Humidity and Temperature Sensors on Plastic Foil for Textile Integration

Low-power humidity and temperature sensors fabricated on Kapton® polyimide sheets are successfully woven into textile using a conventional weaving machine. During machine weaving electronic devices undergo mechanical deformation, mostly due to bending, and shear forces. Bending radii in textiles can be as small as 165 μm during weaving, corresponding to a strain of about 15%. This imposes stringent mechanical requirements on the textile integrated sensors. In this work, we present gas sensors on plastic foil with encapsulated active area for protection during stripes dicing, weaving, and operation. Basic tests with CAB and PDMS sensing layers on capacitive transducers showed that woven sensors survive the weaving process without loss of functionality.