Frontiers in Nanotechnology最新文献

{"title":"Thermofluidic assembly of colloidal crystals","authors":"D. Quinn, F. Cichos","doi":"10.3389/fnano.2023.1135408","DOIUrl":"https://doi.org/10.3389/fnano.2023.1135408","url":null,"abstract":"Colloidal crystals are interesting as functional structures due to their emergent photonic properties like photonic stop bands and bandgaps that can be used to redirect light. They are commonly formed by a drying process that is assisted by capillary forces at the drying fronts. In this manuscript, we demonstrate the optically induced dynamic thermofluidic assembly of 2D and 3D colloidal crystals. We quantify in experiment and simulation the structure formation and identify thermo-osmosis and temperature induced depletion interactions as the key contributors to the colloidal crystal formation. The non-equilibrium nature of the assembly of colloidal crystals and its dynamic control by laser-induced local heating promise new possibilities for a versatile formation of photonic structures inaccessible by equilibrium processes.","PeriodicalId":34432,"journal":{"name":"Frontiers in Nanotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46751099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature-controlled optical switch metasurface with large local field enhancement based on FW-BIC","authors":"Xiuyu Wang, Xiaoman Wang, Q. Ren, Haocheng Cai, J. Xin, Yuxin Lang, Xiaofei Xiao, Z. Lan, J. You, W. E. Sha","doi":"10.3389/fnano.2023.1112100","DOIUrl":"https://doi.org/10.3389/fnano.2023.1112100","url":null,"abstract":"Introduction: Many researchers have explored the bound states in the continuum (BICs) as a particular bound wave state which can be used to achieve a very high Q-factor. High-Q factor devices, typically based on the bound states in the continuum (BICs), are well used in the fields of hypersensitive biochemical sensors, non-linear effects enhancement, plasmon lasers, and hi-performance filtering. However, symmetrical-protected BIC is difficult to achieve experimentally high-Q factor because it strongly depends on the geometry and can be destroyed by any slight disturbance in the potential well. Methods: Therefore, we proposed a parameter-adjusted Friedrich-Wintergen BIC based on the analysis model of time-coupled model theory, where the target system parameters can be tuned to achieve high-Q excitation. Results: Moreover, considering the tunability and flexibility of the components in various practical applications, we integrate active materials into metasurface arrays with the help of external stimuli to achieve modulation of high-Q resonances. Our results demonstrate that an optical resonator based on FW-BIC can modulate the BIC state by changing the intermediate gap. Discussion: The BIC state and the high-Q factor Fano resonance can be dynamically tuned by adding temperature-sensitive VO 2 material.","PeriodicalId":34432,"journal":{"name":"Frontiers in Nanotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48799570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphology control of volatile resistive switching in La0.67Sr0.33MnO3 thin films on LaAlO3 (001)","authors":"A. Jaman, A. Goossens, J. J. L. van Rijn, L. van der Zee, T. Banerjee","doi":"10.3389/fnano.2023.1121492","DOIUrl":"https://doi.org/10.3389/fnano.2023.1121492","url":null,"abstract":"The development of in-memory computing hardware components based on different types of resistive materials is an active research area. These materials usually exhibit analog memory states originating from a wide range of physical mechanisms and offer rich prospects for their integration in artificial neural networks. The resistive states are classified as either non-volatile or volatile, and switching occurs when the material properties are triggered by an external stimulus such as temperature, current, voltage, or electric field. The non-volatile resistance state change is typically achieved by the switching layer’s local redox reaction that involves both electronic and ionic movement. In contrast, a volatile change in the resistance state arises due to the transition of the switching layer from an insulator to a metal. Here, we demonstrate volatile resistive switching in twinned LaAlO3 onto which strained thin films of La0.67Sr0.33MnO3 (LSMO) are deposited. An electric current induces phase transition that triggers resistive switching, close to the competing phase transition temperature in LSMO, enabled by the strong correlation between the electronic and magnetic ground states, intrinsic to such materials. This phase transition, characterized by an