Electromechanical Transducers of Sensor Micro- and Nanosystems: Physical Foundations and Scaling Effects. Part 2. Detectors, Noise Sources and Characteristics
In the second part of the review devoted to analytical presentation of capacitive, piezoelectric, opto-rntegrated, and electron tunneling detectors of mechanical motion in NEMS transducer elements it is shown that tunneling detectors are most promising. However, side physico-chemical (adhesion and capillary) effects and forces begin to act significantly in these detectors. Different fluctuation processes such as thermomechanical and temperature fluctuation, adsorption/desorption processes in the sensing mechanical elements and electrical fluctuation processes in tunneling detectors begin playing a significant role at the transition to nanoscale as well. These processes determine mostly noise character and magnitude and, respectively, sensitivity and resolution of sensor NEMS.