1
|
Pereira A, Sáez G, Saavedra E, Escrig J. Tunable Magnetic Properties of Interconnected Permalloy Nanowire Networks. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:1971. [PMID: 37446487 DOI: 10.3390/nano13131971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 06/22/2023] [Accepted: 06/25/2023] [Indexed: 07/15/2023]
Abstract
In this study, we investigate the magnetic properties of interconnected permalloy nanowire networks using micromagnetic simulations. The effects of interconnectivity on the hysteresis curves, coercivity, and remanence of the nanowire networks are analyzed. Our results reveal intriguing characteristics of the hysteresis curves, including nonmonotonic behaviors of coercivity as a function of the position of horizontal nanowires relative to vertical nanowires. By introducing horizontal nanowires at specific positions, the coercivity of the nanowire networks can be enhanced without altering the material composition. The normalized remanence remains relatively constant regardless of the position of the horizontal wires, although it is lower in the interconnected nanowire arrays compared to nonconnected arrays. These findings provide valuable insights into the design and optimization of nanowire networks for applications requiring tailored magnetic properties.
Collapse
Affiliation(s)
- Alejandro Pereira
- Department of Sciences, Faculty of Liberal Arts, Adolfo Ibañez University, Santiago 7941169, Chile
| | - Guidobeth Sáez
- Department of Physics, Faculty of Physical and Mathematical Sciences, University of Chile, Santiago 8370448, Chile
| | - Eduardo Saavedra
- Department of Physics, University of Santiago de Chile (USACH), Santiago 9170124, Chile
| | - Juan Escrig
- Department of Physics, University of Santiago de Chile (USACH), Santiago 9170124, Chile
- Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Santiago 9170124, Chile
| |
Collapse
|
2
|
Marchal N, da Câmara Santa Clara Gomes T, Abreu Araujo F, Piraux L. Interplay between diffusion and magnon-drag thermopower in pure iron and dilute iron alloy nanowire networks. Sci Rep 2023; 13:9280. [PMID: 37286659 DOI: 10.1038/s41598-023-36391-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 06/02/2023] [Indexed: 06/09/2023] Open
Abstract
Results of measurements on the thermoelectric power of 45 nm diameter interconnected nanowire networks consisting of pure Fe, dilute FeCu and FeCr alloys and Fe/Cu multilayers are presented. The thermopower values of Fe nanowires are very close to those found in bulk materials, at all temperatures studied between 70 and 320 K. For pure Fe, the diffusion thermopower at room temperature, estimated to be around - 15 [Formula: see text]V/K from our data, is largely supplanted by the estimated positive magnon-drag contribution, close to 30 [Formula: see text]V/K. In dilute FeCu and FeCr alloys, the magnon-drag thermopower is found to decrease with increasing impurity concentration to about 10 [Formula: see text]V/K at 10[Formula: see text] impurity content. While the diffusion thermopower is almost unchanged in FeCu nanowire networks compared to pure Fe, it is strongly reduced in FeCr nanowires due to pronounced changes in the density of states of the majority spin electrons. Measurements performed on Fe(7 nm)/Cu(10 nm) multilayer nanowires indicate a dominant contribution of charge carrier diffusion to the thermopower, as previously found in other magnetic multilayers, and a cancellation of the magnon-drag effect. The magneto-resistance and magneto-Seebeck effects measured on Fe/Cu multilayer nanowires allow the estimation of the spin-dependent Seebeck coefficient in Fe, which is about - 7.6 [Formula: see text]V/K at ambient temperature.
