The Nanometer Imaging and Manipulation System (NIMS) augments the nanoManipulator system (nM) with a scanning electron microscope (SEM), using projective texture mapping and manual alignment of SEM and AFM data sets to enable viewing during direct manipulation of samples inside the SEM. The goal is to use visualization hardware and software to combine the two microscopes into one virtual microscope that combines the capabilities of each and mitigates their limitations.

The NIMS incorporates an AFM into a Hitachi S4700 SEM, a 1.5 nm resolution instrument that enables electron microscope imaging during AFM manipulation. This effectively "turns the lights on" for the user while they are manipulating samples.

The image to the right shows the overview of AFM and SEM scans of the same area, a carbon nano-tube that was draped between two raised electrodes and then broken. The simplest combination of the two data sets is shown here: the data sets were aligned by hand and the SEM laid over the underlying AFM topography using projective texture mapping. The user can adjust the relative mixture of the two data sets.

Begun in 1998, this system has been used to perform experiments on carbon nanotubes and their use in actuating devices (from MEMS to NEMS). [1-3]

New interaction modes have been added to those of the standalone nM to support experiments on fragile structures. One enables control of the AFM probe in 3 dimensions, rather than keeping it always touch-ing the surface. Another provides the ability to drop down onto the surface from above and measure the position offset of an object as the force was uniformly increased and then decreased (force curves).

A method of calibration between SEM and AFM images has been developed that enables the system to show the AFM probe in its proper 3D location compared to the AFM scan. The method uses manually selected corresponding points in the AFM and SEM images to solve for the transformation between the images. This has been extended to include calibration between the AFM probe position, the SEM image, and a geometric model of the surface being studied to enable manipulation experiments on fragile samples without requiring a complete AFM scan of the sample.

Projective texture mapping is used to display AFM scan, SEM image, surface model, and AFM probe position within the same image to provide an optimal understanding of the sample to enable planning of intricate manipulations and electron beam lithography.

References

[1] Williams, P.A., S.J. Papadakis, M.R. Falvo, A.M. Patel, M. Sinclair, A. Seeger, A. Helser, R.M. Taylor II, S. Washburn, and R. Superfine, Controlled placement of an individual carbon nano-tube onto a microelectromechanical structure. Applied Physics Letters, 2002. 80(14): p. 2574-2576.

[2] Williams, P.A., S.J. Papadakis, N.E. Snider, H. Deniz, M.R. Falvo, S. Washburn, R. Superfine , and R.M. Taylor II, "Progress on Field Emission Studies of Individual, Cantilevered Multi-walled Carbon Nanotubes", presented at American Physical Society March Meeting 2002 in Indianapolis (2002).

[3] Williams, P.A., S. J. Papadakis, A. M. Patel, M. R. Falvo, S. Washburn, and R. Superfine, Tor-sional Response and Stiffening of Individual Multiwalled Carbon Nanotubes. Physical Review Letters, 2002. 89(25): p. 25502-1 - 25502-4.

For more information

See Taylor's talks in Taiwan in the Fall of 2002 and various publications in the dissemination web page.