Synthesis of carbon nanospheres for the development of inkjet-printed resistive layers and sensors

Unitary carbon nanoparticles with a well-defined shape and a range of diameters between 50 nm and 300 nm have been synthetized from the pyrolysis of resorcinol formaldehyde copolymer. This divided solid has a molecular organization similar to carbon black with a more regular shape and a higher diameter. Thus, carbon nanospheres appear to be adapted to the development of accurate sensors. Inkjet-printable dispersion was prepared with this material and a mixture of N-methyl-2-pyrrolidone and N-cyclohexyl-2-pyrrolidone. This ink is the proof of concept that it is possible to form continuous layers on polyimide flexible substrate with resistive properties which exhibit temperature sensitivity.