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Artificial magnetoception, i.e., electronically expanding human perception to detect magnetic fields, is a new and yet unexplored way for interacting with our surroundings. This technology relies on thin, soft, and flexible magnetic field sensors, dubbed magnetosensitive electronic skins (e-skins), which so far have focused on detecting in-plane magnetic fields. Here, we demonstrate a compliant platform sensitive to out-of-plane magnetic fields and with tunable logic characteristics. This combination of functions is assured by the here designed and realized world’s first mechanically flexible spin valve element featuring sensitivity to out-of-plane magnetic fields. We envision that this technology platform will pave the way towards magnetoreceptive human-machine interfaces or virtual- and augmented reality applications, which are intuitive to use, energy efficient, and insensitive to external magnetic disturbances.

This work is a result of a fruitful cooperation between the Helmholtz-Zentrum Dresden-Rossendorf e.V., Università Politecnica delle Marche (group of Prof. Gianni Barucca), Politecnico di Milano (group of Prof. Christian Rinaldi), University of Augsburg (group of Prof. Manfred Albrecht), and CNR Istituto di Struttura della Materia (group of Dr. Gaspare Varvaro).

P. Makushko, E. S. Oliveros Mata, G. S. Cañón Bermúdez, M. Hassan, S. Laureti, C. Rinaldi, F. Fagiani, G. Barucca, N. Schmidt, Y. Zabila, T. Kosub, R. Illing, O. Volkov, I. Vladymyrskyi, J. Fassbender, M. Albrecht, G. Varvaro, and D. Makarov
Flexible magnetoreceptor with tunable intrinsic logic for on-skin touchless human-machine interfaces
Adv. Funct. Mater. 31, 2101089 (2021). URL PDF 

Origami approaches are broadly used in material science and technology for the realization of smart actuators mimicking the behavior of living organisms and their ability to respond to an external stimuli. We report on magnetic origami actuators equipped with highly flexible magnetic field sensors allowing to monitor the shape of the actuator and detect its magnetization state. The on-board magnetic field sensors enable feedback contrl and guided assembly. These actuators are based on composite films of ferromagnetic microparticles embedded in shape-memory polymer films. Photothermal heating from light and applied magnetic fields enable on-demand reconfigurability. This work constitutes a synergy between two research fields of soft actuators and soft electronics. Smart magnetic origami will pave the way to inspire the remote and hands-free operation of robotic systems where the human intervention and direct optical observation is limited. By extending the here explored magnetically driven actuation to other stimuli, the technology demonstrated in this work can result in a new class of smart soft robots, which are able to adjust their state by communicating with the external devices.

This work is a result of a fruitful cooperation between the Helmholtz-Zentrum Dresden-Rossendorf e.V., Elon University (Prof. Benjamin A. Evans) and North Carolina State University (group of Prof. Joseph B. Tracy).

M. Ha, G. S. Cãnón Bermúdez, J. A.-C. Liu, E. S. Oliveros Mata, B. A. Evans, J. B. Tracy, and D. Makarov
Reconfigurable magnetic origami actuators with on-board sensing for guided assembly
Adv. Mater. 33, 2008751 (2021). URL PDF 

Actuation-assisted bioanalysis represents an emerging application of micromachines, including microactuators, motors, and microrobotic devices. Here, micromachines consisting of tailorable microcompartments are synthesized by microfluidics-directed assembly. Apart from the contrl over the geometric parameters of the compartments, a novel emulsion fission approach is devised to precisely allocate the magnetic content in between the compartments of the dimer structures. This unlocks a couple of new degrees of freedom to engineer magnetic coupling in discrete magnetic structure assemblies and uncovers a series of multifunctional microactuators for complex and dynamic bioanalysis.

This work is a result of a fruitful cooperation between the Helmholtz-Zentrum Dresden-Rossendorf e.V., The University of Technology Sydney (group of Dr. Gungun Lin and Prof. Dayong Jin) and State Key Laboratory of Rare Earth Resource Utilization of the Chinese Academy of Sciences (group of Prof. Jun Lin).

