Varmeelementer, varmevekslere og varmeelementrækker

A heater element 10 comprises a substrate 12; a first electrode 14 and a second electrode 16 disposed on the substrate and a carbon nanomaterial-containing layer 18 disposed on the substrate, the carbon nanomaterial-containing layer being disposed between and electrically connected to the first and second electrodes. The carbon-nanomaterial containing layer may comprise graphene or carbon nanotubes or a mixture of both and may be applied in the form of a conductive ink or similar dispersion, e.g. by spraying, printing or painting. Also provided are a heat exchanger, a heater element array, integrated devices, and manufacturing methods.