1
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Fumega AO, Lado JL. Nature of the Unconventional Heavy-Fermion Kondo State in Monolayer CeSiI. Nano Lett 2024; 24:4272-4278. [PMID: 38394370 PMCID: PMC11010227 DOI: 10.1021/acs.nanolett.4c00619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Revised: 02/14/2024] [Accepted: 02/15/2024] [Indexed: 02/25/2024]
Abstract
CeSiI has been recently isolated in the ultrathin limit, establishing CeSiI as the first intrinsic two-dimensional van der Waals heavy-fermion material up to 85 K. We show that, due to the strong spin-orbit coupling, the local moments develop a multipolar real-space magnetic texture, leading to local pseudospins with a nearly vanishing net moment. To elucidate its Kondo-screened regime, we extract from first-principles the parameters of the Kondo lattice model describing this material. We develop a pseudofermion methodology in combination with ab initio calculations to reveal the nature of the heavy-fermion state in CeSiI. We analyze the competing magnetic interactions leading to an unconventional heavy-fermion order as a function of the magnetic exchange between the localized f-electrons and the strength of the Kondo coupling. Our results show that the magnetic exchange interactions promote an unconventional momentum-dependent Kondo-screened phase, establishing the nature of the heavy-fermion state observed in CeSiI.
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Affiliation(s)
- Adolfo O. Fumega
- Department of Applied
Physics, Aalto University, 02150 Espoo, Finland
| | - Jose L. Lado
- Department of Applied
Physics, Aalto University, 02150 Espoo, Finland
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2
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Patrian M, Shaukat A, Nieddu M, Banda-Vázquez JA, Timonen JVI, Fuenzalida Werner JP, Anaya-Plaza E, Kostiainen MA, Costa RD. Supercharged Fluorescent Protein-Apoferritin Cocrystals for Lighting Applications. ACS Nano 2023; 17:21206-21215. [PMID: 37902649 PMCID: PMC10684032 DOI: 10.1021/acsnano.3c05284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 10/12/2023] [Indexed: 10/31/2023]
Abstract
The application of fluorescent proteins (FPs) in optoelectronics is hindered by the need for effective protocols to stabilize them under device preparation and operational conditions. Factors such as high temperatures, irradiation, and organic solvent exposure contribute to the denaturation of FPs, resulting in a low device performance. Herein, we focus on addressing the photoinduced heat generation associated with FP motion and rapid heat transfer. This leads to device temperatures of approximately 65 °C, causing FP-denaturation and a subsequent loss of device functionality. We present a FP stabilization strategy involving the integration of electrostatically self-assembled FP-apoferritin cocrystals within a silicone-based color down-converting filter. Three key achievements characterize this approach: (i) an engineering strategy to design positively supercharged FPs (+22) without compromising photoluminescence and thermal stability compared to their native form, (ii) a carefully developed crystallization protocol resulting in highly emissive cocrystals that retain the essential photoluminescence features of the FPs, and (iii) a strong reduction of the device's working temperature to 40 °C, leading to a 40-fold increase in Bio-HLEDs stability compared to reference devices.
