The images below demonstrate one of our first attempts at positioning colloidal Au particles on a Si substrate. The substrate is coated with a silane self-assembled monolayer. The image on the left shows the initial (and random) arrangement of the particles. The final square arrangement shown on the right was produced by pushing the Au nanoparticles with the AFM tip. The manipulation and imaging were carried out in air at room temperature. We used a non-contact AFM mode to get the images. The ‘pushing’ was achieved by turning off the z-feedback temporarily in a single-line scan.
Reference: A. A. G. Requicha, C. Baur, A. Bugacov, B. C. Gazen, B. Koel, A. Madhukar, T. R. Ramachandran, R. Resch and P. Will, “Nanorobotic assembly of two-dimensional structures“, Proc. IEEE Int’l Conf. on Robotics & Automation, Leuven, Belgium, pp. 3368-3374, May 16-21, 1998.
