Date of Award

2003

Degree Name

M.S. in Mechanical Engineering

Department

Department of Mechanical and Aerospace Engineering

Abstract

Today, nanotechnology has become central to our research efforts in order to come up with smaller and smaller devices, which are more versatile than their older and bigger predecessors. MEMS devices, biosensors, nanocomposites are some of the examples of these devices. To realize the goal of fabricating these devices newer materials and novel techniques to manufacture these materials at spatial scales, heretofore unseen, are required. Also, we need to know the mechanical properties of these materials at nanoscales and we have to strive for environmentally benign ways of achieving these production goals. Silica is a very important material in this regard. Recently, a new biomimetically inspired path to silica production has been demonstrated. This processing technique was inspired from biological organisms, such as marine diatoms, which produce silica at ambient conditions and almost neutral ph with beautiful control over location and structure. Recently, several researchers have demonstrated that positional control of silica formed could be achieved by application of an electric field to iiilocate charged enzymes responsible for the bio catalytic condensation of silica from solution. Secondly, chemical and physical controls of silica structural morphology were achievable. Research now documents the effect of these “controls” on the mechanical and structural properties of the silica formed. Atomic Force Microscopy (AFM) and Ultrasonic Force Microscopy (UFM) is used for the first time to provide both substantially improved resolution of the morphology and relative measurement of the modulus of elasticity of the structures. In particular, these measurements reveal the positive impact of a shear flow field present during the silica formation on both the “ordering” of the structure and the mechanical properties.

Keywords

Silica Microstructure, Atomic force microscopy, Ultrasonic imaging

Rights Statement

Copyright 2003, author

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