TABLE II. PARAMETERS OF CONTACT REGIME.
| Parameter | Contact level | Contact time | Tip moving speed |
|---|---|---|---|
| Contact level (nm) | 1, 3, 5, 10 | 5 | 5 |
| Contact time (ms) | No delay | 500, 1000 | 1000 |
| Tip moving speed (nm/s) | 100 | 100 | 100, 200, 400 |
| Tip moving distance (nm) | 200 | 200 | 200 |
Each column is an experimental condition during optimization.