SUBJECT: Ph.D. Dissertation Defense
BY: Brent Nelson
TIME: Wednesday, March 28, 2007, 11:00 a.m.
PLACE: Love Building, 311
TITLE: Nanoscale Thermal Processing Using a Heated Atomic Force Microscope Tip
COMMITTEE: Dr. William P. King, Chair (ME)
Dr. Yogendra Joshi (ME)
Dr. F. Levent Degertekin (ME)
Dr. Alexei Marchenkov (Phys)
Dr. William Koros (ChBE)


The proposed thesis aims to advance the current state of use of silicon atomic force microscope (AFM) cantilevers with integrated heaters. To this end, the research consists of two primary thrusts - demonstrating new applications for the cantilevers, and advancing the current state of understanding of their thermal and mechanical behavior to enable further applications. Among new applications, two will be described. In the first application, the cantilevers are used for nanoscale material deposition, using the nanoscale tip as a delivery vehicle and using heat to modulate the delivery. In the second application, the cantilever performs thermal analysis with nanoscale spatial resolution, enabling thermal characterization of near surface and composite interphase regions that cannot be measured with bulk analysis techniques. The second thrust of the research seeks to address fundamental questions concerning the precision use of heated cantilevers. Efforts to this end include characterizing the electrical and thermal behavior of the cantilevers, and optimizing calibration methodology. The mechanical behavior of the cantilevers at elevated temperature is also studied, and a technique is developed for calibrating the cantilever spring constant while operating at elevated temperature. Finally, the heat flow in the cantilever tip is characterized, and relevant dimensionless numbers that govern the relative importance of the various components of the thermal environment are identified. The dimensionless numbers then permit exploration of the sensitivity of the tip-substrate interface temperature to the environmental conditions.