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Affiliation(s)
- Marta Patrian
- Chair
of Biogenic Functional Materials, 6 Technical
University of Munich, Schulgasse, 22, Straubing 94315, Germany
| | - Ahmed Shaukat
- Department
of Bioproducts and Biosystems, Aalto University, 00076 Aalto, Finland
| | - Mattia Nieddu
- Chair
of Biogenic Functional Materials, 6 Technical
University of Munich, Schulgasse, 22, Straubing 94315, Germany
| | - Jesús Agustín Banda-Vázquez
- Chair
of Biogenic Functional Materials, 6 Technical
University of Munich, Schulgasse, 22, Straubing 94315, Germany
| | - Jaakko V. I. Timonen
- Department
of Applied Physics, Aalto University School
of Science, P.O. Box 15100, Espoo FI-02150, Finland
| | - Juan Pablo Fuenzalida Werner
- Chair
of Biogenic Functional Materials, 6 Technical
University of Munich, Schulgasse, 22, Straubing 94315, Germany
| | - Eduardo Anaya-Plaza
- Department
of Bioproducts and Biosystems, Aalto University, 00076 Aalto, Finland
| | - Mauri A. Kostiainen
- Department
of Bioproducts and Biosystems, Aalto University, 00076 Aalto, Finland
| | - Rubén D. Costa
- Chair
of Biogenic Functional Materials, 6 Technical
University of Munich, Schulgasse, 22, Straubing 94315, Germany
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3
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Bansfield D, Spilling K, Mikola A, Piiparinen J. Growth of fungi and yeasts in food production waste streams: a feasibility study. BMC Microbiol 2023; 23:328. [PMID: 37926808 PMCID: PMC10626767 DOI: 10.1186/s12866-023-03083-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 10/23/2023] [Indexed: 11/07/2023] Open
Abstract
Food production produces nutrient-rich waste streams which, depending on local legislation, are either sent to wastewater treatment plants or discharged into the environment. In addition to causing environmental harm in the second instance, valuable nutrients are lost. A more circular approach would be to reuse these waste streams. Fungi and yeasts are ideal candidates as they require lots of organic carbon (which is especially high in food production waste streams) for growth, with the potential for producing value-added biomass. Here, we tested the metabolic activity and possible growth of seven fungi and three yeasts in five different food production waste streams. Initial tests were done to find the most promising waste streams for growth and these were chosen for further study. All species were then cultured in these waste streams and oxygen uptake was measured to gauge metabolic activity which we used as a proxy for growth rate. Pelletization's effect on metabolic rates was tested on the most pellet-forming species, by adding agar to inhibit pellet formation. The most promising waste stream for yeast/fungal growth was cheese whey (Whey). Pellet inhibition (i.e., filamentous growth) resulted in increased metabolic activity of cells in the confectionary bakery waste stream with agar but decreased metabolic activity in Whey with agar. The best-growing species, Geotrichum candidum, has potential commercial value as a producer of enzymes, biochemicals and lipids and could provide added value while improving the circularity of water and nutrients in food production.
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Affiliation(s)
- D Bansfield
- Marine and Freshwater Solutions, Finnish Environment Institute, Agnes Sjöbergin katu 2, Helsinki, 00790, Finland.
- Department of Built Environment, Aalto University, Tietotie 1E, Espoo, 00076, Finland.
| | - K Spilling
- Marine and Freshwater Solutions, Finnish Environment Institute, Agnes Sjöbergin katu 2, Helsinki, 00790, Finland
- Centre for Coastal Research, University of Agder, Universitetsveien 25, Kristiansand, 4630, Norway
| | - A Mikola
- Department of Built Environment, Aalto University, Tietotie 1E, Espoo, 00076, Finland
| | - J Piiparinen
- Marine and Freshwater Solutions, Finnish Environment Institute, Agnes Sjöbergin katu 2, Helsinki, 00790, Finland
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4
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Wang Y, Iyikanat F, Bai X, Hu X, Das S, Dai Y, Zhang Y, Du L, Li S, Lipsanen H, García de Abajo FJ, Sun Z. Optical Control of High-Harmonic Generation at the Atomic Thickness. Nano Lett 2022; 22:8455-8462. [PMID: 36305718 PMCID: PMC9650768 DOI: 10.1021/acs.nanolett.2c02711] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 10/14/2022] [Indexed: 06/16/2023]
Abstract
High-harmonic generation (HHG), an extreme nonlinear optical phenomenon beyond the perturbation regime, is of great significance for various potential applications, such as high-energy ultrashort pulse generation with outstanding spatiotemporal coherence. However, efficient active control of HHG is still challenging due to the weak light-matter interaction displayed by currently known materials. Here, we demonstrate optically controlled HHG in monolayer semiconductors via the engineering of interband polarization. We find that HHG can be efficiently controlled in the excitonic spectral region with modulation depths up to 95% and ultrafast response speeds of several picoseconds. Quantitative time-domain theory of the nonlinear optical susceptibilities in monolayer semiconductors further corroborates these experimental observations. Our demonstration not only offers an in-depth understanding of HHG but also provides an effective approach toward active optical devices for strong-field physics and extreme nonlinear optics.
