Laser Direct Writing of Flexible Large-Area Graphene Sheet for Electrical Impedance Tomography Based Multimode Sensing Purposes

The high-performance electrical impedance tomography (EIT) based sensors rely on the formation of uniform and large-area conductive sensing layers in a highly efficient and scalable method. In this study, a laser direct writing (LDW) technology is studied to prepare a large-area graphene layer for EIT-based sensors of pressure and temperature measurements. Through the optimization of the LDW parameters, the generated graphene sheet on a polyimide (PI) substrate with a minimized electrical anisotropy of 1.68 has a sensitivity of 1.76 x 10(-4) kPa(-1) for applied pressure and a temperature coefficient of resistance (TCR) of -2.26 x 10(-4)degree celsius(-1). Besides, the EIT sensor demonstrates great potential for temperature and pressure sensing purposes, which can be employed to detect surface cracks and impact damage as well.