Dynamic measurement of a single polymer chain by atomic force microscopy

We performed the measurement of the dynamic viscoelasticity of a single polymer chain by the self-produced piezo-control and data acquisition system externally built on the commercial atomic force microscope (AFM). The sinusoidal movement with the small amplitude was applied to a single polymer chain at the several points in the middle of elongation, and the response of the molecule was evaluated. As the result of the experiment, some dissipative behavior was observed in the low-elongation region of the polymer chain, which could have never been observed in the simple elongation experiment. This behavior may be due to the friction between the monomers constituting a polymer chain.