Publications
56 results found
Ainla A, Hamedi MM, Guder F, et al., 2017, Electrical textile valves for paper microfluidics, Advanced Materials, Vol: 29, Pages: 1-10, ISSN: 0935-9648
This paper describes electrically-activated fluidic valves that operate based on electrowetting through textiles. The valves are fabricated from electrically conductive, insulated, hydrophobic textiles, but the concept can be extended to other porous materials. When the valve is closed, the liquid cannot pass through the hydrophobic textile. Upon application of a potential (in the range of 100–1000 V) between the textile and the liquid, the valve opens and the liquid penetrates the textile. These valves actuate in less than 1 s, require low energy (≈27 µJ per actuation), and work with a variety of aqueous solutions, including those with low surface tension and those containing bioanalytes. They are bistable in function, and are, in a sense, the electrofluidic analog of thyristors. They can be integrated into paper microfluidic devices to make circuits that are capable of controlling liquid, including autonomous fluidic timers and fluidic logic.
Hamedi MM, Ainla A, Guder F, et al., 2016, Integrating Electronics and Microfluidics on Paper, ADVANCED MATERIALS, Vol: 28, Pages: 5054-5063, ISSN: 0935-9648
Guder F, Ainla A, Redston J, et al., 2016, Paper-based electrical respiration sensor, Angewandte Chemie International Edition, Vol: 55, Pages: 5727-5732, ISSN: 1433-7851
Current methods of monitoring breathing require cumbersome, inconvenient, and often expensive devices; this requirement sets practical limitations on the frequency and duration of measurements. This article describes a paper-based moisture sensor that uses the hygroscopic character of paper (i.e. the ability of paper to adsorb water reversibly from the surrounding environment) to measure patterns and rate of respiration by converting the changes in humidity caused by cycles of inhalation and exhalation to electrical signals. The changing level of humidity that occurs in a cycle causes a corresponding change in the ionic conductivity of the sensor, which can be measured electrically. By combining the paper sensor with conventional electronics, data concerning respiration can be transmitted to a nearby smartphone or tablet computer for post-processing, and subsequently to a cloud server. This means of sensing provides a new, practical method of recording and analyzing patterns of breathing.
Hamedi MM, Campbell VE, Rothemund P, et al., 2016, Electrically Activated Paper Actuators, ADVANCED FUNCTIONAL MATERIALS, Vol: 26, Pages: 2446-2453, ISSN: 1616-301X
Boehler C, Guder F, Kuecuekbayrak UM, et al., 2016, A simple approach for molecular controlled release based on atomic layer deposition hybridized organic-inorganic layers, Scientific Reports, Vol: 6, Pages: 1-12, ISSN: 2045-2322
On-demand release of bioactive substances with high spatial and temporal control offers ground-breaking possibilities in the field of life sciences. However, available strategies for developing such release systems lack the possibility of combining efficient control over release with adequate storage capability in a reasonably compact system. In this study we present a new approach to target this deficiency by the introduction of a hybrid material. This organic-inorganic material was fabricated by atomic layer deposition of ZnO into thin films of polyethylene glycol, forming the carrier matrix for the substance to be released. Sub-surface growth mechanisms during this process converted the liquid polymer into a solid, yet water-soluble, phase. This layer permits extended storage for various substances within a single film of only a few micrometers in thickness and hence demands minimal space and complexity. Improved control over release of the model substance Fluorescein was achieved by coating the hybrid material with a conducting polymer film. Single dosage and repetitive dispensing from this system was demonstrated. Release was controlled by applying a bias potential of ±0.5 V to the polymer film enabling or respectively suppressing the expulsion of the model drug. In vitro tests showed excellent biocompatibility of the presented system.
Glavan AC, Niu J, Chen Z, et al., 2016, Analytical Devices Based on Direct Synthesis of DNA on Paper, Analytical Chemistry, Vol: 88, Pages: 725-731, ISSN: 0003-2700
This paper addresses a growing need in clinical diagnostics for parallel, multiplex analysis of biomarkers from small biological samples. It describes a new procedure for assembling arrays of ssDNA and proteins on paper. This method starts with the synthesis of DNA oligonucleotides covalently linked to paper and proceeds to assemble microzones of DNA-conjugated paper into arrays capable of simultaneously capturing DNA, DNA-conjugated protein antigens, and DNA-conjugated antibodies. The synthesis of ssDNA oligonucleotides on paper is convenient and effective with 32% of the oligonucleotides cleaved and eluted from the paper substrate being full-length by HPLC for a 32-mer. These ssDNA arrays can be used to detect fluorophore-linked DNA oligonucleotides in solution, and as the basis for DNA-directed assembly of arrays of DNA-conjugated capture antibodies on paper, detect protein antigens by sandwich ELISAs. Paper-anchored ssDNA arrays with different sequences can be used to assemble paper-based devices capable of detecting DNA and antibodies in the same device and enable simple microfluidic paper-based devices.