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Affiliation(s)
- Yadong Wang
- Department
of Electronics and Nanoengineering, Aalto
University, Espoo02150, Finland
| | - Fadil Iyikanat
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute
of Science and Technology, 08860Castelldefels, Barcelona, Spain
| | - Xueyin Bai
- Department
of Electronics and Nanoengineering, Aalto
University, Espoo02150, Finland
| | - Xuerong Hu
- Department
of Electronics and Nanoengineering, Aalto
University, Espoo02150, Finland
- International
Cooperation Base of Photoelectric Technology and Functional Materials,
and Institute of Photonics and Photon-Technology, Northwest University, Xi’an710069, China
| | - Susobhan Das
- Department
of Electronics and Nanoengineering, Aalto
University, Espoo02150, Finland
| | - Yunyun Dai
- Department
of Electronics and Nanoengineering, Aalto
University, Espoo02150, Finland
| | - Yi Zhang
- Department
of Electronics and Nanoengineering, Aalto
University, Espoo02150, Finland
| | - Luojun Du
- Department
of Electronics and Nanoengineering, Aalto
University, Espoo02150, Finland
| | - Shisheng Li
- WPI
International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba305-0044, Japan
| | - Harri Lipsanen
- Department
of Electronics and Nanoengineering, Aalto
University, Espoo02150, Finland
| | - F. Javier García de Abajo
- ICFO-Institut
de Ciencies Fotoniques, The Barcelona Institute
of Science and Technology, 08860Castelldefels, Barcelona, Spain
- ICREA-Institució
Catalana de Recerca i Estudis Avançats, Passeig Lluís Companys 23, 08010Barcelona, Spain
| | - Zhipei Sun
- Department
of Electronics and Nanoengineering, Aalto
University, Espoo02150, Finland
- QTF Centre
of Excellence, Department of Applied Physics, Aalto University, Espoo02150, Finland
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5
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Shafi AM, Ahmed F, Fernandez HA, Uddin MG, Cui X, Das S, Dai Y, Khayrudinov V, Yoon HH, Du L, Sun Z, Lipsanen H. Inducing Strong Light-Matter Coupling and Optical Anisotropy in Monolayer MoS 2 with High Refractive Index Nanowire. ACS Appl Mater Interfaces 2022; 14:31140-31147. [PMID: 35763802 PMCID: PMC9284513 DOI: 10.1021/acsami.2c07705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Mixed-dimensional heterostructures combine the merits of materials of different dimensions; therefore, they represent an advantageous scenario for numerous technological advances. Such an approach can be exploited to tune the physical properties of two-dimensional (2D) layered materials to create unprecedented possibilities for anisotropic and high-performance photonic and optoelectronic devices. Here, we report a new strategy to engineer the light-matter interaction and symmetry of monolayer MoS2 by integrating it with one-dimensional (1D) AlGaAs nanowire (NW). Our results show that the photoluminescence (PL) intensity of MoS2 increases strongly in the mixed-dimensional structure because of electromagnetic field confinement in the 1D high refractive index semiconducting NW. Interestingly, the 1D NW breaks the 3-fold rotational symmetry of MoS2, which leads to a strong optical anisotropy of up to ∼60%. Our mixed-dimensional heterostructure-based phototransistors benefit from this and exhibit an improved optoelectronic device performance with marked anisotropic photoresponse behavior. Compared with bare MoS2 devices, our MoS2/NW devices show ∼5 times enhanced detectivity and ∼3 times higher photoresponsivity. Our results of engineering light-matter interaction and symmetry breaking provide a simple route to induce enhanced and anisotropic functionalities in 2D materials.