G. Lin, Y. Liu, G. Huang, Y. Chen, D. Makarov, J. Lin, Z. Quan, and D. Jin
3D Rotation-Trackable and Differentiable Micromachines with Dimer-Type Structures for Dynamic Bioanalysis
Advanced Intelligent Systems 3, 2000205 (2021). URL PDF

We report that stray magnetic fields can code and decode a collection of hierarchically-assembled beads. By the microfluidic assembling of mesoscopic superparamagnetic cores, diverse and non-volatile stray magnetic field response can be built in the series of microscopic spheres, dumbbells, pears, chains and triangles. Remarkably, the set of stray magnetic field fingerprints are readily discerned by a compact giant magnetoresistance sensor for parallelised screening of multiple distinctive pathogenic DNAs. This opens up the magneto-multiplexing opportunity and could enable streamlined assays to incorporate magneto-mixing, washing, enrichment and separation of analytes. This strategy therefore suggests a potential point-of-care testing solution for efficient kinetic assays.

This work is a result of a fruitful cooperation between the Helmholtz-Zentrum Dresden-Rossendorf e.V., The University of Technology Sydney (group of Dr. Gungun Lin and Prof. Dayong Jin) and Minomic International Ltd. (group of Bradley J. Walsh).

Y. Liu, G. Lin, Y. Chen, I. Mönch, D. Makarov, B. J. Walsh, and D. Jin
Coding and decoding stray magnetic fields for multiplexing kinetic bioassay platform
Lab Chip 20, 4561 (2020). URL   

We introduced a novel strategy to fabricate Janus micromotors through a microfluidic method by adhering functional nanoparticles (NPs) onto microspheres functionalized with a photocurable hydrogel precursor. The proposed approach allows us to fabricate Janus particles with tunable coverage of a hydrogel sphere with functional NPs (including photocatalytic TiO2, magnetic Fe3O4 and catalytic MnO2), hence enabling a straightforward tailoring of physical and chemical responses of the capped spheres under external stimuli (UV light illumination, concentration of H2O2 and magnetic field). The method can be readily extended to prepare multifunctional Janus micromotors by using various kinds of functional NPs (e.g., catalytic MnO2 and magnetic Fe3O4) during the fabrication. In addition to the detailed study of the fundamentals of the complex motion dynamics of Janus spheres, we revealed the potential of our TiO2 Janus microspheres for performing useful tasks in environmental applications with the focus on water purification.

This work is a result of a fruitful cooperation between the HZDR and the group of Prof. Yongfeng Mei at the Fudan University in Shanghai, China.

X. Lin, H. Zhu, Z. Zhao, C. You, Y. Kong, Y. Zhao, J. Liu, H. Chen, X. Shi, D. Makarov, and Y. F. Mei
Hydrogel-based Janus Micromotors Capped with Functional Nanoparticles for Environmental Applications
Adv. Mater. Technol. 5, 2000279 (2020). URL PDF   

Here we realize periodic magnetic domain structures in sub-200 nm wide linear as well as curved magnets, embedded within a flat non-ferromagnetic thin film. The nanomagnets are produced within a non-ferromagnetic B2-ordered Fe60Al40 thin film, where local irradiation by a focused ion beam causes the formation of disordered and strongly ferromagnetic regions of A2 Fe60Al40. We study anisotropic lattice relaxation, which generates a magnetic easy-axis parallel to the short axis. The competing effect of the strain and shape anisotropies stabilizes a periodic domain pattern in linear as well as spiral nanomagnets, providing a versatile and geometrically controllable path to engineering the strain and thereby the magnetic anisotropy at the nanoscale.

This work is a result of a fruitful cooperation of the HZDR team with the University of Glasgow and University of Antwerp.

M. Nord, A. Semisalova, A. Kákay, G. Hlawacek, I. MacLaren, V. Liersch, O. M. Volkov, D. Makarov, G. W. Paterson, K. Potzger, J. Lindner, J. Fassbender, D. McGrouther, and R. Bali
Strain Anisotropy and Magnetic Domains in Embedded Nanomagnets
Small 15, 1904738 (2019). URL PDF   

Numerous flexible diagnostic or therapeutic devices have been already successfully demonstrated. However, cancer treatment remains rather unexplored in the field of flexible electronics. Here, we propose an approach to targeted cancer treatment which relies on the implantation at the tumor site of an ultra-thin flexible device comprising a resistive heater and temperature sensor. The device is fabricated on a 6 micrometer thick polymeric foil, which seamlessly conforms to the very soft liver tissue and allows for precisely controlled thermal treatment. We demonstrate a proof-of-concept prototype and evaluate its electrical and mechanical performance when applied to murine models. The presented multifunctional and highly compliant device paves the way for targeting of exophytic tumor nodules via thermal destruction of tissue, targeted drug release, or enhancement of anti-tumor immune responses. In addition, it raises the possibility to further study the effects of thermal treatment in enhancing the development of the new cancer therapies, especially for severe malignancies as liver cancer.

