A Scanning Microwave Microscope has been developed and applied within different contexts. It works through near-field microwave interaction between an emitting probe and a target sample. Its main application is the measurement, at extremely small scale, of electromagnetic features. Lumped and distributed circuit models allow getting quantitative data from measurements, although with limitations. Such models become even more complicated if considering different environments. This is fundamental for analyzing biological samples (in vitro or in vivo). During this work, both applications to biological samples and “in-liquid” analysis have been performed. Another potentiality of the microwave microscope is the spectroscopy at atomic/molecular level. One of the topics of this research, performed at University of Maryland, was the development of an instrument, working in cryogenic environment, for microwave spectroscopy of high-temperature superconductive materials. Atomic resolution would be useful in order to investigate non-linear phenomena at nanoscale. Another topic was the Electron Spin Resonance detection at microwave. The microscope has been modified in order to perform spectroscopy, with samples immersed in a magnetic field flux. Furthermore, the comprehensive description of the microscope resolution is essential. Then, investigations related to the “in-depth” penetration of the evanescent field are hereby presented. This capability is extremely interesting in order to get a “short-range” tomography of complex samples (e.g., cells). A “time-domain” conversion of the frequency microwave data has been applied. Finally, the Scanning Microwave Microscope has been employed in creating reproducible nanopatterns on graphene. This kind of pattening was observed experimentally, and then it was subject of theoretical and numerical investigation. This part of the research has been developed with Oak Ridge National Laboratories that provided the samples too.
Un Microscopio a Scansione di sonda a Microonde e’ stato sviluppato e applicato in vari contesti. Esso lavora attraverso l’interazione di campo vicino a microonde tra una sonda emittente e il campione in analisi. La sua applicazione principale e’ la misura delle proprieta’ elettromagnetiche su scale estremamente piccole. Modelli con circuiti a parametri concentrati e distribuiti consentono di ottenere dati quantitativi dalle misure. Tali modelli diventano piu’ complessi se si considerano ambienti diversi. Questo e’ fondamentale per analizzare campioni biologici (in vitro o in vivo). Durante questo lavoro sono state fatte sia applicazioni a campioni biologici sia analisi “in-liquido”. Un’ulteriore potenzialita’ del microscopio a microonde e’ la spettroscopia a livello atomico/molecolare. Uno degli argomenti di questa ricerca, affrontato presso la University of Maryland, e’ stato lo sviluppo di uno strumento, che lavorasse in ambiente criogenico, per la spettroscopia a microonde di materiali superconduttori ad alta temperature. La risoluzione atomica sarebbe stata utile per investigare i fenomeni non-lineari sulla nanoscala. Un’ulteriore tematica e’ stata la detection di Risonanze di Spin Elettronico a microonde. Il microscopio e’ stato modificato per effettuare spettroscopie, con campioni immerse in flussi di campo magnetico. Inoltre, un’esaustiva descrizione della risoluzione del microscopio e’ essenziale. Quindi, indagini riguardo la penetrazione “in-profondita’” del campo evanescente sono qui presentate. Questa capacita’ e’ estremamente interessante per ottenere una tomografia “a corto raggio” di campioni complessi (es.: cellule). E’ stata applicata una conversione nel dominio del tempo dei dati in frequenza a microonde. Infine, il Microscopio a Scansione di sonda a Microonde e’ stato impiegato per creare pattern riproducibili sul grafene. Questo tipo di pattern e’ stato osservato sperimentalmente, e quindi e’ stato oggetto di studi teorici e numerici. Questa parte della ricerca e’ stata sviluppata in collaborazione con gli Oak Ridge National Laboratories che hanno fornito anche i campioni.
Microwave microscopy and spectroscopy techniques with applications in nanotechnology and biology / Monti, Tamara. - (2014 Jan 15).
Microwave microscopy and spectroscopy techniques with applications in nanotechnology and biology
Monti, Tamara
2014-01-15
Abstract
A Scanning Microwave Microscope has been developed and applied within different contexts. It works through near-field microwave interaction between an emitting probe and a target sample. Its main application is the measurement, at extremely small scale, of electromagnetic features. Lumped and distributed circuit models allow getting quantitative data from measurements, although with limitations. Such models become even more complicated if considering different environments. This is fundamental for analyzing biological samples (in vitro or in vivo). During this work, both applications to biological samples and “in-liquid” analysis have been performed. Another potentiality of the microwave microscope is the spectroscopy at atomic/molecular level. One of the topics of this research, performed at University of Maryland, was the development of an instrument, working in cryogenic environment, for microwave spectroscopy of high-temperature superconductive materials. Atomic resolution would be useful in order to investigate non-linear phenomena at nanoscale. Another topic was the Electron Spin Resonance detection at microwave. The microscope has been modified in order to perform spectroscopy, with samples immersed in a magnetic field flux. Furthermore, the comprehensive description of the microscope resolution is essential. Then, investigations related to the “in-depth” penetration of the evanescent field are hereby presented. This capability is extremely interesting in order to get a “short-range” tomography of complex samples (e.g., cells). A “time-domain” conversion of the frequency microwave data has been applied. Finally, the Scanning Microwave Microscope has been employed in creating reproducible nanopatterns on graphene. This kind of pattening was observed experimentally, and then it was subject of theoretical and numerical investigation. This part of the research has been developed with Oak Ridge National Laboratories that provided the samples too.File | Dimensione | Formato | |
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