Collapse
Affiliation(s)
- Nicolas Marchal
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Place Croix du Sud 1, 1348, Louvain-la-Neuve, Belgium
| | | | - Flavio Abreu Araujo
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Place Croix du Sud 1, 1348, Louvain-la-Neuve, Belgium
| | - Luc Piraux
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Place Croix du Sud 1, 1348, Louvain-la-Neuve, Belgium.
| |
Collapse
|
3
|
da Câmara Santa Clara Gomes T, Marchal N, Abreu Araujo F, Piraux L. Flexible Active Peltier Coolers Based on Interconnected Magnetic Nanowire Networks. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:nano13111735. [PMID: 37299636 DOI: 10.3390/nano13111735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/19/2023] [Accepted: 05/22/2023] [Indexed: 06/12/2023]
Abstract
Thermoelectric energy conversion based on flexible materials has great potential for applications in the fields of low-power heat harvesting and solid-state cooling. Here, we show that three-dimensional networks of interconnected ferromagnetic metal nanowires embedded in a polymer film are effective flexible materials as active Peltier coolers. Thermocouples based on Co-Fe nanowires exhibit much higher power factors and thermal conductivities near room temperature than other existing flexible thermoelectric systems, with a power factor for Co-Fe nanowire-based thermocouples of about 4.7 mW/K2m at room temperature. The effective thermal conductance of our device can be strongly and rapidly increased by active Peltier-induced heat flow, especially for small temperature differences. Our investigation represents a significant advance in the fabrication of lightweight flexible thermoelectric devices, and it offers great potential for the dynamic thermal management of hot spots on complex surfaces.
Collapse
Affiliation(s)
| | - Nicolas Marchal
- Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain, Place Croix du Sud 1, 1348 Louvain-la-Neuve, Belgium
| | - Flavio Abreu Araujo
- Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain, Place Croix du Sud 1, 1348 Louvain-la-Neuve, Belgium
| | - Luc Piraux
- Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain, Place Croix du Sud 1, 1348 Louvain-la-Neuve, Belgium
| |
Collapse
|
4
|
Belim SV, Bychkov IV. Magnetic Properties of 2D Nanowire Arrays: Computer Simulations. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16093425. [PMID: 37176309 PMCID: PMC10179856 DOI: 10.3390/ma16093425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Revised: 04/09/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023]
Abstract
The paper considers a nanowires 2D array located in the nodes of a square lattice. Computer simulations use the Heisenberg model and Metropolis algorithm. The array consists of small nanowires that are monodomain. The exchange interaction orders the spins within a single nanowire. Dipole-dipole forces act between neighboring nanowires. The shape of an individual nanowire affects its magnetic anisotropy. Computer simulations examine the phase transition temperature and magnetization behavior of the system. The type of magnetic moments ordering in the array of nanowires depends on the orientation of their long axis. We consider two types of systems. The nanowires' long axes are oriented perpendicular to the plane of their location in the first case. A dipole-dipole interaction results in first-type superantiferromagnetic ordering of the nanowires' magnetic moments for such orientation. The nanowires' long axes are oriented in the plane of the system in the second case. Dipole-dipole interaction results in second-type superantiferromagnetic ordering in such systems. The dependence of the phase transition temperature on the dipole-dipole interaction intensity is investigated.
Collapse
Affiliation(s)
- Sergey V Belim
- Department of Physics, Omsk State Technical University, 644050 Omsk, Russia
| | - Igor V Bychkov
- Department of Radiophysics and Electronics, Chelyabinsk State University, 454001 Chelyabinsk, Russia
| |
Collapse
|
5
|
Mohammadalizadeh M, Dabirian S, Akrami M, Hesari Z. SPION based magnetic PLGA nanofibers for neural differentiation of mesenchymal stem cells. NANOTECHNOLOGY 2022; 33:375101. [PMID: 35623211 DOI: 10.1088/1361-6528/ac7402] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Accepted: 05/27/2022] [Indexed: 06/15/2023]
Abstract
Recently, magnetic platforms have been widely investigated in diagnostic, therapeutic and research applications due to certain properties, such as cell and tissue tracking and imaging, thermal therapy and being dirigible. In this study, the incorporation of magnetic nanoparticles (MNPs) in nanofibers has been proposed to combine the advantages of both nanofibers and MNPs to induce neural differentiation of mesenchymal stem cells. Magnetic poly (lactic-co-glycolic acid) nanofibers (containing 0%, 5% and 10% SPION) were fabricated and utilized as the matrix for the differentiation of mesenchymal stem cells (MSCs). Morphological, magnetic and mechanical properties were analyzed using FESEM, VSM and tensile test, respectively. The expression of neural markers (TUJ-1, NSE, MAP-2) was assessed quantitative and qualitatively utilizing RT-PCR and immunocytochemistry. Results confirmed the incorporation of MNPs in nanofibrous scaffold, presenting a saturation magnetization of 9.73 emu g-1. Also, with increase in magnetic particle concentration (0%-10%), tensile strength increased from 4.08 to 5.85 MPa, whereas the percentage of elongation decreased. TUJ-1 expression was 3.8 and 1.8 fold for 10% and 5% magnetic scaffold (versus non-magnetic scaffold) respectively, and the expression of NSE was 6.3 and 1.2-fold for 10% and 5%, respectively. Consequently, it seems that incorporation of magnetic biomaterial can promote the neural differentiation of MSCs, during which the augmentation of super paramagnetic iron oxide concentration from 0% to 10% accelerates the neural differentiation process.
