Figure 2

Surface chemical modification of open capillaries.

(a) Schematic illustrations of surface physical/chemical modifications of the VI leg. Cut legs were physically modified by gold sputtering. The gold-sputtered legs were chemically modified using by hydrophilic and hydrophobic compounds. (b) Top view of measurement area of wettability analysis. (c) Projection view of the small volume droplet by a 1,000 fps high-speed camera in wettability analysis. (d) Water contact angles of the chemical-modified flat mica substrates (θ_f, yellow), the HLP area (θ_h, red) the PLP area (θ_p, blue) and the outside of open capillaries (θ_o, black) of the 4^th podite plotted against the molar ratio of the hydrophobic thiol compound (r). Solid arrows indicate the samples shown in water transport analysis (Fig. 3).