Measuring changes in position at the atomic scale

The NX NanoSensor from Queensgate is claimed to deliver sensitivity levels that are able to measure changes in position to an atomic scale. This state-of-the-art non-contact position measuring system relies on two sensor plates - a target and a probe, which between them form a parallel plate capacitor. Through the use of an appropriate electronic controller, the spacing of these two plates can be accurately ascertained. Among the key applications for the NX NanoSensor are stage feedback, vibration measurement, metrology, deformation measurements, precision manufacturing, drift measurement, precision beam steering and microscopy.

It is said that positions can be determined to a margin of better than 7pm, with a linearity to 0.02% and a bandwidth from 50Hz up to 10KHz. Working in tandem with the NX NanoSensor, the NS2000 controller module is said to measure any changes in the parallel plate capacitance and subsequently produces an analogue voltage that is directly proportional to the difference in position of the target and probe sensor plates.

The non-contact measurement and non-self-heating mechanism means that NX NanoSensor products do not impact the values they are measuring. Furthermore, they use a non-hysteretic technique, meaning the position is repeatable. Numerous material options can be used in their construction; Super-Invar, Zerdur, aluminium, stainless steel and ceramic - allowing thermal properties to be matched to the stability required by the specific application, in order to safeguard against position drift. Ultra high vacuum, radiation hardened, non-magnetic and cryogenic variants can be specified.