Collapse
Affiliation(s)
- Mahdieh Mohammadalizadeh
- Department of Pharmaceutics, School of Pharmacy, Guilan University of Medical Sciences, Rasht, Iran
| | - Sara Dabirian
- Department of Pharmaceutical Biotechnology, School of Pharmacy, Guilan University of Medical Sciences, Rasht, Iran
| | - Mohammad Akrami
- Department of Pharmaceutical Biomaterials and Medical Biomaterials Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
- Institute of Biomaterials, University of Tehran & Tehran University of Medical Sciences (IBUTUMS), Tehran, Iran
| | - Zahra Hesari
- Department of Pharmaceutics, School of Pharmacy, Guilan University of Medical Sciences, Rasht, Iran
| |
Collapse
|
6
|
Marchal N, da Câmara Santa Clara Gomes T, Abreu Araujo F, Piraux L. Giant Magnetoresistance and Magneto-Thermopower in 3D Interconnected Ni xFe 1-x/Cu Multilayered Nanowire Networks. NANOMATERIALS 2021; 11:nano11051133. [PMID: 33925733 PMCID: PMC8146549 DOI: 10.3390/nano11051133] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/21/2021] [Accepted: 04/24/2021] [Indexed: 11/16/2022]
Abstract
The versatility of the template-assisted electrodeposition technique to fabricate complex three-dimensional networks made of interconnected nanowires allows one to easily stack ferromagnetic and non-magnetic metallic layers along the nanowire axis. This leads to the fabrication of unique multilayered nanowire network films showing giant magnetoresistance effect in the current-perpendicular-to-plane configuration that can be reliably measured along the macroscopic in-plane direction of the films. Moreover, the system also enables reliable measurements of the analogous magneto-thermoelectric properties of the multilayered nanowire networks. Here, three-dimensional interconnected NixFe1−x/Cu multilayered nanowire networks (with 0.60≤x≤0.97) are fabricated and characterized, leading to large magnetoresistance and magneto-thermopower ratios up to 17% and −25% in Ni80Fe20/Cu, respectively. A strong contrast is observed between the amplitudes of magnetoresistance and magneto-thermoelectric effects depending on the Ni content of the NiFe alloys. In particular, for the highest Ni concentrations, a strong increase in the magneto-thermoelectric effect is observed, more than a factor of 7 larger than the magnetoresistive effect for Ni97Fe3/Cu multilayers. This sharp increase is mainly due to an increase in the spin-dependent Seebeck coefficient from −7 µV/K for the Ni60Fe40/Cu and Ni70Fe30/Cu nanowire arrays to −21 µV/K for the Ni97Fe3/Cu nanowire array. The enhancement of the magneto-thermoelectric effect for multilayered nanowire networks based on dilute Ni alloys is promising for obtaining a flexible magnetic switch for thermoelectric generation for potential applications in heat management or logic devices using thermal energy.
