Mechanotransduction describes the molecular mechanisms by which cells respond to changes in their physical environment by translating mechanical stimuli into biochemical signals. These mechanical changes can be either forces exerted on the cell from the environment or intracellular forces arising from cell responses to stiffness/topography modifications. The mechanical properties of cells are mainly determined by the cytoskeleton and nucleus, and are essential in major cell functions. Studies suggest that cancer cells acquire specific mechanical properties allowing them to deform more strongly than healthy cells.

We have reported on the viscosity of eukaryotic living cells using an active microrheological technique, where magnetic wires, embedded into cells, are being actuated remotely. It was shown that this technology is able to measure the viscosity of fluids with high accuracy, for samples down to 1 µL volume. Interestingly, the cytoplasm viscosity measured displays anomalous transient responses characterized by intermittent phases of low and high viscosity. An analysis based on mathematical finance statistical tools was performed, revealing specific intracellular relaxation times not previously disclosed. The current approach could be exploited to reveal hidden features from biological complex systems, or determine new biomarkers of cellular metabolism.