Noncontact Viscoelastic Imaging of Living Cells Using a Long-Needle Atomic Force Microscope with Dual-Frequency Modulation

Imaging the surface topography and elasticity of a living cell can provide new insights into the roles played by its volumetric and elastic properties in its functions and disease. Atomic force microscopy (AFM) would be a natural means to this end, but is designed for operation in air and does not function well in a liquid biological environment. The authors develop a technique for noncontact viscoelastic imaging of live cells using AFM with a long glass probe. This method opens the door to studying a wide range of interesting problems in the nanomechanics of soft matter and the mechanobiology of living cells and tissues.