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Affiliation(s)
- Abde Mayeen Shafi
- Department
of Electronics and Nanoengineering, Aalto
University, Tietotie 3, Espoo FI-02150, Finland
| | - Faisal Ahmed
- Department
of Electronics and Nanoengineering, Aalto
University, Tietotie 3, Espoo FI-02150, Finland
| | - Henry A. Fernandez
- Department
of Electronics and Nanoengineering, Aalto
University, Tietotie 3, Espoo FI-02150, Finland
- QTF
Centre of Excellence, Department of Applied Physics, Aalto University, Aalto FI-00076, Finland
| | - Md Gius Uddin
- Department
of Electronics and Nanoengineering, Aalto
University, Tietotie 3, Espoo FI-02150, Finland
| | - Xiaoqi Cui
- Department
of Electronics and Nanoengineering, Aalto
University, Tietotie 3, Espoo FI-02150, Finland
| | - Susobhan Das
- Department
of Electronics and Nanoengineering, Aalto
University, Tietotie 3, Espoo FI-02150, Finland
| | - Yunyun Dai
- Department
of Electronics and Nanoengineering, Aalto
University, Tietotie 3, Espoo FI-02150, Finland
| | - Vladislav Khayrudinov
- Department
of Electronics and Nanoengineering, Aalto
University, Tietotie 3, Espoo FI-02150, Finland
| | - Hoon Hahn Yoon
- Department
of Electronics and Nanoengineering, Aalto
University, Tietotie 3, Espoo FI-02150, Finland
| | - Luojun Du
- Department
of Electronics and Nanoengineering, Aalto
University, Tietotie 3, Espoo FI-02150, Finland
| | - Zhipei Sun
- Department
of Electronics and Nanoengineering, Aalto
University, Tietotie 3, Espoo FI-02150, Finland
- QTF
Centre of Excellence, Department of Applied Physics, Aalto University, Aalto FI-00076, Finland
| | - Harri Lipsanen
- Department
of Electronics and Nanoengineering, Aalto
University, Tietotie 3, Espoo FI-02150, Finland
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6
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Abstract
Plasmonic lattices of metal nanoparticles have emerged as an effective platform for strong light-matter coupling, lasing, and Bose-Einstein condensation. However, the full potential of complex unit cell structures has not been exploited. On the other hand, bound states in continuum (BICs) have attracted attention, as they provide topologically protected optical modes with diverging quality factors. Here, we show that quadrumer nanoparticle lattices enable lasing in a quasi-BIC mode with a highly out-of-plane character. By combining theory with polarization-resolved measurements of the emission, we show that the lasing mode has a topological charge. Our analysis reveals that the mode is primarily polarized out-of-plane as a result of the quadrumer structure. The quality factors of the out-of-plane BIC modes of the quadrumer array can be exceedingly high. Our results unveil the power of complex multiparticle unit cells in creating topologically protected high-Q modes in periodic nanostructures.
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Affiliation(s)
- Rebecca Heilmann
- Department
of Applied Physics, Aalto University School
of Science, P.O. Box 15 100, Aalto, FI-00 076, Finland
| | - Grazia Salerno
- Department
of Applied Physics, Aalto University School
of Science, P.O. Box 15 100, Aalto, FI-00 076, Finland
| | - Javier Cuerda
- Department
of Applied Physics, Aalto University School
of Science, P.O. Box 15 100, Aalto, FI-00 076, Finland
| | - Tommi K. Hakala
- Institute
of Photonics, University of Eastern Finland, FI-80 101 Joensuu, Finland
| | - Päivi Törmä
- Department
of Applied Physics, Aalto University School
of Science, P.O. Box 15 100, Aalto, FI-00 076, Finland
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7
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Huertas ZC, Settipani D, Flox C, Morante JR, Kallio T, Biendicho JJ. High performance silicon electrode enabled by titanicone coating. Sci Rep 2022; 12:137. [PMID: 34997066 PMCID: PMC8741799 DOI: 10.1038/s41598-021-04105-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 12/06/2021] [Indexed: 12/22/2022] Open
Abstract
This paper presents the electrochemical performance and characterization of nano Si electrodes coated with titanicone (TiGL) as an anode for Li ion batteries (LIBs). Atomic layer deposition (ALD) of the metal combined with the molecular layer deposition (MLD) of the organic precursor is used to prepare coated electrodes at different temperatures with improved performance compared to the uncoated Si electrode. Coated electrodes prepared at 150 °C deliver the highest capacity and best current response of 1800 mAh g-1 at 0.1 C and 150 mAh g-1 at 20 C. This represented a substantial improvement compared to the Si baseline which delivers a capacity of 1100 mAh g-1 at 0.1 C but fails to deliver capacity at 20 C. Moreover, the optimized coated electrode shows an outstanding capacity of 1200 mAh g-1 at 1 C for 350 cycles with a capacity retention of 93%. The improved discharge capacity, electrode efficiencies, rate capability and electrochemical stability for the Si-based electrode presented in this manuscript are directly correlated to the optimized TiGL coating layer deposited by the ALD/MLD processes, which enhances lithium kinetics and electronic conductivity as demonstrated by equivalent circuit analysis of low frequency impedance data and conductivity measurements. The coating strategy also stabilizes SEI film formation with better Coulombic efficiencies (CE) and improves long cycling stability by reducing capacity lost.
