Electromagnetic radiation detecting and sensing systems using carbon nanotube fabrics and methods of making the same are provided. In certain embodiments of the invention, an electromagnetic radiation detector includes a substrate, a nanotube fabric disposed on the substrate, the nanotube fabric comprising a non-woven network of nanotubes, and first and second conductive terminals, each in electrical communication with the nanotube fabric, the first and second conductive terminals disposed in space relation to one another. Nanotube fabrics may be tuned to be sensitive to a predetermined range of electromagnetic radiation such that exposure to the electromagnetic radiation induces a change in impedance between the first and second conductive terminals. The detectors include microbolometers, themistors and resistive thermal sensors, each constructed with nanotube fabric. Nanotube fabric detector arrays may be formed for broad-range electromagnetic radiation detecting. Methods for making nanotube fabric detectors, arrays, microbolometers, thermistors and resistive thermal sensors are each described.