Academic Journal
A communications system perspective for dynamic mode atomic force microscopy, with applications to high-density storage and nanoimaging
| العنوان: | A communications system perspective for dynamic mode atomic force microscopy, with applications to high-density storage and nanoimaging |
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| المؤلفون: | Kumar, Naveen |
| المساهمون: | Aditya Ramamoorthy, Murti V. Salapaka, Electrical and Computer Engineering |
| المصدر: | archive/lib.dr.iastate.edu/etd/11792/Kumar_iastate_0097E_11591.pdf|||Fri Jan 14 18:58:10 UTC 2022 |
| سنة النشر: | 2010 |
| المجموعة: | Digital Repository @ Iowa State University |
| مصطلحات موضوعية: | Electrical and Computer Engineering, Atomic Force Microscope, High-density data storage, MLSD, Nano-imaging, Viterbi algorithm |
| الوصف: | In recent times, the atomic force microscope (AFM) has been used in various fields like biology, chemistry, physics and medicine for obtaining atomic level images. The AFM is a high-resolution microscope which can provide the resolution on the order of fractions of a nanometer. It has applications in the field of material characterization, probe based data storage, nano-imaging etc. The prevalent mode of using the AFM is the static mode where the cantilever is in continuous contact with the sample. This is harsh on the probe and the sample. The problem of probe and sample wear can be partly addressed by using the dynamic mode operation with the high quality factor cantilevers. In the dynamic mode operation, the cantilever is forced sinusoidally using a dither piezo. The oscillating cantilever gently taps the sample which reduces the probe-sample wear. In this dissertation, we demonstrate that viewing the dynamic mode operation from a communication systems perspective can yield huge gains in nano-interrogation speed and fidelity. In the first part of the dissertation, we have considered a data storage system that operates by encoding information as topographic profiles on a polymer medium. A cantilever probe with a sharp tip (few nm radius) is used to create and sense the presence of topographic profiles, resulting in a density of few Tb per square inch. The usage of the static mode is harsh on the probe and the media. In this work, the high quality factor dynamic mode operation, which alleviates the probe-media wear, is analyzed. The read operation is modeled as a communication channel which incorporates system memory due to inter-symbol interference and the cantilever state. We demonstrate an appropriate level of abstraction of this complex nanoscale system that obviates the need for an involved physical model. Next, a solution to the maximum likelihood sequence detection problem based on the Viterbi algorithm is devised. Experimental and simulation results demonstrate that the performance of this detector is ... |
| نوع الوثيقة: | article in journal/newspaper doctoral or postdoctoral thesis |
| وصف الملف: | application/pdf |
| اللغة: | English |
| Relation: | archive/lib.dr.iastate.edu/etd/11792/; 2759; 2807957; etd/11792; https://dr.lib.iastate.edu/handle/20.500.12876/25998 |
| DOI: | 10.31274/etd-180810-481 |
| الاتاحة: | https://dr.lib.iastate.edu/handle/20.500.12876/25998 https://hdl.handle.net/20.500.12876/25998 https://doi.org/10.31274/etd-180810-481 |
| رقم الانضمام: | edsbas.FB8A3BCE |
| قاعدة البيانات: | BASE |
| DOI: | 10.31274/etd-180810-481 |
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