Society 132, 13144 (2010) URL PDF This work was highlighted in: RSC Chemistry World (July 29, 2010) URL Nanowerk.com (Aug 3, 2010) URL ChemViews Magazine (Aug 11, 2010) URL | |||
Magnetic control of tubular catalytic microbotsWe have demonstrated the magnetic control of self-propelled catalytic Ti/Fe/Pt rolled-up microtubes (microbots). The microbots move by ejecting microbubbles, which are produced by a platinum catalytic decomposition of hydrogen peroxide into oxygen and water. The particularly easy control over the movement of the microbots by changing the direction of the magnetic field during motion helps to accurately load and deliver cargo at desired places in a fluid. Our microbots show a high propulsion power that allows the selective transport of up to 60 polystyrene microparticles and several thin metallic nanoplates. Our microbots represent an exciting artificial species to be employed for applications such as controllable drug-delivery and cleaning tasks.A. A. Solovev et al., Advanced Functional Materials 20, 2430 (2010) URL PDF This work was highlighted in: Nanowerk.com (Aug 3, 2010) URL | |||
 | Microtubular jet enginesWe have strain-engineered microtubes traveling as self-propelled catalytic microjet engines along various trajectories with speeds up to ≈ 2 mm s-1 (approximately 50 body lengths per second). The motion of the microjets is generated by gas bubbles thrust out of one opening of the tube. The trajectories of various geometries can be traced by long microbubble tails. A magnetic layer is integrated into the wall of the microjet engine, which allows easy control over the direction of motion by applying external magnetic fields.A. A. Solovev et al., Small 5, 1688 (2009) URL PDF | ||
 | Ferngesteuerte MikroraketenWir haben winzige Mikroraketen hergestellt, die sich durch ein Magnetfeld fernsteuern lassen. Die Herstellung der Mikroraketen erfolgt durch hauchdünne Schichtsysteme, die sich auf einem Trägersubstrat von selbst zu Mikroröhrchen aufrollen. Nach dem Ablösen der Röhrchen von dem Substrat erzeugen die chemisch aktiven Innenwände eine katalytische Reaktion in einer Flüssigkeit. Die Reaktion führt zur Bildung von Sauerstoffblasen, die aus den Röhrchen ausgestoßen werden, und so für den Vortrieb der Mikrorakete sorgen. Da das aufgerollte Schichtsystem magnetische Materialien enthält, können die Mikroraketen durch ein Magnetfeld ferngesteuert werden.Oliver G. Schmidt, Spektrum der Wissenschaft, S.16, Juli 2009 URL Oliver G. Schmidt, Welt der Physik 16.05.2009 URL | ||
Strain engineered micro-/nanotubes on polymersA generic approach has been developed to engineer tubular micro-/nanostructures out of many different materials with tunable diameters and lengths by precisely releasing and rolling up functional nanomembranes on polymers. The technology spans across different scientific fields ranging from photonics to biophysics and we demonstrate optical ring resonators, magneto-fluidic sensors, remotely controlled microjets and 2D confined channels for cell growth guiding.Y. F. Mei et al., Advanced Materials 20, 4085 (2008) URL PDF This work was highlighted in: P.M. Magazine (February 17, 2009) URL Frankfurter Allgemeine Zeitung (November 11, 2008) URL Nanowerk (October 20, 2008) URL Pro Physik (October 20, 2008) URL Bild (August 27, 2008) URL
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