Material propertiesDevelopment of porous polymer pressure sensors incorporating graphene platelets

Electrically conductive polymer composites (ECPCs) based on porous polymeric matrices of PEBA 4033 incorporating different types of graphene platelets were prepared and tested. PEBA 4033 polymer was mixed with different graphene platelets: grade H5, grade MX and grade C-750. Porous morphology was obtained for the ECPCs prepared with graphene platelets grade MX and H5, while for the grade C-750 only a dense ECPCs was obtained. The porous ECPC loaded with 15 vol.% of graphene M5 exhibited a linear piezoresistive response oin a log-log plot. Some limitations were detected for this ECPC, namely hysteresis and drift due to the poor mechanical properties. The porous ECPC loaded with 15 vol.% M5 was further crosslinked, which improved its mechanical properties but the piezoresistive effect became negligible. The incorporation of carbon black in this ECPC formulation was shown to be much more efficient than crosslinking to improve mechanical properties, but the piezoresistive response became poor.