Table 1.

Percentage of Cells that Were Considered Valid Fits for Both of the Models

Indentation Rate $\left(\frac{\mu \mathrm{m}}{\mathrm{s}}\right)$	Brush Model (Percent Retained) (Nkept/Ntested)	Elastic Layer Model (Percent Retained) (Nkept/Ntested)
1	36% (46/127)	54% (68/127)
4	57% (66/115)	85% (98/115)
10	63% (67/105)	89% (93/105)

Curve fits were considered valid if the coefficient of variation was less than 10% for the three fitted parameters.