Before revision: Materials with tunable mechanical properties are ubiquitous in biology and engineering, such as muscle , the cytoskeleton, soft robotic actuators, and magnetorheological fluids. Their functionality arises through an external signal that modulates intrinsic mechanical properties, like neural spikes in muscle. However, current rheological methods assume approximately invariant mechanical properties during measurement, and thus cannot be used for characterizing the rheology of tunable materials.
After revision: This paper proposes a hypothesis for the tunable rheology of skeletal muscle and thus cannot be used for characterizing the rheology of tunable materials.