Institute for Integrative Nanosciences (IIN)
The Institute for Integrative Nanosciences IIN was founded on 1st March 2007. About 70-80 scientists and staff members originating from more than ten different nations carry out research both at our main location in Dresden but also at our research site in Chemnitz which was founded two years later in 2009. Research activities at the IIN cover a wealth of modern topics in the Nanosciences ranging from flexible electronics to micro-/nanoscale robotics.
The most important inventions from the IIN include flexible and printable magnetoelectronic devices, the smallest men-made jet engines, self-propelled nanotools, strain tunable single photon devices, lab-in-a-tube systems and ultra-compact self-wound batteries.
Most recent highlights:
All-electric access to the magnetic-field-invariant magnetization of antiferromagnets
Antiferromagnets have the potential to revolutionize spintronics due to their inherently magnetic-field stable magnetic order. To reveal the rich physics of these materials, we introduce spinning-current anomalous Hall magnetometry opening the scope for magnetic phenomena that can go amiss otherwise. This provides new insights into the physics of the fundamentally-appealing magnetoelectric Cr2O3 and application-relevant IrMn antiferromagnets. The work was carried out in collaboration with the HZB, BESSY II.
This work was chosen as PRL Editors' suggestion.
Neural stem cell migration under spatial confinement
We exploit the well-defined geometry and optical transparency of glass microtubes to investigate how scaffold dimensionality and cell confinement influence the spontaneous migration of neural stem cells. These findings advance our comprehension of how the extracellular environment can control cell behavior, which is of major importance in tissue engineering and biomaterial-assisted cell delivery applications.
Monolithic integration of vertical optical ring resonators
We demonstrate full integration of vertical optical ring resonators with silicon nanophotonic waveguides on silicon-on-insulator substrates to accomplish a significant step towards 3D photonic integration. The on-chip integration is realized by rolling up 2D differentially strained TiO2 nanomembranes into 3D microtube cavities on a nanophotonic microchip. In this vertical transmission scheme, resonant filtering of optical signals at telecommunication wavelengths is demonstrated and opens up interesting perspectives towards parallel and multi-routing data processing as well as high-throughput optofluidic sensing applications.
Ultra-compact helical antennas for smart system implants
Ultra-compact helical antennas with a total length five times smaller compared to their conventional dipole counterparts are demonstrated to operate in the Industry-Scientific-Medical radio band. The antennas can be implanted by standard medical syringes and inter-antenna as well as antenna-smartphone communication is reported. Our work highlights the potential of helical antennas for medical applications as components of smart system implants.
Magnetism in Möbius rings
In physics of nanomagnetism curvature-induced magnetic effects are subject of exciting current topical studies. In this framework we demonstrate that the magnetic Möbius ring is a unique object because it unites two classes of geometrical effects, namely, topologically induced magnetization patterning and curvature induced chirality symmetry breaking. With this work we complete the broad theoretical studies of various physical phenomena related to the Mobius geometry by including magnetic phenomena. This work was carried out in close collaboration with the Taras Shevchenko National University and the Bogolyubov Institute for Theoretical Physics in Kiev, Ukraine.
Magnetic sense for everybody
We have developed an electronic skin with a magneto-sensory system that equips the recipient with a “sixth sense” able to perceive the presence of static or dynamic magnetic fields. These novel magneto-electronic sensors are less than two micrometers thick and weigh only three gram per square meter. They withstand extreme bending with radii of less than three micrometer, and survive crumpling like a piece of paper without sacrificing the sensor performance. These ultrathin magnetic sensors with extraordinary mechanical robustness are ideally suited to be wearable, yet unobtrusive and imperceptible for orientation and manipulation aids. This work was carried out in close collaboration with the University of Tokyo and Osaka University in Japan.
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Transfer printed stretchable magnetoelectronics
A novel fabrication method for stretchable magnetoresistive sensors is introduced, which relies on the transfer of a complex microsensor system prepared on common rigid donor substrates to prestretched elastomeric membranes in a single step. This direct transfer printing method boosts the fabrication potential of stretchable magnetoelectronics in terms of miniaturization and level of complexity, and provides strain-invariant sensors up to 30% tensile deformation.
Rolled-up functionalized nanomembranes as three-dimensional cavities for single cell studies
We use micropatterning and strain engineering to encapsulate single living mammalian cells into transparent tubular architectures consisting of 3D rolled-up nanomembranes. The spatial confinement of mitotic mammalian cells inside tubular architectures can perturb metaphase plate formation, delay mitotic progression, and cause chromosomal instability in both a transformed and nontransformed human cell line. These findings could provide important clues into how spatial constraints dictate cellular behavior and function. This work was carried out in collaboration with the University of Cambridge in the UK, the Max-Planck-Institute for Intelligent Systems in Germany and the Johns Hopkins University in the US.
