Dynamic nanoindentation techniques are required to measure the viscoelastic properties of small volumes of material and localized regions of sample surfaces. Viscoelastic materials exhibit a creep response during standard quasi-static nanoindentation measurements, making it unreliable to utilize quasi-static techniques and models to calculate elastic properties of these materials. Dynamic nanoindentation provides the ability to characterize the combined elastic and viscous components of the material deformation response for quantitative characterization of amorphous polymers, semicrystalline polymers, biopolymers, and biological tissues.
Bruker’s nanoDMA III is a powerful dynamic nanoindentation technique developed specifically for quantitative viscoelastic property characterization. During a dynamic nanoindentation test, an oscillatory force is us superimposed over the quasi-static loading profile of the measurement. By continuously monitoring the resulting displacement amplitude and phase lag of the material’s response, quantitative measurement of storage modulus, loss modulus, and tan-delta can be achieved as a function of testing frequency. Combined with one of Bruker’s temperature control stages, time-temperature-transformation studies can be performed at the nanoscale.