abrupt resistance change, is typical of a metallic to insulating behavior, due to Joule heating, and manifested as a sharp increase in the voltage with accompanying hysteresis. Our results show that such Joule heating-induced hysteretic resistive switching exhibits different profiles that depend on the substrate texture along the current path, providing an interesting direction toward new multifunctional in-memory computing devices.","PeriodicalId":34432,"journal":{"name":"Frontiers in Nanotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43108590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Energy-efficient and noise-tolerant neuromorphic computing based on memristors and domino logic","authors":"Hagar Hendy, Cory E. Merkel","doi":"10.3389/fnano.2023.1128667","DOIUrl":"https://doi.org/10.3389/fnano.2023.1128667","url":null,"abstract":"The growing scale and complexity of artificial intelligence (AI) models has prompted several new research efforts in the area of neuromorphic computing. A key aim of neuromorphic computing is to enable advanced AI algorithms to run on energy-constrained hardware. In this work, we propose a novel energy-efficient neuromorphic architecture based on memristors and domino logic. The design uses the delay of memristor RC circuits to represent synaptic computations and a simple binary neuron activation function. Synchronization schemes are proposed for communicating information between neural network layers, and a simple linear power model is developed to estimate the design’s energy efficiency for a particular network size. Results indicate that the proposed architecture can achieve 1.26 fJ per classification per synapse and achieves high accuracy on image classification even in the presence of large noise.","PeriodicalId":34432,"journal":{"name":"Frontiers in Nanotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43388241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Large-scale nano-biosensing technologies","authors":"I. Tzouvadaki, T. Prodromakis","doi":"10.3389/fnano.2023.1127363","DOIUrl":"https://doi.org/10.3389/fnano.2023.1127363","url":null,"abstract":"Nanoscale technologies have brought significant advancements to modern diagnostics, enabling unprecedented bio-chemical sensitivities that are key to disease monitoring. At the same time, miniaturized biosensors and their integration across large areas enabled tessellating these into high-density biosensing panels, a key capability for the development of high throughput monitoring: multiple patients as well as multiple analytes per patient. This review provides a critical overview of various nanoscale biosensing technologies and their ability to unlock high testing throughput without compromising detection resilience. We report on the challenges and opportunities each technology presents along this direction and present a detailed analysis on the prospects of both commercially available and emerging biosensing technologies.","PeriodicalId":34432,"journal":{"name":"Frontiers in Nanotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45294184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Choose your tools carefully: a comparative evaluation of deterministic vs. stochastic and binary vs. analog neuron models for implementing emerging computing paradigms","authors":"Md Golam Morshed, S. Ganguly, Avik W. Ghosh","doi":"10.3389/fnano.2023.1146852","DOIUrl":"https://doi.org/10.3389/fnano.2023.1146852","url":null,"abstract":"Neuromorphic computing, commonly understood as a computing approach built upon neurons, synapses, and their dynamics, as opposed to Boolean gates, is gaining large mindshare due to its direct application in solving current and future computing technological problems, such as smart sensing, smart devices, self-hosted and self-contained devices, artificial intelligence (AI) applications, etc. In a largely software-defined implementation of neuromorphic computing, it is possible to throw enormous computational power or optimize models and networks depending on the specific nature of the computational tasks. However, a hardware-based approach needs the identification of well-suited neuronal and synaptic models to obtain high functional and energy efficiency, which is a prime concern in size, weight, and power (SWaP) constrained environments. In this work, we perform a study on the characteristics of hardware neuron models (namely, inference errors, generalizability and robustness, practical implementability, and memory capacity) that have been proposed and demonstrated using a plethora of emerging nano-materials technology-based