Abstract: A device produces an electrical signal in response to a stimulus. The device is formed of a flexible substrate including a layer of fibers, for example, paper, and a solution of dispersed carbon nanotubes coated onto and within the fibers, the solution evaporated to leave carbon nanotubes intertwined within the layer of fibers. The carbon nanotubes are functionalized to be optimized for producing an electrical signal for a particular stimulus, where the stimulus includes exposure of the devic…