Laser-induced graphene in flexible PI/PDMS polymer aiming application in pressure sensors

There is a huge field of research involving graphene, both for the study of its properties and on its countless applications. As a result, graphene with different sizes and morphologies have been obtained by several techniques, as is the case of 3D graphene foams obtained by CVD, chemical routes, and recently by laser-induced graphene (LIG). In this work, a pressure sensor based on LIG, using Polyimide (Kapton) tape adhered to polydimethylsiloxane (PDMS) films as precursor material is manufactured. The laser used to trace the graphene lines is a low cost commercial laser of 405 nm and 500mW. The formation of graphene on the Kapton adhered to PDMS, allows a great flexibility and greater sensitivity to pressure. So, the best parameters were established in thickness, laser scanning speed and focus, to obtain graphene foam traces with good quality and high conductivity for a better response as a pressure sensor. A sheet resistance of 85Ω/□ and pressure sensitivity was obtained.