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Affiliation(s)
- Zahilia Cabán Huertas
- Aalto University, Kemistintie 1, 02150, Espoo, Finland
- Catalonia Institute for Energy Research, Jardins de les Dones de Negre 1, 2ª p., 08930, Barcelona, Spain
| | | | - Cristina Flox
- Aalto University, Kemistintie 1, 02150, Espoo, Finland
| | - Joan Ramon Morante
- Catalonia Institute for Energy Research, Jardins de les Dones de Negre 1, 2ª p., 08930, Barcelona, Spain
- Faculty of Physics, University of Barcelona, Marti I Franques, 1, 08028, Barcelona, Spain
| | - Tanja Kallio
- Aalto University, Kemistintie 1, 02150, Espoo, Finland.
| | - Jordi Jacas Biendicho
- Catalonia Institute for Energy Research, Jardins de les Dones de Negre 1, 2ª p., 08930, Barcelona, Spain.
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8
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Tugin S, Souza VH, Nazarova MA, Novikov PA, Tervo AE, Nieminen JO, Lioumis P, Ziemann U, Nikulin VV, Ilmoniemi RJ. Effect of stimulus orientation and intensity on short-interval intracortical inhibition (SICI) and facilitation (SICF): A multi-channel transcranial magnetic stimulation study. PLoS One 2021; 16:e0257554. [PMID: 34550997 PMCID: PMC8457500 DOI: 10.1371/journal.pone.0257554] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 09/03/2021] [Indexed: 11/18/2022] Open
Abstract
Besides stimulus intensities and interstimulus intervals (ISI), the electric field (E-field) orientation is known to affect both short-interval intracortical inhibition (SICI) and facilitation (SICF) in paired-pulse transcranial magnetic stimulation (TMS). However, it has yet to be established how distinct orientations of the conditioning (CS) and test stimuli (TS) affect the SICI and SICF generation. With the use of a multi-channel TMS transducer that provides electronic control of the stimulus orientation and intensity, we aimed to investigate how changes in the CS and TS orientation affect the strength of SICI and SICF. We hypothesized that the CS orientation would play a major role for SICF than for SICI, whereas the CS intensity would be more critical for SICI than for SICF. In eight healthy subjects, we tested two ISIs (1.5 and 2.7 ms), two CS and TS orientations (anteromedial (AM) and posteromedial (PM)), and four CS intensities (50, 70, 90, and 110% of the resting motor threshold (RMT)). The TS intensity was fixed at 110% RMT. The intensities were adjusted to the corresponding RMT in the AM and PM orientations. SICI and SICF were observed in all tested CS and TS orientations. SICI depended on the CS intensity in a U-shaped manner in any combination of the CS and TS orientations. With 70% and 90% RMT CS intensities, stronger PM-oriented CS induced stronger inhibition than weaker AM-oriented CS. Similar SICF was observed for any CS orientation. Neither SICI nor SICF depended on the TS orientation. We demonstrated that SICI and SICF could be elicited by the CS perpendicular to the TS, which indicates that these stimuli affected either overlapping or strongly connected neuronal populations. We concluded that SICI is primarily sensitive to the CS intensity and that CS intensity adjustment resulted in similar SICF for different CS orientations.
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Affiliation(s)
- Sergei Tugin
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
- BioMag Laboratory, University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Centre, Helsinki, Finland
- * E-mail:
| | - Victor H. Souza
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
- BioMag Laboratory, University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Centre, Helsinki, Finland
- School of Physiotherapy, Federal University of Juiz de Fora, Juiz de Fora, MG, Brazil
| | - Maria A. Nazarova
- Centre for Cognition and Decision Making, Institute for Cognitive Neuroscience, National Research University Higher School of Economics, Moscow, Russia
- Federal State Budgetary Institution “Federal Center of Brain Research and Neurotechnologies” of the Federal Medical Biological Agency, Moscow, Russia
| | - Pavel A. Novikov
- Centre for Cognition and Decision Making, Institute for Cognitive Neuroscience, National Research University Higher School of Economics, Moscow, Russia
| | - Aino E. Tervo
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
- BioMag Laboratory, University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Centre, Helsinki, Finland
| | - Jaakko O. Nieminen
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
- BioMag Laboratory, University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Centre, Helsinki, Finland
| | - Pantelis Lioumis
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
- BioMag Laboratory, University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Centre, Helsinki, Finland
| | - Ulf Ziemann
- Department of Neurology and Stroke, Eberhard Karls University, Tübingen, Germany
- Hertie Institute for Clinical Brain Research, Eberhard Karls University, Tübingen, Germany
| | - Vadim V. Nikulin
- Centre for Cognition and Decision Making, Institute for Cognitive Neuroscience, National Research University Higher School of Economics, Moscow, Russia
