Graphene
The theory of graphene was first explored by Wallace in 1947 as a starting point for understanding the electronic properties of 3D graphite. The emergent massless Dirac equation was first pointed out by Semenoff, DiVincenzo and Mele. The earliest TEM images of few-layer graphite were published by Ruess and Vogt in 1948. An early, detailed study on few-layer graphite dates to 1962 when Boehm and colleagues reported producing monolayer flakes of reduced graphene oxide. Efforts to make thin films of graphite by mechanical exfoliation started in 1990, but nothing thinner than 50 to 100 layers was produced before 2004. Initial attempts to make atomically thin graphitic films employed exfoliation techniques similar to the drawing method. Multilayer samples down to 10 nm in thickness were obtained.
Phonograph cylinder
Following seven years of research and experimentation at their Volta Laboratory, Charles Sumner Tainter, Alexander Graham Bell and Chichester Bell introduced wax as the recording medium and engraving, rather than indenting, as the recording method. In 1887, their "Graphophone" system was being put to the test of practical use by official reporters of the US Congress, with commercial units later being produced by the Dictaphone Corporation. After this system was demonstrated to Edison's representatives, Edison quickly resumed work on the phonograph. He settled on a thicker all-wax cylinder, the surface of which could be repeatedly shaved down for reuse. Both the Graphophone and Edison's "Perfected Phonograph" were commercialized in 1888. Eventually, a patent-sharing agreement was signed and the wax-coated cardboard tubes were abandoned in favor of Edison's all-wax cylinders as an interchangeable standard format.