Fabrication of graphene reinforced silicone-based 3D printed tactile sensor: An approach towards an applicable piezo-sensor

Highly sensitive, wearable, and durable tactile sensors are vital for developing smart robots, human-machine interfaces, and health monitoring systems. Although current techniques for developing tactile sensors achieve high performance, they suffer from fabrication complexity, complex working principle, short lifetime, low stretchability, and, in some cases, low sensitivity. Herein, we present a facile, cost-effective, and scalable method for creating a 3D printed composite film of a tactile sensor made of natural rubber (NR) coated photosensitive elastomer resin (PR)/graphene nanoplatelet composite film. The addition of graphene nanoplatelet (GnP) not only improves the mechanical properties, stretchability, and flexibility of the PR/GnP composite film but also becomes responsible to produce the piezoresponse even under slight mechanical deformation in the flexible film. Furthermore, the proposed NR coating nullifies the possibility of producing interfering triboelectricity during its application as a highly sensitive pressure sensor. It also provides a low-cost protective layer for the active material as well as the flexibility of the overall device.