Design and Validation of a Low Cost High Speed Atomic Force Microscope

The Atomic Force Microscope (AFM) is an important instrument in nanoscale topography, but it is expensive and slow. The authors designed an AFM to overcome both limitations. To do this, they used an Optical Pickup Unit (OPU) from a DVD player as the laser and photodetector system to minimize cost and they did not implement a vertical control loop, which maximized potential speed. Students will be able to be use this device to make nanoscale measurements and engage in micro-engineering. To prototype this idea, the authors tested an OPU with a silicon wafer and demonstrated the ability to consistently distinguish different distances based on the OPU output. Additional testing was done in order to measure the sensitivity of the OPU using a more robust signal conditioning system. The result of their work is that the system they designed has a resolution of 65 nm on static samples and 1 μm on dynamic samples. Further work is needed to improve the resolution of this system, reduce noise, calibrate the system, and minimize drift.