Extracting viscoelastic properties of soft polymers from dynamic nanoindentation using an improved model

Recently there is an increasing interest in using polydimethylsiloxane (PDMS)-based micropillars as bio-transducers for cellular forces measurements. Cells often produce cyclic motion, in which case the viscoelastic properties in the frequency domain are needed for force calculation. In this work, continuing on our prior time domain study, we measured the complex modulus of PDMS using a dynamic nanoindentation technique (DNT). An improved model for complex modulus extraction was developed for the flat punch indenter. The complex modulus of PDMS measured at small scale will allow for more accurate cellular force measurements in the frequency domain.