Three-axis micro-force sensor with tunable force range and sub-micronewton measurement uncertainty

This paper presents the design, fabrication and characterization of the first microfabricated three-axis tunable force sensor with sub-micronewton measurement uncertainty. The sensing range can be electrically tuned from +/-20 μN to +/-200 μN while taking measurements, ensuring optimal sensor characteristics for a large variety of applications. Since the sensor has been pre-calibrated for the entire tuning range the exact sensor gain and its uncertainty is known. Real-time, three degree of freedom force feedback makes this sensor a valuable tool for micromanipulation.