Abstract: Radiation dosimeters that are based on carbon materials such as carbon powder, carbon fibers, carbon nanoparticles and carbon nanotubes are developed. The dosimeter may contain a singular element or multiple sensing elements that are arrayed in 1-D, 2-D and 3-D formations. Each sensing element is made up of two electrodes with carbon materials deposited between the electrodes. The sensing elements may be deposited on flexible substrates to create flexible dosimeters. In addition, the carbon sensing materials may be deposited onto transparent substrates to achieve a transparent dosimeter. Transparent and/or flexible dosimeters can be fabricated with the carbon materials. The sensing elements are connected to external power sources. As the elements are exposed to radiation beams, the change in resistivity or conductance of the carbon materials is measured by current detection circuitry.