High-Accuracy Digital-To-Analog Actuators using Load Spring Compensating Fabrication Errors

We present a new high-accuracy digital-to-analog (DA) actuator using a load spring, specially designed to compensate displacement errors caused by fabrication errors. The compensated linear DA actuator is capable to change the slope of input-output modulation line in order to compensate fabrication errors. We design, fabricate, and characterize three different prototypes: one uncompensated design and two compensated designs respectively for a specific value and for a given range of fabrication error. The compensated linear DA actuators show the output displacement errors of -0.20 plusmn 0.23 mum and - 0.13plusmn0.18 mum, respectively, reduced by 64.3% and 76.8% of the output displacement error, 0.56plusmn0.20 mum, produced by the conventional uncompensated linear DA actuator. We experimentally verify the fabrication error compensation capability of the present compensated linear DA actuators, thus demonstrating high-accuracy actuation performance immune to fabrication errors.