This work is the result of a fruitful cooperation between the Helmholtz-Zentrum Dresden-Rossendorf e.V. and Hannover Medical School (groups of Dr. T. Yevsa and Dr. Dr. A. Potthoff).

G. S. Cãnón Bermúdez, A. Kruv, T. Voitsekhivska, I. Hochnadel, A. Lebanov, A. Potthoff, J. Fassbender, T. Yevsa, and D. Makarov
Implantable Highly Compliant Devices for Heating of Internal Organs: Toward Cancer Treatment
Adv. Eng. Mater. 21, 1900407 (2019). URL    

We here demonstrate the experimental and theoretical study of the curvature effects in planar magnetic parabolic stripes. We show that a proper design of magnetic patterns reveal curvature-driven changes of static magnetic properties in parabolic nanostripes. The shape of a parabolic stripe is tuned to cover broad range of widths and curvatures allowing to construct a phase diagram of magnetic equilibrium states. For this, joint experimental, i.e. soft X-ray imaging, and theoretical studies are carried out. Analytical calculations in the framework, when non-local magnetostatic effects are neglected, coincide with the experimental and simulation results in a broad range of parameters. Our results give confidence in the applicability of the existing theoretical framework for further analytical considerations of equilibrium magnetization states of curvilinear nanomagnets.

This work is the result of a fruitful cooperation between the Helmholtz-Zentrum Dresden-Rossendorf e.V. and Helmholtz-Zentrum Berlin für Materialien und Energie (group of Dr. Florian Kronast).

O. M. Volkov, F. Kronast, I. Mönch, M.-A. Mawass, A. Kakay, J. Fassbender, and D. Makarov
Experimental and theoretical study of curvature effects in parabolic nanostripes
Physica Status Solidi (RRL) - Rapid Research Letters 13, 1800309 (2019). URL PDF   

We here demonstrated for the first time electronic skins capable of perceiving direction in space based on the interaction with geomagnetic field exclusively. In this respect, we realized a highly compliant e-skin compass relying on geometrically conditioned anisotropic magnetoresistive (AMR) sensors fabricated on ultra-thin polymeric foils. Our highly compliant magnetosensory system enables real time tracking of the position of a body in space as well as the touchless manipulation of virtual objects based on the biomagnetic orientation as needed for virtual and augmented reality applications.

G. S. Cañón Bermúdez, H. Fuchs, L. Bischoff, J. Fassbender, and D. Makarov
Electronic-skin compasses for geomagnetic field driven artificial magnetoception and interactive electronics
Nature Electronics 1, 589 (2018). URL    

Self-propelled Janus particles, acting as microscopic vehicles, have the potential of performing complex tasks on a microscopic scale, suitable, e.g., for environmental applications, on chip chemical computer, or in vivo drug delivery. Development of these smart nano-devices requires a better understanding of how synthetic swimmers move in crowded and confined geometry that mimic actual microenvironment. We demonstrate experimentally and in simulations the intriguing transport phenomena, observed while placing both, catalytic Janus swimmers and passive particles into narrow channels confinement. This work represents an important milestone towards understanding and further fabrication of realistic bioinspired complex networks, containing synthetic autonomous micro- and nano-machines to perform the tasks in a mixture with passive objects.

This work is the result of a fruitful cooperation between the Dresden University of Technology (group of Dr. Larysa Baraban), University of Antwerpen (group of Dr. Misko), Tongji University (Prof. Marchesoni), University of Michigan (Prof. Nori), and Helmholtz-Zentrum Dresden-Rossendorf e.V.

H. Yu, A. Kopach, V. R. Misko, A. A. Vasylenko, D. Makarov, F. Marchesoni, F. Nori, L. Baraban, and G. Cuniberti
Confined catalytic Janus swimmers in a crowded channel: Geometry-driven rectification transients and directional locking
Small 12, 5882 (2016). URL      

We demonstrated a logic-controlled magnetic flow cytometric system for controlled synthesis of magnetic encoded microcarriers in multiphase flow networks. The system provides a first solution for the quality administration and screening of magnetic suspension arrays and addresses the universal need of process contrl in microfluidic networks.

