AbstractMagnetically responsive soft materials that change elastic modulus upon application of a magnetic field have many applications but have only recently been applied to biological studies. The ability to make magnetoelastic materials with shear moduli between 100 and 10,000 Pa, which span the range of most soft tissues, enables many new methods to study the response of cells to a changing mechanical environment. In this chapter, we summarize some properties of magnetoelastic soft elastomers and hydrogels, with an emphasis on hydrogels comprised of fibrous polymers that mimic the extracellular matrix forming most soft tissues. An example of the utility of these materials is the demonstration that cells respond within seconds to a nearly instantaneous change in environmental stiffness. This response involves intracellular calcium fluxes, identifying this mechanism as perhaps the initial signal that cells use for mechanobiological control.
