Ultra-thin polymer Bragg grating sensor foils

Polymer Bragg grating sensors rely on the same principle as fiber-based grating sensors: a Bragg grating is a type of wavelength reflector written in a short segment of a light guiding channel which reflects particular wavelengths of the light. External parameters influence the reflected wavelength and as such strain and temperature can accurately be measured.

Unique selling points of the polymer sensing foils:

  • The sensing foil can be very thin (a few tens of microns) and therefore easily be integrated (e.g. laminated)
  • The foil can contain many sensors to allow multiplexing, or even sensors in different directions to allow multi-axial strain sensing
  • By selecting the appropriate type of polymer, the sensor functionality can be optimized, e.g. more towards strain sensing or towards temperature sensing


Case: Polymer sensor foils embedded in glass fiber reinforced composite

An epoxy-based sensor foil was embedded in an epoxy-based glass fiber reinforced composite and used for strain sensing

  • 50 μm thin and 100 μm thin sensor foils were successfully embedded
  • Strain sensitivity was similar to that of surface mounted sensor foils
  • Dynamic loading tests are currently ongoing and initial results are promising


Case: Ultra-sensitive temperature sensing

An Ormocer®-based polymer (hybrid organic-inorganic specialty polymer) sensor was designed for a very high temperature sensitivity

  • A sensitivity of 250pm/K was found, which would allow detecting milliKelvin temperature changes