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Capacitive Sensors for Nanopositioning - Nanopositioners

Nanometer level resolution over short distances is possible with capacitive sensors. The sensor uses the structure of stage as the target, so it is much more compact than a linear encoder. Capacitive sensors provide sub-nanometer resolution at a fraction of the cost of laser distance measuring interferometers.

Capacitive sensors from MicroSense are ideal for providing position feedback in piezo motor or voice coil driven nanopositioning applications, and as position sensors in tip-tilt mechanisms. They can be used as the feedback sensor in the servo loop, or as an independent position sensor. Nanopositioners are typically one, two or three axis positioners which provide travels in the order of a few hundred micrometers per axis. Nanopositioners are generally constructed with flexural ways machined from solid blocks of metal, in order to provide very pure motion with minimal off axis motion. Actuators are either piezo motors or voice coils. Capacitance sensors provide the following advantages when used as feedback devices in nanopositioners:

Benefits

  • The resolution of the capacitance sensor is at the nanometer level.
  • For scanning applications, capacitance sensors provide exceptionally linearity, and eliminate the cyclical errors associated with optical encoders.
  • For applications requiring high stability in position, capacitance sensors are very stable, and can be built from materials which have essentially zero thermal dissipation.

High Bandwidth Capacitive Sensors for Fast Tool Servo

Fast Tool Servo feedback sensorFast Tool Servo systems are used in a variety of machining applications to machine non-rotationally symmetric surfaces and to create a variety of surface structures. A fast tool servo is a tool holder module with a high performance linear actuator that oscillates the tool at a particular bandwidth.

Capacitance sensors from MicroSense, used to provide servo system feedback, offer both the high bandwidth and the high resolution necessary for fast tool servo applications. Our model 8810 is available with bandwidths up to 20 KHz.

 

 

 

Recommended Products
Demodulator Sensor Series Application
Model 4810 2800 series Servo feedback for nanopositioners
Model 8810 2800 series Servo feedback for nanopositioners
Model 8810, 20 KHz version 2800 series Fast tool servo
Model 6810 6000 Series Ultra high resolution nanopositioning