Table 1 AFM tip geometry parameters obtained from an elastic analysis of PDMS indentation data

From: Atomic force microscope protocols for characterising the elastoviscoplastic biomechanical properties of corneocytes

\({h}_{c}\) (nm)

10

20

40

60

80

160

m

1.184 ± 0.004

1.240 ± 0.004

1.311 ± 0.002

1.380 ± 0.002

1.45 ± 0.002

1.663 ± 0.005

n

5.41 ± 0.10

4.62 ± 0.08

3.21 ± 0.03

2.63 ± 0.01

2.22 ± 0.01

1.51 ± 0.01

\(c\) (µm1−n)

(7.80 ± 3.11) × 10−8

(5.90 ± 1.31) × 10−6

(1.85 ± 0.21) × 10−4

(1.65 ± 0.09) × 10−3

(8.30 ± 0.02) × 10−3

0.16 ± 0.01

  1. The load index, \(m\), of the power law was calculated at different contact depths, \({h}_{c}\), based on a polynomial fit of PDMS loading curves. The plane strain elastic modulus, \({E}^{* }\), of the PDMS specimen required to derive the tip geometry was independently calculated from micromanipulation experiments based on the indentation of 3 different regions. The derived parameters \(c\) and \(n\) define the local geometry of the AFM tip at different selected contact depths. Mean ± 1 SD.
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