The images below demonstrate our early attempts in positioning colloidal particles. The image on the left shows the initial (and random) arrangement of the particles. With the techniques we have developed, we were able to ‘push’ these particles around to make the final arrangement shown on the right. 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. This image was obtained in the early Summer of 1996.
Reference: C. Baur, B. C. Gazen, B. Koel, T. R. Ramachandran, A. A. G. Requicha, and L. Zini, “Robotic Nanomanipulation with a Scanning Probe Microscope in a Networked Computing Environment”, 4th Int’l Conf. on Nanometer-Scale Science & Technology, Beijing, P. R. China, September 8-12, 1996. Published in J. Vacuum Sc. & Tech. B, Vol. 15, No. 4, pp. 1577-1580, July/August 1997. Online here.