Table 1.

Material properties of the cellular components.

	Cytoplasm	Membrane	Microtubules
Elastic modulus (Pa)	10032	100032	1.2 × 109  31
Poisson’s ratio	0.3733	0.332	0.331
τ (s)	300a	20	0

^aAt present, there is no clear data on the viscosity $\eta$ of cytoplasm. Based on experimental data¹², we take $\tau =\eta /E$ as 300 s.