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Risto J. Ilmoniemi
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
- BioMag Laboratory, University of Helsinki and Helsinki University Hospital, HUS Medical Imaging Centre, Helsinki, Finland
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9
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Greca LG, De France KJ, Majoinen J, Kummer N, Luotonen OIV, Campioni S, Rojas OJ, Nyström G, Tardy BL. Chitin-amyloid synergism and their use as sustainable structural adhesives. J Mater Chem A Mater 2021; 9:19741-19753. [PMID: 34589225 PMCID: PMC8439147 DOI: 10.1039/d1ta03215a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 06/29/2021] [Indexed: 05/28/2023]
Abstract
Structural adhesives are relevant to many engineering applications, especially those requiring load-bearing joints with high lap shear strength. Typical adhesives are synthesized from acrylics, epoxies, or urethanes, which may pose a burden to sustainability and the environment. In nature, the interfacial interactions between chitin and proteins are used for structural purposes and as a bio-cement, resulting in materials with properties unmatched by their man-made counterparts. Herein, we show that related supramolecular interactions can be harnessed to develop high strength green adhesives based on chitin nanocrystals (ChNCs), isolated from shrimp shells, and hen egg white lysozyme (HEWL) used in its monomeric or amyloid forms. Consolidation of the bicomponent suspensions, placed between glass substrates, results in long-range ordered superstructures. The formation of these structures is evaluated by surface energy considerations, followed by scanning electron, atomic force, and polarized microscopies of the consolidated materials. For 0.8 mg of bio-adhesive (lysozyme, ChNCs or their composites), lap shear loads of over 300 N are reached. Such remarkable adhesion reaches maximum values at protein-to-ChNC ratios below 1 : 4, reflecting the synergy established between the components (ca. 25% higher load compared to ChNCs, the strongest single component). We put the observed adhesive performance in perspective by comparing the lap-shear performance with current research on green supramolecular adhesives using natural biopolymers. The results are discussed in the context of current efforts to standardize the measurement of adhesive strength and bond preparation. The latter is key to formalizing the metrology and materials chemistry of bio-based adhesives. The proposed all-green system is expected to expand current developments in the design of bio-based adhesives.
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Affiliation(s)
- Luiz G Greca
- Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University P. O. Box 16300 FI-00076 AALTO Finland
| | - Kevin J De France
- Laboratory for Cellulose & Wood Materials, Empa - Swiss Federal Laboratories for Materials Science and Technology Überlandstrasse 129 8600 Dübendorf Switzerland
| | - Johanna Majoinen
- Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University P. O. Box 16300 FI-00076 AALTO Finland
| | - Nico Kummer
- Laboratory for Cellulose & Wood Materials, Empa - Swiss Federal Laboratories for Materials Science and Technology Überlandstrasse 129 8600 Dübendorf Switzerland
- Department of Health Science and Technology, ETH Zürich 8092 Zürich Switzerland
| | - Otso I V Luotonen
- Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University P. O. Box 16300 FI-00076 AALTO Finland
| | - Silvia Campioni
- Laboratory for Cellulose & Wood Materials, Empa - Swiss Federal Laboratories for Materials Science and Technology Überlandstrasse 129 8600 Dübendorf Switzerland
| | - Orlando J Rojas
- Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University P. O. Box 16300 FI-00076 AALTO Finland
- Bioproducts Institute, Department of Chemical and Biological Engineering, Department of Chemistry and Department of Wood Science, University of British Columbia 2360 East Mall Vancouver BC V6T 1Z4 Canada
| | - Gustav Nyström
- Laboratory for Cellulose & Wood Materials, Empa - Swiss Federal Laboratories for Materials Science and Technology Überlandstrasse 129 8600 Dübendorf Switzerland
- Department of Health Science and Technology, ETH Zürich 8092 Zürich Switzerland
| | - Blaise L Tardy
- Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University P. O. Box 16300 FI-00076 AALTO Finland
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10
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Kaaos J, Ross G, Paulasto-Kröckel M. Aluminum Nitride to Silicon Direct Bonding for an Alternative Silicon-On-Insulator Platform. ACS Appl Mater Interfaces 2021; 13:38857-38865. [PMID: 34347425 PMCID: PMC8397240 DOI: 10.1021/acsami.1c09535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 07/22/2021] [Indexed: 05/25/2023]
Abstract
