Due to the lack of cost effective sensors that provide both high-resolution and wide bandwidth, recent research has also considered the collaborative use of multiple sensors. For example, in reference [40] a piezoelectric strain sensor and capacitive sensor were combined. The feedback loop utilized the capacitive sensor at low frequencies and the piezoelectric sensor at high frequencies.This approach retains the low-frequency accuracy of the capacitive sensor and the wide bandwidth of the piezo sensor while avoiding the drift from the piezo sensor and wide-band noise from the capacitive sensor. The closed-loop noise was reduced from 5 nm with the capacitive sensor to 0.34 nm with both sensors. Piezoelectric force sensors have also been used for high-frequency damping control while a capacitive, inductive or strain is used for tracking control