Thermal conductivity of mechanically joined nanomembrane superlattices
Hybrid superlattices consisting of a large number of nanomembranes mechanically stacked on top of each other are fabricated by a roll-up and press-back technique. Measurements reveal a two orders reduction of the cross-sectional heat transport through this nanomembrane superlattice compared to a single nanomembrane layer. The low thermal conductivity has the potential to support on-chip solutions for energy harvesters in e.g. micro-autonomous systems.
Large-area rolled-up nanomembrane capacitor arrays
Miniaturization of electronic devices and reduction of their footprint areas are essential ingredients towards efficient development of energy autonomous systems and electronic circuitry. We demonstrate the feasibility of fabricating ultracompact energy storage elements employing rolled-up nanotechnology. These elements highlight the flexibility and high yield of the parallel fabrication process, which results in a substantial reduction in the device dimensions and better integration of the devices into future miniaturized electronic systems.
Impedemetric sensing of ionic fluids and single cells in a single microtube
Ultracompact three-dimensional tubular structures integrating Au-based electrodes serve as impedimetric microsensors for the in-flow determination of mono- and divalent ionic species and HeLa cells. The microsensors show a two orders of magnitude improved performance over conventional planar conductivity detection systems integrated in micro fluidic platforms and the capability to detect single HeLa cells. These highly integrated conductivity tubular sensors open new possibilities towards lab-in-a-tube devices for bioapplications such as biosensing and bioelectronics.
Flexible thermoresponsive microjets
Flexible self-propelled microjets are formed by temperature-induced folding of thin polymer films into microtubes that contain an inner platinum layer for catalytic bubble propulsion in hydrogen peroxide. The polymer films are bilayers of an active and a passive component, which cause the microjets to fold and unfold reversibly by applying slight temperature changes. The speed control by shaping the polymeric Pt films offers a unique approach to operate this new kind of flexible bubble-propelled micromotors. This work was carried out in collaboration with the Leibniz Institute of Polymer Research Dresden, the TU Dresden and the Max-Planck-Institute for Intelligent Systems in Stuttgart.
A sperm driven micro-bio-robot
A new biohybrid micro-robot is developed by capturing bovine sperm cells inside ferromagnetic microtubes that use the motile cells as driving force. These micro-bio-robots can be remotely controlled by an external magnetic field. The performance of micro-robots is described in dependence on tube radius, cell penetration and temperature. The combination of a biological power source and a microdevice is a compelling approach to the development of new microrobotic devices with fascinating future applications such as in-vivo artificial fertilization.
This work was highlighted in:
- www.roboticstomorrow.com (March 2015) URL
- news.discovery.com (January 2014) URL
- Phys.org (January 2014) URL
- Deutschlandfunk (January 2014) URL
- Gizmag (January 2014) URL
- FOX News (December 2013) URL
- Science for the Curious Discover (December 2013) URL
- The Independent (December 2013) URL
- New Scientist (December 2013) URL
- Vice Media Inc. (December 2013) URL
- Le figaro - fr (December 2013) URL
- FierceDrugDelivery (December 2013) URL
- Tech Times (December 2013) URL
Domain patterns of magnetic rolled-up microtubes
Rolled-up magnetic microtubes display spiral-like, longitudinally or azimuthally magnetized domain patterns. The rolled-up geometry offers an elegant possibility for tailoring the fundamental magnetic interactions at the nanoscale in three-dimensions. The novel magnetic-domain patterns have a strong impact on their magnetic response and transport properties and could be attractive for future magnetoimpedance-based field sensors.
A wavelength-tunable single-photon emitting diode
The first all-electrically operated wavelength-tunable single-photon source is demonstrated. The device consists of an ultra-thin light-emitting diode containing self-assembled quantum dots integrated onto a piezoelectric crystal.Triggered single photons are generated via injection of short electrical pulses at operation speeds up to 0.8 GHz. The wavelength of the emitted single-photons can be tuned over a broad range by the strain field from the piezoelectric crystal.Our work provides exciting perspectives towards high data rate quantum communications relying on remote electrically-driven single-photon sources.
Stretching quantum dots till they become light
We demonstrate the creation of a light-hole exciton ground state by applying elastic stress to an initially unstrained quantum dot. The signature is clearly distinct from that of the well-known heavy-hole exciton and consists of three orthogonally polarized bright optical transitions and a fine-structure splitting of hundreds of microelectron volts between in-plane and out-of-plane components. Our work paves the way for the exploration of the fundamental properties of three-dimensionally confined light-hole states in quantum technologies and was carried out in collaboration with the Johannes Kepler Universität in Linz, the Kavli Institute at the TU Delft and the Max-Planck Institute for Solid State Research in Stuttgart.