Collapse
|
7
|
Magneto-Transport in Flexible 3D Networks Made of Interconnected Magnetic Nanowires and Nanotubes. NANOMATERIALS 2021; 11:nano11010221. [PMID: 33467036 PMCID: PMC7830720 DOI: 10.3390/nano11010221] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 01/07/2021] [Accepted: 01/12/2021] [Indexed: 11/17/2022]
Abstract
Electrochemical deposition of interconnected nanowires and nanotubes made of ferromagnetic metals into track-etched polycarbonate templates with crossed nanochannels has been revealed suitable for the fabrication of mechanically stable three-dimensional magnetic nanostructures with large surface area. These 3D networks embedded into flexible polymer membranes are also planar and lightweight. This fabrication technique allows for the control of the geometric characteristics and material composition of interconnected magnetic nanowire or nanotube networks, which can be used to fine-tune their magnetic and magneto-transport properties. The magnetostatic contribution to the magnetic anisotropy of crossed nanowire networks can be easily controlled using the diameter, packing density, or angle distribution characteristics. Furthermore, the fabrication of Co and Co-rich NiCo alloy crossed nanowires with textured hcp phases leads to an additional significant magnetocrystalline contribution to the magnetic anisotropy that can either compete or add to the magnetostatic contribution. The fabrication of an interconnected nanotube network has also been demonstrated, where the hollow core and the control over the tube wall thickness add another degree of freedom to control the magnetic properties and magnetization reversal mechanisms. Finally, three-dimensional networks made of interconnected multilayered nanowire with a succession of ferromagnetic and non-magnetic layers have been successfully fabricated, leading to giant magnetoresistance responses measured in the current-perpendicular-to-plane configuration. These interconnected nanowire networks have high potential as integrated, reliable, and stable magnetic field sensors; magnetic devices for memory and logic operations; or neuromorphic computing.
Collapse
|
8
|
Yang L, Wang J, Lü H, Hui N. Electrochemical sensor based on Prussian blue/multi-walled carbon nanotubes functionalized polypyrrole nanowire arrays for hydrogen peroxide and microRNA detection. Mikrochim Acta 2021; 188:25. [PMID: 33404773 DOI: 10.1007/s00604-020-04673-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 11/30/2020] [Indexed: 10/22/2022]
Abstract
A dual-sensing platform is proposed based on multi-walled carbon nanotubes/Prussian blue-functionalized polypyrrole nanowire array (PPY/MWCNTs/PB). Highly aligned PPY nanowire arrays were electrochemically prepared on the surface of glassy carbon electrodes, which were doped with MWCNTs/PB nanocomposites. The nanomaterial combines the characteristics of the PPY nanowires (high conductivity and large specific surface area) and MWCNTs/PB (excellent catalytic performance and intrinsic redox activity). Owing to the nanowire microstructure and outstanding electrical properties, the PPY/MWCNTs/PB nanowire arrays show excellent electrocatalysis of the reduction of hydrogen peroxide and facilitate the construction of a high-performance biosensing platform for microRNA (miRNA). A linear relationship between analytical signal and concentration of hydrogen peroxide and miRNA was obtained in the range 5 to 503 µM (1.4-5.1 mM) and 0.1 pM to 1 nM, and detection limits of 1.7 μM and 33.4 fM, respectively. This new supersensitive sensing platform has broad application prospects of biomolecule and other analyte determination in drug, biomedical, plant protection, and environmental analysis. Prussian blue/multi-walled carbon nanotubes functionalized polypyrrole nanowire arrays (PPY/MWCNTs/PB) were prepared by a facile one-step electrochemical method. PPY/MWCNTs/PB nanowire arrays show excellent electrocatalysis of the reduction of H2O2 and facilitate the construction of a high-performance biosensing platform for microRNA.
