The mechanical properties of tissues and cells have proven to be of great importance in biology and medicine, spawning major research efforts and commercial outcomes. The interplay between mechanical and biochemical cues and the mechanical properties of subcellular and cellular constituents has come to be appreciated as key to understanding many fundamental aspects of biology as well as the genesis and progression of disease. At the same time, at the other extreme, the mechanical properties of whole organs and their constituents have been shown to be effective markers of disease on the scale of the human body, as probed by ultrasound elastography and magnetic resonance elastography, both of which, after 20-year gestations, have reached commercial markets.