Vierrath S, Gueder F, Menzel A, et al., 2015, Enhancing the quality of the tomography of nanoporous materials for better understanding of polymer electrolyte fuel cell materials, JOURNAL OF POWER SOURCES, Vol: 285, Pages: 413-417, ISSN: 0378-7753
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- Citations: 39
Menzel A, Komin K, Yang Y, et al., 2015, Ultra-long zinc oxide nanowires and boron doping based on ionic liquid assisted thermal chemical vapor deposition growth, NANOSCALE, Vol: 7, Pages: 92-97, ISSN: 2040-3364
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- Citations: 11
So J-H, Tayi AS, Gueder F, et al., 2014, Stepped Moduli in Layered Composites, ADVANCED FUNCTIONAL MATERIALS, Vol: 24, Pages: 7197-7204, ISSN: 1616-301X
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- Citations: 13
Gueder F, Frei E, Kuecuekbayrak UM, et al., 2014, Engineered High Aspect Ratio Vertical Nanotubes as a Model System for the Investigation of Catalytic Methanol Synthesis Over Cu/ZnO, ACS APPLIED MATERIALS & INTERFACES, Vol: 6, Pages: 1576-1582, ISSN: 1944-8244
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- Citations: 9
Wongchoosuk C, Subannajui K, Wang C, et al., 2014, Electronic nose for toxic gas detection based on photostimulated core-shell nanowires, RSC ADVANCES, Vol: 4, Pages: 35084-35088, ISSN: 2046-2069
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- Citations: 25
Kozhummal R, Yang Y, Gueder F, et al., 2013, Antisolvent Crystallization Approach to Construction of CuI Superstructures with Defined Geometries, ACS NANO, Vol: 7, Pages: 2820-2828, ISSN: 1936-0851
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- Citations: 25
Gueder F, Yang Y, Kuecuekbayrak UM, et al., 2013, Tracing the Migration History of Metal Catalysts in Metal-Assisted Chemically Etched Silicon, ACS NANO, Vol: 7, Pages: 1583-1590, ISSN: 1936-0851
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- Citations: 22
Subannajui K, Menzel A, Gueder F, et al., 2013, Large-Scale Nano Piezo Force Position Arrays as Ultrahigh-Resolution Micro- and Nanoparticle Tracker, ADVANCED FUNCTIONAL MATERIALS, Vol: 23, Pages: 191-197, ISSN: 1616-301X
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- Citations: 12
Menzel A, Guebeli RJ, Gueder F, et al., 2013, Detection of real-time dynamics of drug-target interactions by ultralong nanowalls, LAB ON A CHIP, Vol: 13, Pages: 4173-4179, ISSN: 1473-0197
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- Citations: 11
Gueder F, Yang Y, Menzel A, et al., 2012, Superior Functionality by Design: Selective Ozone Sensing Realized by Rationally Constructed High-Index ZnO Surfaces, SMALL, Vol: 8, Pages: 3307-3314, ISSN: 1613-6810
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- Citations: 20
Kozhummal R, Yang Y, Gueder F, et al., 2012, Homoepitaxial Branching: An Unusual Polymorph of Zinc Oxide Derived from Seeded Solution Growth, ACS NANO, Vol: 6, Pages: 7133-7141, ISSN: 1936-0851
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- Citations: 48
Subannajui K, Gueder F, Danhof J, et al., 2012, An advanced fabrication method of highly ordered ZnO nanowire arrays on silicon substrates by atomic layer deposition, NANOTECHNOLOGY, Vol: 23, ISSN: 0957-4484
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- Citations: 18
Menzel A, Subannajui K, Gueder F, et al., 2011, Multifunctional ZnO-Nanowire-Based Sensor, ADVANCED FUNCTIONAL MATERIALS, Vol: 21, Pages: 4342-4348, ISSN: 1616-301X
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- Citations: 106
Gueder F, Yang Y, Goetze S, et al., 2011, Toward Discrete Multilayered Composite Structures: Do Hollow Networks Form in a Polycrystalline Infinite Nanoplane by the Kirkendall Effect?, CHEMISTRY OF MATERIALS, Vol: 23, Pages: 4445-4451, ISSN: 0897-4756
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- Citations: 12
Subannajui K, Gueder F, Zacharias M, 2011, Bringing Order to the World of Nanowire Devices by Phase Shift Lithography, NANO LETTERS, Vol: 11, Pages: 3513-3518, ISSN: 1530-6984
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- Citations: 16
Gueder F, Yang Y, Danhof J, et al., 2011, Improved optical properties of ZnO thin films by concurrently introduced interfacial voids during thermal annealing, APPLIED PHYSICS LETTERS, Vol: 99, ISSN: 0003-6951
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- Citations: 18
Yang Y, Liu L, Gueder F, et al., 2011, Regulated Oxidation of Nickel in Multisegmented Nickel-Platinum Nanowires: An Entry to Wavy Nanopeapods, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, Vol: 50, Pages: 10855-10858, ISSN: 1433-7851
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- Citations: 19
Gueder F, Yang Y, Krueger M, et al., 2010, Atomic Layer Deposition on Phase-Shift Lithography Generated Photoresist Patterns for 1D Nanochannel Fabrication, ACS APPLIED MATERIALS & INTERFACES, Vol: 2, Pages: 3473-3478, ISSN: 1944-8244
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- Citations: 19
Yang Y, Guder F, Zacharias M, 2010, Diffusion-Induced Void Evolution in Core-Shell Nanowires: Elaborated View on the Nanoscale Kirkendall Effect, ISRAEL JOURNAL OF CHEMISTRY, Vol: 50, Pages: 439-448, ISSN: 0021-2148
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- Citations: 14
Gueder F, Yang Y, Goetze S, et al., 2010, Controlled Positioning of Large Interfacial Nanocavities via Stress-Engineered Void Localization, SMALL, Vol: 6, Pages: 1603-1607, ISSN: 1613-6810
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- Citations: 25
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