Fabrication of micro/nanostructures as SERS substrates with the feed-back controlled normal force

Different from the conventional scratching method, the normal force is feed-back controlled to mechanically machine the micro grooves in the present study. During the process, the normal force is controlled to a constant value which is similar to the mechanism of the commercial Atomic Force Microscope by which to measure the nanoscale sample topography through controlling the tip-sample interaction force. A simple and low cost micro machining device which can control the normal force is established. With the controlled normal force, the effects of the edge forward and face forward machining directions on the grooves' topography is studied. Moreover, the edge forward scratching direction is more suitable for the controlled normal force scratching process than the face forward scratching direction. Finally, the machined microsquares of aluminum alloy (2A12) surface is used as the Surface-enhanced Raman Scattering (SERS) substrate with the Rhodamine 6G (R6G) probe molecule as the detecting target in the present study. Experimental results show that using this simple low cost device, the perfect microstructures can be achieved by the controlled normal force machining method.