The next generation of microelectromechanical systems (MEMS) requires new materials and platforms that can exploit the intrinsic properties of advanced materials and structures, such as materials with high thermal conductivity, broad optical transmission spectra, piezoelectric properties, and miniaturization potential. Therefore, we need to look beyond standard SiO2-based silicon-on-insulator (SOI) structures to realize ubiquitous MEMS. This work proposes using AlN as an alternative SOI structure due to several inherent material property advantages as well as functional advantages. This work presents the results of reactively sputtered AlN films on a Si handle wafer bonded with a mirror-polished Si device wafer. Wafer bonding was achieved by using hydrophilic wafer bonding processes, which was realized by appropriate polymerization of the prebonding surfaces. Plasma activation of the AlN surface included O2, Ar, SF6, SF6 + Ar, and/or SF6 + O2, which resulted in a change in the chemical and topography state of the surface. Changes in the AlN surface properties included enhanced hydrophilicity, reduced surface roughness, and low nanotopography, components essential for successful hydrophilic direct wafer bonding. Wafer bonding experiments were carried out using promising surface activation methods. The results showed a multilayered bonding interface of Si(Device)/SiO2/ALON/AlN/Si(Handle) with fluorine in the aluminum oxynitride layer from the proceeding AlN surface activation process. More notably, this work provided wafer bonding tensile strength results of the AlN alternative SOI structure that compares with the traditional SiO2 SOI counterpart, making AlN to Si direct bonding an attractive alternative SOI platform.
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Henn KA, Forsman N, Zou T, Österberg M. Colloidal Lignin Particles and Epoxies for Bio-Based, Durable, and Multiresistant Nanostructured Coatings. ACS Appl Mater Interfaces 2021; 13:34793-34806. [PMID: 34261310 PMCID: PMC8397241 DOI: 10.1021/acsami.1c06087] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
There is a need for safe and sustainable alternatives in the coating industry. Bio-based coatings are interesting in this perspective. Although various oils and waxes have been used as traditional wood coatings, they often lack sufficient durability. Lignin is an abundant natural polyphenol that can be used to cure epoxies, but its poor water solubility has impeded the use of unmodified lignin in coatings in the past. To address this issue, water-dispersible colloidal lignin particles (CLPs) and an epoxy compound, glycerol diglycidyl ether (GDE), were used to prepare multiprotective bio-based surface coatings. With the GDE/CLP ratios of 0.65 and 0.52 g/g, the cured CLP-GDE films became highly resistant to abrasion and heat. When applied as a coating on wooden substrates, the particulate morphology enabled effective protection against water, stains, and sunlight with very thin layers (less than half the weight of commercial coatings) while retaining the wood's breathability excellently. Optimal hydrophobicity was reached with a coat weight of 6.9 g(CLP)/m2, resulting in water contact angle values of up to 120°. Due to their spherical shape and chemical structure, the CLPs acted as both a hardener and a particulate component in the coating, which removed the need for an underlying binding polymer matrix. Light interferometry measurements showed that while commercial polymeric film-forming coatings smoothened the substrate noticeably, the particulate morphology retained the substrate's roughness in lightweight coatings, allowing for a high water contact angle. This work presents new strategies for lignin applications in durable particulate coatings and their advantages compared to both currently used synthetic and bio-based coatings.
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Tzoulas K, Galan J, Venn S, Dennis M, Pedroli B, Mishra H, Haase D, Pauleit S, Niemelä J, James P. A conceptual model of the social-ecological system of nature-based solutions in urban environments. Ambio 2021; 50:335-345. [PMID: 32915446 PMCID: PMC7782638 DOI: 10.1007/s13280-020-01380-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 11/22/2019] [Accepted: 08/08/2020] [Indexed: 05/18/2023]
Abstract
This article provides a perspective on nature-based solutions. First, the argument is developed that nature-based solutions integrate social and ecological systems. Then, theoretical considerations relating to relational values, multifunctionality, transdisciplinarity, and polycentric governance are briefly outlined. Finally, a conceptual model of the social-ecological system of nature-based solutions is synthesised and presented. This conceptual model comprehensively defines the social and ecological external and internal systems that make up nature-based solutions, and identifies theoretical considerations that need to be addressed at different stages of their planning and implementation The model bridges the normative gaps of existing nature-based solution frameworks and could be used for consistent, comprehensive, and transferable comparisons internationally. The theoretical considerations addressed in this article inform practitioners, policymakers, and researchers about the essential components of nature-based solutions. The conceptual model can facilitate the identification of social and ecological interconnections within nature-based solutions and the range of stakeholders and disciplines involved.