Y.H. Huo et al., Nat. Phys. 10, 46 (2014) URL PDF
This work was highlighted in:
Multichannel anodes for lithium-ion batteries
We employed rolled-up nanotechnology to fabricate sandwich-stacked SnO2/Cu hybrid nanosheets as multichannel anodes for lithium-ion batteries with the use of carbon black as inter-sheet spacer. The sandwich-stacked SnO2/Cu hybrid nanosheets exhibit significant improvement in cyclability compared to SnO2 nanosheets and SnO2/Cu hybrid nanosheets. By employing a direct self-rolling and compressing approach, a much higher effective volume efficiency is achieved as compared to rolled-up hollow tubes. This synthesis approach presents a promising route to design multichannel anodes for high performance Li-ion batteries.
Vertical add-drop filter made from a rolled-up ring resonator
A significant step towards integrated vertically rolled-up microcavities is demonstrated by interfacing SiO2 microtube optical ring resonators with tapered fibers. In this transmission configuration, resonant filtering of optical signals at telecommunication wavelengths is shown in subwavelength thick walled microcavities. Moreover, we present a four-port add-drop filter based on a lifted doubly interfaced vertically rolled-up microcavity. Our work opens opportunities for vertical resonant light transfer in 3D multi-level optical data processing as well as for massively parallel optofluidic analysis of biomaterials in lab-on-a-chip systems.
S. Böttner et al., Appl. Phys. Lett. 102, 251119 (2013) URL PDF
Chemotactic behaviour of artificial engines
When man-made self-powered micromotors swim in a gradient of chemical fuel, they experience a chemical attraction towards the fuel and deviate from their otherwise random motion. We now report that self-propelled microjets and microparticles change their trajectory when hydrogen peroxide fuel is added to the solution in which they navigate, a response similar to the chemotactic behavior of some living organisms.
Diamond lattice photonic crystals from rolled-up membranes
A novel method for the fabrication of diamond lattice photonic crystals by rolling strained pre-patterned titania membranes is proposed. Using rolled-up nanotechnology, full band gap and highly customizable partial band gap photonic crystals are possible. A combination of finite element analysis and band structure calculations of our proposed system shows that photonic crystal bending negligibly influences the band gap, and that at least six windings are necessary. These findings motivate further efforts towards the fabrication of rolled-up photonic crystals.
M. R. Jorgensen et al., Phys. Rev. A. 87, 041803 (2013) URL PDF
Dynamic molecular processes detected by nanomembrane based microtube cavities
Dynamic molecular processes of water and ethanol are detected on the surface of rolled-up opto-chemical microtube resonators. Based on perturbation theory, quantitative information about structural changes in molecular layers are acquired. A robust ice-like H2O molecular layer on the microtube surface was revealed through detecting molecular interactions at room temperature. The ability of the self-assembled microtube cavities to probe molecular changes on the sensing surface constitutes a versatile platform for the detection of diverse surface phenomena in a label-free fashion.
L. B. Ma et al., Adv. Mater. 25, 2357 (2013). URL PDF
New battery research: rolled-up trilayer nanomembranes improve durability and lifetime
We report a new type of tubular configuration made from naturally rolled-up C/Si/C trilayer nanomembranes. A high capacity of ~2000 mAh g-1 can be retained at a current density of 50 mA g-1 without discernible decay, and the capacity can keep ~1000 mAh g-1 even after 300 cycles at 500 mA g-1 with almost 100% capacity retention. The trilayer structure design provides a stable conductive network and prevents Si pulverization and aggregation during cycling, thus guaranteeing superior electrochemical performance.
Rolled-up field effect transistors
We fabricate inorganic thin film transistors with bending radii of less than 5μm maintaining their high electronic performance with on-off ratios of more than 100.000 and subthreshold swings of 160mV/dec. The fabrication technology relies on the roll-up of highly strained semiconducting nanomembranes, which compacts planar transistors into three-dimensional tubular architectures. The rolled-up transistors are perfectly embedded into the wall of a cylindrical fluidic channel, which may boost the performance of large-scale integrated microfluidics to a level way beyond of what is currently available.
Rolling their own for energy storage devices
We report a novel hybrid tubular structure composed of multilayer Ge and Ti nanomembranes with superior reversible capacity by rolled-up nanotech. The intrinsic strain accommodated in the Ge/Ti bilayer nanomembranes is efficiently released by a self-rolling process that thus offers a minimization of the whole system energy. The high conductivity, fast lithium ion diffusion and good volume tolerance of the material are evaluated by single tube devices. The proof of concept in this work paves the way for integration of microbatteries for chip-scale applications.
This work was highlighted in:
Renewable Energy (May, 2013) URL