Indentation Testing of Axisymmetric Freestanding
Nanofilms
Using a MEMS Load Cell
Zayd Chad Leseman, Ph.D. Candidate
Department of Mechanical Engineering
University of Illinois Urbana-Champaign
Abstract
Accurate knowledge of the nanoscale mechanical properties
of thin films are important to the design and operation
of Integrated Circuits (IC’s), thin film optics, MEMS,
and nano-scale devices. Though bulk testing of materials,
and therefore bulk mechanical properties, are well established,
the nanoscale properties of like materials are not well
known. Mechanical characterization of thin films presents
numerous challenges, including: length scale effects, the
effect of native oxides, residual/intrinsic stresses, and
the mechanical complexities of nanoscale layering of thin
films.
Experiments for measuring the mechanical
properties of thin films fall into two key categories: films
tested on a substrate; and freestanding thin films. Typically,
thin films are deposited/grown on a substrate in their in-service
location. As such, testing of thin films located on a substrate
seems appropriate for determining the in-service mechanical
properties. However, measurements made on such films are
clearly influenced by the substrate. Thus, these experiments
yield mechanical properties of a composite structure not
of the thin film itself, especially for increasingly thinner
sub-micron films. In order to obtain directly the properties
of the thin films, it becomes necessary to test freestanding
thin films. This seminar will include details on the design,
fabrication, and implementation of a novel MEMS based load
cell to test axisymmetric freestanding thin films to determine
their nanoscale mechanical properties.
Biosketch
Zayd C. Leseman received his B.S. and M.S. degrees from
the Department of Mechanical and Industrial Engineering
at the University of Illinois Urbana-Champaign in 1997 and
2000, respectively. After obtaining his M.S., he started
his own company in which he designed, fabricated and patented
a MEMS based inkjet printhead. Currently, he is a Ph.D.
candidate at the University of Illinois Urbana-Champaign.
His research interests include: cell mechanics and mechanotransduction;
development of experiments for the determination of thin
film properties; microfluidics; and the design, fabrication,
and analysis of MEMS.
Thursday, February 23, 2006
2 PM, 337 Towne Bldg.
