A Robust 3D- and Inkjet-Printed Capacitive Position Sensor for a Spec...

For  the  considered  application  of  a  Fourier  Transform  InfraRed  (FTIR)  spectrometer,  afunctional package and an inkjet-printed capacitive position sensor are built. The package is madeof  3D-printed  copper.  The  copper  is  then  coatedwith  insulator  onto  which  inkjet-printed  silverelectrodes  are  subsequently  applied.  The  whole  structure  builds  up  a  capacitive  position  sensor.The  target  application  is  to  measure  the  positionof  an  electrostatically  actuated  Micro  ElectroMechanical System (MEMS) mirror with nanometer accuracy at high bandwidths and large positionoffset.  The  MEMS  mirror  is  part  of  a  Michelson  interferometer  setup  and  driven  at  resonance.The large oscillation amplitude and high requiredresolution at resonance of the MEMS mirror arealso  the  reason  for  high  demands  on  the  position  measurement.  Robustness  against  disturbingfrequencies is assured by employment ofa carrier-frequency read-out structure.