BS in Materials Engineering
Materials Engineering Department
The design and implementation of a micro-force displacement system was completed to test various Micro-Electro-Mechanical Systems (MEMS) devices including silicon diaphragms and cantilevers. The system utilizes a World Precision Instruments Fort 10g force transducer attached to a World Precession Instruments TBM4M amplifier. A Keithley 2400 source meter provided data acquisition of the force component of the system. A micro prober tip was utilized as the testing probe attached to the force transducer with a tip radius of 5um. The displacement of samples was measured using a Newport M433 linear stage driven by a Newport ESP300 motion controller (force readings at constant displacement intervals). An additional 3 linear stages were used to provide X and Y-axis positioning of samples beneath the probe tip. The system components were mounted to an optical bench to provide stability during testing. C# was used to deliver the code to the individual components of the system. In addition the software provides a graphic user interface for future users that includes a calibration utility (both X/Y and force calibration), live force-displacement graph, motion control, and a live video feed for sample alignment. Calibration of the force transducer was accomplished using an Adam Equipment PGW153e precision balance to assign force values to the voltage data produced from the transducer. Displacement calibration involved the use of a microscope calibration micrometer. The transducer was characterized to provide a resolution of +/- 0.5 milligrams (4.9uN) with the ability to characterize samples with flexibility greater than 8.2372 mg/um. The displacement resolution of the system was determined to be 35 nm per step of the linear stages. The system was tested on a 4.4mm2 diaphragm to characterize the force displacement of the device.