text: Due to the thermal constraints faced by using polypropylene as base material, applications where high sensitivity is needed, long-term temperatures should be below 70 °C, which limits its scope in terms of some potential applications such as the automotive industry. 
  The air voids present in the structure become smaller and higher in pressure as force is applied to the film. This means that the film becomes harder to compress as it goes under more load, meaning that in the sensor mode, the charge output is non-linear, which can make calibrating the sensor difficult.