Tim Luttermann

Development of a Force Microsensor for Robot-based Nanohandling

Abstract The process of electron beam induced deposition was used to create sensor structures for strain measurements with outer dimensions of 20 μm by 30 μm. The sensor principle was derived from classic macroscopic strain gage sensors. Therefore, electrically conductive lines with a width of 200 nm were directly deposited on an SiO 2 coated silicon wafer by writing them with the electron beam of a scanning electron microscope and in the presence of an organometallic tungsten precursor. To determine the properties of the sensor structure, the electric noise was measured and compared to a constantan strain gage and a semiconductor strain gage. From this noise voltage, the best achievable mechanical resolution for every strain gage type is determined. The electric resistance of the sensor structure was measured at defined strain and compression to determine the gauge factor which is needed to calculate the value of arbitrary strain from measured resistances. Long time period measurements of the electrical resistance showed effects of a burning-in process, aging and wear of the sensor structure, which were analyzed in the last part of this work.