Figure 7
Microdroplet transfer.
(a) Transfer of a water droplet (30 μL) from superhydrophobic PTFE film to a 200 nm-grating film at original (ɛ = 0%) state and then to a third surface with a much lower CA (Si wafer). (b) Failure to transfer a water droplet (30 μL) to the deformed (ɛ = 200%) 200 nm-grating. (c) When the volume of water droplet is reduced to 10 μL, a successful transfer of the microdroplet between the PTFE film and the deformed (ɛ = 200%) 200 nm-grating and then to a Si wafer is shown. Stage I: A microdroplet is placed on a PTFE film. Stage II: 200 nm-grating film is brought into contact with the water droplet and lifted up. Stage III: For (a,c), the microdroplet adheres to the 200 nm-grating, whereas the grating failed to pick up the water droplet for (b). Stage IV: For (a,c), the water droplet on the 200 nm-grating can be detached to a third surface (Si wafer).