physical devices, to quantify the performance of such neurons on certain classes of problems that are of great importance in real-time signal processing like tasks in the context of reservoir computing. We find that the answer on which neuron to use for what applications depends on the particulars of the application requirements and constraints themselves, i.e., we need not only a hammer but all sorts of tools in our tool chest for high efficiency and quality neuromorphic computing.","PeriodicalId":34432,"journal":{"name":"Frontiers in Nanotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42126762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polarization multiplexing multichannel high-Q terahertz sensing system","authors":"Xiuyu Wang, Xiaoman Wang, Q. Ren, Haocheng Cai, J. Xin, Yuxin Lang, Xiaofei Xiao, Z. Lan, J. You, W. E. Sha","doi":"10.3389/fnano.2023.1112346","DOIUrl":"https://doi.org/10.3389/fnano.2023.1112346","url":null,"abstract":"Terahertz functional devices with high-Q factor play an important role in spectral sensing, security imaging, and wireless communication. The reported terahertz devices based on the electromagnetic induction transparency (EIT) effect cannot meet the needs of high-Q in practical applications due to the low-Q factor. Therefore, to increase the Q-factor of resonance, researchers introduced the concept of bound state in the continuum (BIC). In the quasi-BIC state, the metasurface can be excited by the incident wave and provide resonance with a high-Q factor because the condition that the resonant state of the BIC state is orthogonal is not satisfied. The split ring resonator (SRR) is one of the most representative artificial microstructures in the metasurface field, and it shows great potential in BIC. In this paper, based on the classical single-SRR array structure, we combine the large and small SRR and change the resonance mode of the inner and outer SRR by changing the outer radius of the inner SRR. The metasurface based on parameter-tuned BIC verified that the continuous modulation of parameters in a system could make a pair of resonant states strongly coupled, and the coherent cancellation of the resonant states will cause the linewidth of one of the resonant states to disappear, thus forming BIC. Compared with the single-SRR array metasurface based on symmetry-protected BIC, the dual-SRR array metasurface designed in this paper has multiple accidental BICs and realizes multichannel multiplexing of X-polarization and Y-polarization. It provides a brilliant platform for high-sensitivity optical sensor array, low threshold laser and efficient optical harmonic generation.","PeriodicalId":34432,"journal":{"name":"Frontiers in Nanotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46752313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Versatile and active THz wave polarization modulators using metamaterial/graphene resonators","authors":"A. Zaman, Yuezhen Lu, N. Almond, Oliver J. Burton, J. Alexander-Webber, S. Hofmann, T. Mitchell, J. Griffiths, H. Beere, D. Ritchie, R. Degl’Innocenti","doi":"10.3389/fnano.2023.1057422","DOIUrl":"https://doi.org/10.3389/fnano.2023.1057422","url":null,"abstract":"Active modification of the polarization state is a key feature for the next-generation of wireless communications, sensing, and imaging in the THz band. The polarization modulation performance of an integrated metamaterial/graphene device is investigated via a modified THz time domain spectroscopic system. Graphene’s Fermi level is modified through electrostatic gating, thus modifying the device’s overall optical response. Active tuning of ellipticity by > 0.3 is reported at the resonant frequency of 0.80 THz. The optical activity of transmitted THz radiations is continuously modified by > 21 . 5 o at 0.71 THz. By carefully selecting the transmitted frequency with the relative angle between the incoming linear polarization and the device’s symmetry axis, active circular dichroism and optical activity are almost independently exploited. Finally, this all-electronically tuneable versatile polarization device can be used in all applications requiring an ultrafast modulation such as polarization spectroscopy, imaging, and THz wireless generation.","PeriodicalId":34432,"journal":{"name":"Frontiers in Nanotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46680271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Editorial: Advanced characterization methods for HfO2/ZrO2-based ferroelectrics","authors":"P. Lomenzo, U. Celano, T. Kämpfe, S. Mcmitchell","doi":"10.3389/fnano.2023.1114267","DOIUrl":"https://doi.org/10.3389/fnano.2023.1114267","url":null,"abstract":"Ferroelectric