A Functional 3D- and Inkjet-Printed Hou...

Processes of the category of rapid-prototyping, such as the considered 3D- and inkjet printing, provide new flexibility for the design of smart and functional housings and packages.  These  processes  also  enable  individual  optimization  of  sensors  and packages  due  to  these  design  flexibilities.  Other  advantages  are  the  relatively  low costs for small batch series as well as short development times. For the considered application of a Fourier Transform InfraRed (FTIR) spectrometer, a  functional  package,  which  holds  an  inkjet-printed  capacitive  position  sensor,  is designed. The package is made of 3D-printed copper. The copper is then coated with insulator onto which the inkjet-printed silver electrodes are subsequently printed. The whole structure builds up the capacitive position sensor. This sensor determines the position  of  an  electrostatically  actuated  Micro  Electro  Mechanical  System  (MEMS) mirror  with  nanometer  accuracy  at  high  bandwidths  and  large  position  offset.  The MEMS  mirror  is  part of  a  Michelson  interferometer  setup and  driven  at  resonance. The  large  oscillation  amplitude  and  high  required  resolution  at  resonance  of  the MEMS mirror is also the reason for high demands on the position measurement.