Collapse
Affiliation(s)
- Lili Yang
- College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao, 266109, China
| | - Jiasheng Wang
- College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao, 266109, China
| | - Haitao Lü
- College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao, 266109, China
| | - Ni Hui
- College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao, 266109, China.
| |
Collapse
|
9
|
Spin Caloritronics in 3D Interconnected Nanowire Networks. NANOMATERIALS 2020; 10:nano10112092. [PMID: 33105666 PMCID: PMC7690391 DOI: 10.3390/nano10112092] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 10/15/2020] [Accepted: 10/19/2020] [Indexed: 12/03/2022]
Abstract
Recently, interconnected nanowire networks have been found suitable as flexible macroscopic spin caloritronic devices. The 3D nanowire networks are fabricated by direct electrodeposition in track-etched polymer templates with crossed nano-channels. This technique allows the fabrication of crossed nanowires consisting of both homogeneous ferromagnetic metals and multilayer stack with successive layers of ferromagnetic and non-magnetic metals, with controlled morphology and material composition. The networks exhibit extremely high, magnetically modulated thermoelectric power factors. Moreover, large spin-dependent Seebeck coefficients were directly extracted from experimental measurements on multilayer nanowire networks. This work provides a simple and cost-effective way to fabricate large-scale flexible and shapeable thermoelectric devices exploiting the spin degree of freedom.
Collapse
|
10
|
Marchal N, da Câmara Santa Clara Gomes T, Abreu Araujo F, Piraux L. Large Spin-Dependent Thermoelectric Effects in NiFe-based Interconnected Nanowire Networks. NANOSCALE RESEARCH LETTERS 2020; 15:137. [PMID: 32602034 PMCID: PMC7324447 DOI: 10.1186/s11671-020-03343-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 05/06/2020] [Indexed: 06/09/2023]
Abstract
NiFe alloy and NiFe/Cu multilayered nanowire (NW) networks were grown using a template-assisted electrochemical synthesis method. The NiFe alloy NW networks exhibit large thermopower, which is largely preserved in the current perpendicular-to-plane geometry of the multilayered NW structure. Giant magneto-thermopower (MTP) effects have been demonstrated in multilayered NiFe/Cu NWs with a value of 25% at 300 K and reaching 60% around 100 K. A large spin-dependent Seebeck coefficient of -12.3 μV/K was obtained at room temperature. The large MTP effects demonstrate a magnetic approach to control thermoelectric properties of flexible devices based on NW networks.
Collapse
Affiliation(s)
- Nicolas Marchal
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Place Croix du Sud 1, Louvain-la-Neuve, 1348, Belgium
| | | | - Flavio Abreu Araujo
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Place Croix du Sud 1, Louvain-la-Neuve, 1348, Belgium
| | - Luc Piraux
- Institute of Condensed Matter and Nanosciences, Université catholique de Louvain, Place Croix du Sud 1, Louvain-la-Neuve, 1348, Belgium.
| |
Collapse
|
11
|
Abstract
Magnetic nanowires are attractive materials because of their morphology-dependent remarkable properties suitable for various advanced technologies in sensing, data storage, spintronics, biomedicine and microwave devices, etc. The recent advances in synthetic strategies and approaches for the fabrication of complex structures, such as parallel arrays and 3D networks of one-dimensional nanostructures, including nanowires, nanotubes, and multilayers, are presented. The simple template-assisted electrodeposition method enables the fabrication of different nanowire-based architectures with excellent control over geometrical features, morphology and chemical composition, leading to tunable magnetic, magneto-transport and thermoelectric properties. This review article summarizing the work carried out at UCLouvain focuses on the magnetic and spin-dependent transport properties linked to the material and geometrical characteristics.
Collapse
|
12
|
da Câmara Santa Clara Gomes T, Abreu Araujo F, Piraux L. Making flexible spin caloritronic devices with interconnected nanowire networks. SCIENCE ADVANCES 2019; 5:eaav2782. [PMID: 30838330 PMCID: PMC6397025 DOI: 10.1126/sciadv.aav2782] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 01/11/2019] [Indexed: 05/27/2023]
Abstract
Spin caloritronics has recently emerged from the combination of spintronics and thermoelectricity. Here, we show that flexible, macroscopic spin caloritronic devices based on large-area interconnected magnetic nanowire networks can be used to enable controlled Peltier cooling of macroscopic electronic components with an external magnetic field. We experimentally demonstrate that three-dimensional CoNi/Cu multilayered nanowire networks exhibit an extremely high, magnetically modulated thermoelectric power factor up to 7.5 mW/K2m and large spin-dependent Seebeck and Peltier coefficients of -11.5 μV/K and -3.45 mV at room temperature, respectively. Our investigation reveals the possibility of performing efficient magnetic control of heat flux for thermal management of electronic devices and constitutes a simple and cost-effective pathway for fabrication of large-scale flexible and shapeable thermoelectric coolers exploiting the spin degree of freedom.