HfO2 and ZrO2-based materials are unconventional ferroelectrics compared to historically dominant perovskite-based ferroelectrics. These differences from conventional perovskite ferroelectrics are distinctly seen in HfO2-ZrO2’s fluorite-based structure that exhibits a rich polymorphism of competing crystal phases, enhanced ferroelectric behavior when scaling film thicknesses down to 10 nm and below, and a one order of magnitude lower relative permittivity and higher coercive field. Both the complex interplay of the fluorite crystal phases, as well as the intrinsic material and/or ferroelectric properties associated with them, have made ferroelectric HfO2-ZrO2-based ferroelectrics simultaneously challenging and interesting to characterize. Due in strong part to the nanoscale thicknesses of these fluorite-based ferroelectric films, the device behavior is an inseparable combination of the ferroelectric film properties (i.e., structure, crystalline orientation, grain size) and the material stack structure that encapsulates it into a two or three terminal device (i.e., interfaces, dielectric layers, electrode materials). Each article comprising this Research Topic on advanced characterization methods for HfO2/ZrO2-based ferroelectric illustrates different ways in which the intrinsic material properties or the ferroelectric film’s interaction with the device stack can be characterized to gain physical insight into this unconventional ferroelectric material system. Surface energy effects and grain size are often attributed to the predominant stabilization of either the non-polar tetragonal, monoclinic, or the polar orthorhombic phases in polycrystalline HfO2–ZrO2 films. It is generally observed that the polar orthorhombic phase is stabilized somewhere between the non-polar tetragonal and monoclinic phase boundaries, and that these non-polar phases are very sensitive to grain size in both HfO2 and ZrO2. Since the preferred crystal phase-dependence on grain size can be sensitive to stoichiometry (for instance, in Hf1xZrxO2 or Si-doped HfO2), it can be anticipated that there may be a complex interplay between grain-size engineering and ferroelectric film composition. In “Effect of Al2O3 interlayers on the microstructure and electrical response of ferroelectric doped HfO2 thin films” by Lederer et al., the grain-size and composition dependence of ferroelectric Hf1-xZrxO2 and Si-doped HfO2 is investigated in detail in which 1, 2, and 3 Al2O3 interlayers are used to control grain size while adjusting the stoichiometry of the fluorite-structured ferroelectric films. Using a combination of structural techniques, such as grazing-incidence X-ray diffraction and Kikuchi diffraction, as OPEN ACCESS","PeriodicalId":34432,"journal":{"name":"Frontiers in Nanotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42710064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nucleation control of quantum dot synthesis in a microfluidic continuous flow reactor","authors":"Eun Byoel Kim, Kyle Tomczak, H. B. Chandrasiri, Marcell Pálmai, A. Ghaznavi, D. Gritsenko, J. Xu, P. Snee","doi":"10.3389/fnano.2022.1096267","DOIUrl":"https://doi.org/10.3389/fnano.2022.1096267","url":null,"abstract":"The use of microfluidics in chemical synthesis is topical due to the potential to improve reproducibility and the ability promptly interrogate a wide range of reaction parameters, the latter of which is necessary for the training of artificial intelligence (AI) algorithms. Applying microfluidic techniques to semiconductor nanocrystals, or quantum dots (QDs), is challenging due to the need for a high-temperature nucleation event followed by particle growth at lower temperatures. Such a high-temperature gradient can be realized using complex, segmented microfluidic reactor designs, which represents an engineering approach. Here, an alternative chemical approach is demonstrated using the cluster seed method of nanoparticle synthesis in a simple microfluidic reactor system. This enables quantum dot nucleation at lower temperatures due to the presence of molecular organometallic compounds (NMe4)4[Cd10Se4(SPh)16] and (NMe4)4[Zn10Se4(SPh)16]. This integration of cluster seeding with microfluidics affords a new mechanism to tailor the reaction conditions for optimizing yields and tuning product properties. Graphical Abstract","PeriodicalId":34432,"journal":{"name":"Frontiers in Nanotechnology","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48399014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}