Formation of large-area stretchable 3D graphene-nickel particle foams and their sensor applications

Stretchable sensors are essential and important for the new-type stretchable intelligent electronic devices. Three-dimensional (3D) graphene foams are attractive to increase the sensitivity and stretchability, benefiting from a high specific surface area and mechanical strength. Herein, 3D graphene/nickel particles (Gr-NiP) peasecod foams, which were fabricated using CVD and stamp-transfer processes, are proposed and used for stretchable sensor applications. The existing nickel particles, covered by graphene layers, are useful for the formation of 3D nanostructures and separated from each other for stretchable applications. A stretchability (3) of such Gr-NiP foams of up to 80% can be achieved. A low limit of detection (< 1%) and excellent linearity (R-2 = 0.997) are also present. Sunken ravines between the Ni particles provide favorable sites to grow Ag nanoflowers (AgNFs), which can enhance the electromagnetic coupling for SERS application. Such stretchable substrates can be used as ultrasensitive biosensors to detect the molecules on the surfaces of any shape.