Paper BM-TuP1
Electrowetting Using Probe of Atomic Force Microscope as Mobile Electrode

Tuesday, October 21, 2008, 6:30 pm, Room Hall D

The wetting behavior of liquid droplet on nanostructured surface can be dynamically tuned using electrowetting technique. A conductive AFM probe is used as a mobile electrode to replace the normally fixed electrode in conventional electrowetting setup. The forces involved in the electrowetting process are quantitatively measured from the deflection of AFM cantilever. The AFM tip geometry is precisely determined using SEM and calibration standard. The force between the AFM tip and the droplet is modeled and quantitatively compared with experimental results. By actuating the AFM probe vertically and laterally using the integrated piezo-driver, the droplet is actuated on the nanostructured surface in a fully controllable way due to the capillary force between the AFM tip and the droplet. The actuated droplet is used as a nano-vehicle to effectively transport and/or arrange other nano-objects on surface with capillary-induced manipulation, which opens a new way to integrate nanometer-sized building-blocks that were not movable with other methods.