Thermoformed electronic skins for conformal tactile sensor arrays

Robots and prostheses are increasingly designed with curvilinear surfaces for functional, aesthetic, aerodynamic, and safety reasons. Electronic skins (e-skins) capable of sensing contact location and pressure across complex, non-developable surfaces are essential for empowering next-generation robots with tactile awareness. This will facilitate safe and natural human-machine interactions while enhancing object manipulation capabilities. Despite the evident advantages of conformal e-skins, current fabrication methods face significant challenges in realizing their full potential. In this paper, we introduce thermoforming as a technique to efficiently fabricate tactile sensitive e-skins that conform to curvilinear surfaces. The performance, repeatability and uniformity of the sensors are characterized in detail. We also present a custom calibration pipeline where accurate digital replicas of conformal e-skins are generated for use in simulations. Finally, we demonstrate the benefits of 3D e-skins in a tool manipulation task.