[ w y P h y s . c o m ]

Nanoscience in a Suitcase




Contents

Introduction
Videos



Introduction

The images on the right of the descriptions below are from a talk I gave at the end of this summer (some of these slides were also used in the talk I gave at the Fall MRS meeting).

The Nanoscience in a Suitcase project consists of the equipment shown in the slide at right which all fits into a Pelican 1620 case with outside dimensions: 63 cm x 49.2 cm x 35.2 cm.

The two devices, the NanoManipulator and the portable AFM, are products of 3rdTech and Nanosurf respectively. The NanoManipulator was initially designed to work with Veeco's Explorer AFM, but with the idea that it could be interfaced with other SPMs in the future. In order to interface the NanoManipulator with the Nanosurf AFM I communicated with programmers from both companies and modified source code for the NanoManipulator.





Our primary interest in combining the two devices was to improve the quality of our Nanoscience outreach education. Ordinarily when giving a talk to the public, or to high school or college classes, there would be no means to give a hands-on type of demonstration. Explanation of AFM uses and operation would be abstract, covering the information shown in the slide at right along with some images of typical AFM scans.





The Nanosurf AFM makes it possible to actually demonstrate atomic force microscopy in action. When students can see the AFM, and see the sample that is to be scanned, it makes it easier to understand the scales involved and the physical processes at work.

The slide at right is a little misleading in that it implies that the NanoSurf can only be used for low-precision research. Under proper research conditions (sufficient isolation, etc.) it is possible to take higher-precision measurements with the Nanosurf, however in our demonstration usage we are limited primarily to examining features on the micron and upper nano scale.





The NanoManipulator provides a 3D interface to the AFM. It makes understanding sample surface topography intuitive with a 3D scaled-up reproduction of the surface as it is scanned as well as a tactile reproduction of the surface provided by a haptic input device.

The NanoManipulator software functions as an alternative interface to the microscope - it allows for definition of scan regions as well as standard operating parameters such as setpoint, scan rate, resolution, etc. The NanoManipulator also provides additional tip control functionality for surface modification. It is possible to move features across the sample surface, perform nanolithography, and other custom modifications in real time with the horizontal positioning of the tip following movements of the user's hand as recorded by the haptic input device. Although the AFM cannot perform raster scans at the same time (since the tip is following the user's motions), data read from the tip is processed by the NanoManipulator software and fed back to the haptic device which in turn provides force-feedback to the user. In this way, the user can feel the sample as it is being modified.





My job has been to translate the functionality of the NanoManipulator into information that can be understood by the Nanosurf AFM and vise-versa. The slide at right shows pseudo-code for reading in scanline data from the Nanosurf AFM, converting it to a format understood by the NanoManipulator, and then transmitting that data to the NanoManipulator. The real source code is obviously more complicated than what is shown, but because of a non-disclosure agreement we have with 3rdTech (my code is a modification to their proprietary software), I cannot display the actual code or disclose any details of how it works.

The coding was done in Microsoft Visual C++.




Videos

There are multiple videos that can be seen by clicking the links directly above the flash movie. Once a movie is playing there are standard movie controls underneath the flash movie.



Videos: Overview | Devices in Action | Close-up


This movie shows the hardware used. From right to left the components are:

  • The AFM stage and probe
  • The AFM controller
  • The haptic input device
  • The laptop
  • Additional input device (far left)



This movie demonstrates that movement of the haptic input device is mirrored in the virtual environment displayed on the computer screen.



This movie shows what happens graphically when the NanoManipulator is in touch-mode As the blue virtual probe is dragged across the surface, the haptic input device applies force feedback to keep the user from being able to pierce through the surface. The result is that the user can "feel" features.

The movie also shows placement of measure lines in order to perform standard measurements on the sample (see the screenshot below for further explanation).













The following screenshot shows the calibration grating that was being scanned in the movies above:

The text in the lower-left corner shows the dimensions of the scan region. The text in the upper-right corner shows distances between measure lines. The text between the red and yellow bar in the upper-right corner shows the relevant distances between the red and yellow measure lines located in one of the depressed regions of the sample. Dxy is the planar (horizontal) distance between the two measure lines while Dz is the vertical distance.




Back to the main page...