We review nano-palpation atomic force microscopy, which offers quantitative mechanical property mapping especially for soft materials. The method measures force-deformation curves on the surfaces of soft materials. The emphasis is placed on how both Hertzian and Derjaguin-Muller-Toporov contact mechanics fail to reproduce the experimental curves and, alternatively, how the Johnson-Kendall-Roberts model does. We also describe the force-volume technique for obtaining a two-dimensional map of mechanical properties, such as the elastic modulus and adhesive energy, based on the above-mentioned analysis. Finally, we conclude with several counterpart measurements, which describe the viscoelastic nature of soft materials, and give examples, including vulcanized isoprene rubber and the current status of ISO standardization.

Controlling the cellular microenvironment can be used to direct the cellular organization, thereby improving the function of synthetic tissues in biosensing, biorobotics, and regenerative medicine. In this study, we were inspired by the microstructure and biological properties of the extracellular matrix to develop freestanding ultrathin polymeric films (referred as "nanomembranes") that were flexible, cell adhesive, and had a morphologically tailorable surface. The resulting nanomembranes were exploited as flexible substrates on which cell-adhesive micropatterns were generated to align C2C12 skeletal myoblasts and embedded fibril carbon nanotubes enhanced the cellular elongation and differentiation. Functional nanomembranes with tunable morphology and mechanical properties hold great promise in studying cell-substrate interactions and in fabricating biomimetic constructs toward flexible biodevices.

The surface morphology and nanomechanical properties of poly(styrene-b-ethylene-cobutylene-b-styrene) (SEBS) having different compositions were investigated using nanomechanical mapping measurements based on atomic force microscopy. We obtained the deformation image, true surface morphology, high-resolution Young's modulus map, and map of deviated work simultaneously in a force mapping. Such maps were successfully used to identify and characterize the composition and better understand the relationship between microstructure and properties of SEBS samples. It is found that the obtained Young's modulus and deformation values, both for polystyrene (PS) or poly(ethylene-co-butylene) (PEB) blocks, strongly depend on the microstructure that is dominated by the composition. As the PS composition increase, the modulus of PS blocks increases from 19.2 ( 2.5 MPa for SEBS (10/80/10) to 823.0 ( 168.1 MPa for SEBS (33.5/33/33.5), while PEB's increases from 8.7 ( 2.1 MPa for SEBS (10/80/10) to 97.6 ( 17.8 MPa for SEBS (33.5/33/33.5). The calculated map of deviated work from elastic model will be a convenient technique to visualize the distribution of viscoelasticity. Furthermore, the reconstructed true height image reveals the true topographic feature free from sample deformation.