Collapse
|
13
|
Akin M, Pratt A, Blackburn J, Dietzel A. Paper-Based Magneto-Resistive Sensor: Modeling, Fabrication, Characterization, and Application. SENSORS 2018; 18:s18124392. [PMID: 30545031 PMCID: PMC6308649 DOI: 10.3390/s18124392] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 11/29/2018] [Accepted: 12/10/2018] [Indexed: 11/16/2022]
Abstract
In this work, we developed and fabricated a paper-based anisotropic magneto-resistive sensor using a sputtered permalloy (Ni81Fe19) thin film. To interpret the characteristics of the sensor, we proposed a computational model to capture the influence of the stochastic fiber network of the paper surface and to explain the physics behind the empirically observed difference in paper-based anisotropic magneto-resistance (AMR). Using the model, we verified two main empirical observations: (1) The stochastic fiber network of the paper substrate induces a shift of 45∘ in the AMR response of the paper-based Ni81Fe19 thin film compared to a Ni81Fe19 film on a smooth surface as long as the fibrous topography has not become buried. (2) The ratio of magnitudes of AMR peaks at different anisotropy angles and the inverted AMR peak at the 90∘-anisotropy angle are explained through the superposition of the responses of Ni81Fe19 inheriting the fibrous topography and smoother Ni81Fe19 on buried fibrous topographies. As for the sensitivity and reproducibility of the sensor signal, we obtained a maximum AMR peak of 0.4%, min-max sensitivity range of [0.17,0.26]%, average asymmetry of peak location of 2.7kAm within two consecutive magnetic loading cycles, and a deviation of 250–850 Am of peak location across several anisotropy angles at a base resistance of ∼100 Ω. Last, we demonstrated the usability of the sensor in two educational application examples: a textbook clicker and interactive braille flashcards.
Collapse
Affiliation(s)
- Meriem Akin
- Institute of Microtechnology, Department of Mechanical Engineering, Braunschweig University of Technology, 38124 Braunschweig, Germany.
| | - Autumn Pratt
- Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14853, USA.
| | - Jennifer Blackburn
- School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907, USA.
| | - Andreas Dietzel
- Institute of Microtechnology, Department of Mechanical Engineering, Braunschweig University of Technology, 38124 Braunschweig, Germany.
| |
Collapse
|
14
|
Abstract
Combining 1D metal nanotubes and nanowires into cross-linked 2D and 3D architectures represents an attractive design strategy for creating tailored unsupported catalysts. Such materials complement the functionality and high surface area of the nanoscale building blocks with the stability, continuous conduction pathways, efficient mass transfer, and convenient handling of a free-standing, interconnected, open-porous superstructure. This review summarizes synthetic approaches toward metal nano-networks of varying dimensionality, including the assembly of colloidal 1D nanostructures, the buildup of nanofibrous networks by electrospinning, and direct, template-assisted deposition methods. It is outlined how the nanostructure, porosity, network architecture, and composition of such materials can be tuned by the fabrication conditions and additional processing steps. Finally, it is shown how these synthetic tools can be employed for designing and optimizing self-supported metal nano-networks for application in electrocatalysis and related fields.
Collapse
|
15
|
Ni-Co Alloy and Multisegmented Ni/Co Nanowire Arrays Modulated in Composition: Structural Characterization and Magnetic Properties. CRYSTALS 2017. [DOI: 10.3390/cryst7030066] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|