G. Lin, D. D. Karnaushenko, G. S. Cañón Bermúdez, O. G. Schmidt, and D. Makarov
Magnetic suspension array technology: Controlled synthesis and screening in microfluidic networks
Small 12, 4553 (2016). URL PDF     

We realized the first entirely flexible integrated magnetic field sensor system consisting of a flexible giant magnetoresistive bridge on-site conditioned using high-performance IGZO-based readout electronics. With the remarkable sensitivity of 25 V/V/kOe, the system outperforms commercial fully integrated rigid magnetic sensors by at least one order of magnitude, whereas all components stay fully functional when bend to a radius of 5 mm.

N. Münzenrieder, D. Karnaushenko, L. Petti, G. Cantarella, C. Vogt, L. Büthe, D.D. Karnaushenko, O. G. Schmidt, D. Makarov, and G. Tröster
Entirely flexible on-site conditioned magnetic sensorics
Adv. Electron. Mater. 2, 1600188 (2016). URL PDF     

We introduced smart biomimetics - a unique class of devices combining mechanical adaptivity of soft actuators with the imperceptibility of microelectronics. Due to the inherent ability to self-assemble, biomimetic microelectronics can firmly yet gently attach to an inorganic or biological tissue enabling enclosure of, e.g. nervous fibers, or guiding the growth of neuronal cells during regeneration.

D. Karnaushenko, N. Münzenrieder, D. D. Karnaushenko, B. Koch, A. K. Meyer, S. Baunack, L. Petti, G. Tröster, D. Makarov, and O. G. Schmidt
Biomimetic microelectronics for regenerative neuronal cuff implants
Adv. Mater. 27, 6797 (2015). URL PDF     

A flexible light weight diagnostic platform is realized on cost-efficient large-area flexible foils enabling its cost-efficient high-volume delivery to medical institutions worldwide. The devices allow the timely diagnosis of viral or infectious diseases, for example, the here demonstrated H1N1 subtype of the Avian Influenza Virus. 

D. Karnaushenko, B. Ibarlucea, S. Lee, G. Lin, L. Baraban, S. Pregl, M. Melzer, D. Makarov, T. Mikolajick, O. G. Schmidt, and G. Cuniberti
Light weight and flexible high-performance diagnostic platform
Adv. Healthcare Mater. 4, 1517 (2015). URL PDF

High-performance giant magnetoresistive (GMR) sensorics are realized, which are printed at predefined locations on flexible circuitry. Remarkably, the printed magnetosensors remain fully operational over the complete consumer temperature range and reveal a giant magnetoresistance up to 37 % and a sensitivity of 0.93 T?1 at 130 mT. With these specifications, printed magnetoelectronics can be controlled using flexible active electronics for the realization of smart packaging and energy-efficient switches.

D. Karnaushenko, D. Makarov, M. Stöber, D. D. Karnaushenko, S. Baunack, and O. G. Schmidt
High-performance magnetic sensorics for printable and flexible electronics
Adv. Mater. 27, 880 (2015). URL PDF

We fabricated permalloy (Fe19Ni81) nanomembranes rolled-up into compact three-dimensional architectures. Our experimental study highlights the dominant influence of the magnetostatic interaction between multiple windings of rolled-up nanomembranes inducing the anti-parallel alignment of the magnetic moments between adjacent layers of the rolled-up tube. This leads to geometrically induced complex spiral-like magnetic domains.

R. Streubel, D. Makarov, J. Lee, C. Müller, M. Melzer, R. Schäfer, C. C. B. Bufon, S.-K. Kim, and O. G. Schmidt
Rolled-up permalloy nanomembranes with multiple windings
SPIN 3, 1340001 (2013). URL PDF

A large variety of electronic components assembled as printable optoelectronic devices and communication modules are already commercially available. However, the element responding to a magnetic field has been realized only very recently. Here, we position the novel topic of printable magnetic sensorics in a family of printable electronics and highlight possible application directions of this technology.

D. Makarov, D. Karnaushenko, and O. G. Schmidt
Printable magnetoelectronics
ChemPhysChem 14, 1771 (2013). URL PDF