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Affiliation(s)
- Konstantinos Tzoulas
- Department of Natural Sciences, Faculty of Science and Engineering, Manchester Metropolitan University, Chester Street, Manchester, M1 5GD UK
| | - Juanjo Galan
- Department of Architecture, Landscape Architecture, School of Arts, Design and Architecture, Aalto University, Otaniementie 14, 02150 Espoo, Finland
| | - Stephen Venn
- Ecosystems and Environment Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, P.O. Box 65, Viikinkaari 2a, 00014 Helsinki, Finland
| | - Matthew Dennis
- Department of Geography, School of Environment, Education and Development, The University of Manchester, Arthur Lewis G.037, Oxford Road, Manchester, M13 9PL UK
| | - Bas Pedroli
- Landscape Architecture and Spatial Planning Group, Wageningen University & Research, P.O. Box 47, 6700 AA Wageningen, The Netherlands
| | - Himansu Mishra
- Department of Landscape Architecture, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 56/3, 51006 Tartu, Estonia
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Dagmar Haase
- Humboldt University of Berlin, Alfred-Rühl-Haus, Rudower Chaussee 16, 12489 Berlin, Germany
| | - Stephan Pauleit
- Technical University of Munich, Emil-Ramann-Str. 6, 85354 Freising, Germany
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Jari Niemelä
- University of Helsinki, Yliopistonkatu 4, Helsinki, 00014 Finland
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Philip James
- School of Science, Engineering and Environment, University of Saflord, Peel Building, M5 4WT Salford, UK
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Du M, Du L, Wei N, Liu W, Bai X, Sun Z. Dual-gated mono-bilayer graphene junctions. Nanoscale Adv 2021; 3:399-406. [PMID: 36131752 PMCID: PMC9418045 DOI: 10.1039/d0na00547a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 09/30/2020] [Indexed: 05/29/2023]
Abstract
A lateral junction with an atomically sharp interface is extensively studied in fundamental research and plays a key role in the development of electronics, photonics and optoelectronics. Here, we demonstrate an electrically tunable lateral junction at atomically sharp interfaces between dual-gated mono- and bilayer graphene. The transport properties of the mono-bilayer graphene interface are systematically investigated with I ds-V ds curves and transfer curves, which are measured with bias voltage V ds applied in opposite directions across the asymmetric mono-bilayer interface. Nearly 30% difference between the output I ds-V ds curves of graphene channels measured at opposite V ds directions is observed. Furthermore, the measured transfer curves confirm that the conductance difference of graphene channels greatly depends on the doping level, which is determined by dual-gating. The V ds direction dependent conductance difference indicates the existence of a gate tunable junction in the mono-bilayer graphene channel, due to different band structures of monolayer graphene with zero bandgap and bilayer graphene with a bandgap opened by dual-gating. Simulation of the I ds-V ds curves based on a new numerical model validates the gate tunable junction at the mono-bilayer graphene interface from another point of view. The dual-gated mono-bilayer graphene junction and new protocol for I ds-V ds curve simulation pave a possible way for functional applications of graphene in next-generation electronics.
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Affiliation(s)
- Mingde Du
- Department of Electronics and Nanoengineering, Aalto University Espoo FI-02150 Finland
| | - Luojun Du
- Department of Electronics and Nanoengineering, Aalto University Espoo FI-02150 Finland
| | - Nan Wei
- Department of Applied Physics, School of Science, Aalto University Espoo FI-00076 Finland
| | - Wei Liu
- Department of Applied Physics, School of Science, Aalto University Espoo FI-00076 Finland
| | - Xueyin Bai
- Department of Electronics and Nanoengineering, Aalto University Espoo FI-02150 Finland
| | - Zhipei Sun
- Department of Electronics and Nanoengineering, Aalto University Espoo FI-02150 Finland
- QTF Centre of Excellence, Department of Applied Physics, Aalto University Espoo FI-00076 Finland
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