Fig. 2. Adhesion of the DIAs via structural deformation in dry and wet conditions.

(A) Profiles of normal adhesion for different adhesive samples against silicon wafers in dry and underwater conditions. A preload of 2 N/cm² is applied for each measurement. (B) Measurements of normal adhesion in dry and underwater conditions with varied material properties of the DIA tip. wt %, weight %. (C) Measurements of normal adhesion in dry and underwater conditions for s-DIAs of different diameters. (D) (i) FEM simulation analysis of stress distribution during the application of a 2 N/cm² preload. (ii) Volume expansion of the inner chamber during detachment to yield the suction effect. (E) Comparison of stress distribution via FEM simulation for the bottom surface of (i) DIA and (ii) MCP. (F) Predicted (green) and experimental results of normal adhesive strength in dry and underwater conditions corresponding to preload for different adhesive samples.