Polarization domain information on insect wing chitin using the scanning pyroelectric microscope (SPEM)

Scanning Pyroelectric Microscopy (SPEM) at micrometer resolutions has been employed to study permanent polarity and its spatial organization in various insect wings containing chitin, one of the most abundant biopolymers. Both measurements on wings of houseflies and wasps revealed a well defined pyroelectric response, showing a multidomain polarization pattern at several length scales, from millimeter sized domains in the wing veins, to 20 micrometer sized domains in the membranes. The size of the smaller domains correlates well with the average chitin fiber length of 18 micrometers.