X-ray generation using carbon-nanofiber-based flexible field emitters

Carbon nanofibers were grown on flexible polyimide substrates using an ion-beam sputtering technique. Field emission measurement showed a fairly low threshold voltage of 1.5 V/mu m with a current density of 1 mu A/cm(2). The field enhancement factor was determined to be 4400. The emitter showed resilience when exploited as a high voltage electron source for x-ray generation. The x-ray generated by the flexible emitter is capable of delivering fine images of biological samples with superior sharpness, resolution, and contrast.