Local thermomechanical characterization of phase transitions using band excitation atomic force acoustic microscopy with heated probe

Abstract

An approach for thermomechanical characterization of phase transitions in polymeric materials (polyethyleneterephthalate) by band excitation acoustic force microscopy is developed. This methodology allows the independent measurement of resonance frequency, Q factor, and oscillation amplitude of a tip-surface contact as a function of tip temperature, from which the thermal evolution of tip-surface spring constant and mechanical dissipation can be extracted. We demonstrate a heating protocol which keeps the contact area and contact force constant, thus allowing for reproducible measurements and quantitative extraction of material properties including temperature dependence of indentation-based elastic and loss moduli.

Relationship between Q-factor and sample damping for contact resonance atomic force microscope measurement of viscoelastic properties

“…Impressive quantitative and numerous qualitative results have been reported with various modifications of the basic AFM system. [2][3][4][5][6][7][8][9] One such modification, contact resonance force microscopy (CR-FM) [10][11][12] has become an increasingly important technique for characterizing mechanical properties of materials at submicrometer scales. CR-FM methods use the resonant modes of the AFM cantilever in order to evaluate near-surface mechanical properties.…”

Double-Layer Mediated Electromechanical Response of Amyloid Fibrils in Liquid Environment

“…The Young’s modulus of the material can be calculated from the measured resonance frequency as Jesse et al have already showed 66. Different contact resonances can be used to calculate contact stiffness as a function of frequency: $$f_{\text{italicres}}^i\cong true(1-b_i\frac{k_1}{k_2}true)f_{0\mathit{\text{BOUND}}}$$ where f res is the resonance frequency of the tip – surface contact, i is the order of the resonance, f 0BOUND is the resonance frequency of the tip in contact with infinitely stiff surface (this parameter depends only on the cantilever), k 1 is the spring constant of the cantilever, k 2 is the contact stiffness.…”

2-ω and 3-ω temperature measurement of a heated microcantilever

“…[3][4][5][6][7] Temperature calibration of heated AFM cantilevers is critically important for these and other applications. This article reports AFM cantilever temperature measurement and calibration under periodic heating.…”

“…[3][4][5]8 By exciting the cantilever over a range of periodic heating frequencies, it is possible to measure substrate thermomechanical properties at the nanometerscale. 7 When the cantilever is in a magnetic field, periodic current flowing through the cantilever can induce Lorentz forces on the cantilever. The corresponding cantilever mechanical oscillation allows high resolution imaging.…”