Fig. 3.

Typical force-time (bottom axis) and force-distance (top axis) curves associated with contact of a microtip surface with the flat surface of a silicon wafer (A, B). The inset illustrations correspond to the steps of retrieval (A) and delivery (B) for use of such a surface in a transfer printing mode. Plots of force required to remove a microtip surface (C) and a corresponding flat surface (D) from the silicon, as a function of retraction speed for three different preload cases, simulating the steps of retrieval (0.2 mN) and delivery (1.5, 3 mN) in a printing process. Modeling results for the microtip surface are indicated as a black line (C).