Thermomechanical sensitivity of microcantilever in the mid-infrared spectral region

Kwon, Beomjin

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https://hdl.handle.net/2142/14659 Copy

Description

Title

Thermomechanical sensitivity of microcantilever in the mid-infrared spectral region

Author(s)

Kwon, Beomjin

Issue Date

2010-01-06T16:20:42Z

Director of Research (if dissertation) or Advisor (if thesis)

King, William P.

Doctoral Committee Chair(s)

King, William P.

Department of Study

Mechanical Sci & Engineering

Discipline

Mechanical Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Bimaterial
• Microcantilevers
• infrared
• thermomechanical
• photothermal
• FT-IR microscopy
• monochromator
• modeling

Abstract

This paper reports the thermomechanical sensitivity of bimaterial cantilevers over a mid-infrared (IR) spectral range (5-10 µm) that is critical both for chemical analysis via vibrational spectroscopy and for direct thermal detection in the 300-700 K range. Mechanical bending sensitivity and noise were measured and modeled for six commercially available microcantilevers, which consist of either an aluminum film on a silicon cantilever or a gold film on a silicon nitride cantilever. The spectral sensitivity of each cantilever was determined by recording cantilever deflection when illuminated with IR light from a monochromator. Rigorous modeling and systematic characterization of the optical system allowed for a quantitative estimate of IR energy incident upon the cantilever. Separately, spectral absorptance of the cantilever was measured using Fourier transform infrared (FT-IR) microscopy, which was compared with analytical models of radiation onto the cantilever and heat flow within the cantilever. The predictions of microcantilever thermomechanical bending sensitivity and noise agree well with measurements, resulting in a ranking of these cantilevers for their potential use in IR measurements.

Graduation Semester

2009-12

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http://hdl.handle.net/2142/14659

Copyright and License Information

Copyright 2009 Beomjin Kwon

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