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This thesis presents the design , development , and testing MEMS based Atomic Force Microscope (AFM ) . The system is capable of measuring the pull -off force measurements on different surfaces . The design is capable of producing a verticalresolution of ~ 2nm .
The MEMS AFM consists of a stand -alone optical head , stepper motor controlled Z stage assembly incorporated with a MEMS XY stage . The shaft end of the stepper motor has a worm gear attached , which takes care of the Z movement .A commercial piezo actuator from Noliacis used . A LabView -based system is used to control the entire assembly . Custom made piezo amplifiers and transimpedance amplifiers are developed .
The MEMS -based AFM has significance in finding the adhesion forces of a surface estimating the surface energy present on the surface . Surface forces in the order of ~21Nn and ~ 11nN are measured for a bare silicon substrate and hydrophobic coated MEMS XY stage . In addition , the results obtained are compared with the results of the force measurements performed on a commercial AFM system (Park XE -100 ) . The signal to noise ratio for the system is calculated and is found to be 40 dB . |
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