Nanoscale Displacement and Strain Measurement

The mechanical testing of micro-electro-mechanical systems (MEMS) and nano-electro-mechanical systems (NEMS) requires precise measurements of displacement and strain in the nanometer scale. Integrated testing devices, including specimens, actuators and sensors, were designed and fabricated to overcome the aligning and gripping difficulties faced by previous separated micromechanical testing apparatuses. The specimens were “dog-bone” shaped and were deformed in-plane by electrothermal actuators based on bent-beam suspensions. The displacement field was obtained by comparing surface topologies, acquired with an Atomic Force Microscope (AFM), of undeformed and deformed specimens using the Digital Image Correlation (DIC) method. The change in capacitance of the integrated capacitive sensors was measured to determine the total displacement. The behavior of the whole device was simulated by ANSYS multiphysics, which agreed well with the measured results.