Overall Additive Manufacturing of Capacitive Sensors Integrated into Textiles: A Preliminary Analysis on Contact Pressure Estimation

Printed electronics approaches in deploying sensors offers several advantages over traditional methods, including their capability to be integrated into flexible substrates, including textiles. Additionally, printed sensors can be manufactured at relatively low cost and overall include sustainable materials, making them a more accessible option for a wider range of applications. Utilizing additive manufacturing techniques like stereolithography and aerosol jet printing, this work focused on creating fully printed capacitive pressure sensors within textiles. The sensors were designed as planar capacitors with micro-structured dielectrics to enhance linearity and measurement range. Three devices, incorporating 3D pyramidal structures, were produced and characterized under varying loads; the dielectric part was realized by using stereolithography and directly incorporating fabric on the top/bottom sections, whereas carbon-based ink was then deposited to produce the conductive plates and connection pads. Results indicated primarily capacitive behavior up to 10 MHz, with tunable capacitance affected by surface areas and air/resin ratio; hysteresis was also observed, revealing inherent non-linear behavior. These main findings provide important insights into the feasibility of the design and the additive manufacturing process. This innovation holds promise for applications in a variety of fields, including safety and sports.