Nanoelectromechanical Position-Sensitive Detector with Picometer Resolution

Subnanometer
displacement detection lays the solid foundation for
critical applications in modern metrology. In-plane displacement sensing,
however, is mainly dominated by the detection of differential photocurrent
signals from photodiodes, with resolution in the nanometer range.
Here, we present an integrated nanoelectromechanical in-plane displacement
sensor based on a nanoelectromechanical trampoline resonator. With
a position resolution of 4 pm/Hz for a
low laser power of 85 μW and
a repeatability of 2 nm after five cycles of operation as well as
good long-term stability, this new detection principle provides a
reliable alternative for overcoming the current position detection
limit in a wide variety of research and application fields.