The imaging device has been designed by University of Texas at Dallas physicists and it moves atomic force microscopy away from large, bulky instruments to devices that are small and which have a wider application. Atomic force microscopy refers to a very-high-resolution type of scanning probe microscopy. Such devices have a resolution on the order of fractions of a nanometer (where one nanometer is one-billionth of a meter). This type of microscopy forms images of surfaces using a physical probe that scans the specimen. Here imaging information is gathered by “feeling” or “touching” the surface with a mechanical probe.
In what is a significant development, the U.S. researchers have succeeded in miniaturizing all of the required electromechanical components needed for the microscope down onto a single small chip. This was based on a field of physics called microelectromechanical systems. This involves fabricating micro-size variants of existing technology using modified semiconductor device fabrication methods, as used in the electronics industry for chip manufacture.
The new microscope is 1 square centimeter in size (the size of a dime). The imaging device is attached to a small printed circuit board (no larger than half the size of a credit card). The circuit board contains circuitry, sensors and other miniaturized components necessary to control the movement of the device. The microscope functions by oscillating up and down perpendicular to the sample. With the probe moving back and forth across a sample material, a feedback loop controls the height of that oscillation; and from this an image is formed. The researchers say the device can be made for less than $5,000, cutting the cost of a standard atomic force microscope down from $50,000.
The application of the microscope will be for the electronics industry, to help to develop smaller electronic devices. The new device is described in the Journal of Microelectromechanical Systems, with the research paper titled “On-Chip Dynamic Mode Atomic Force Microscopy: A Silicon-on-Insulator MEMS Approach.”
