Scanning Electron Micrograph

The M13 virus is a thin, spaghetti-like strand that infects E. coli bacteria.  With a few careful genetic alterations, however, M13 becomes a tiny factory.  Researchers in Angela Belcher’s Biomolecular Materials Lab have engineered the virus to assemble many practical structures including battery electrodes.

Here, the researchers linked many copies of M13 together to form a dense, three-dimensional mesh.  John Burpo, a graduate student, was curious whether the holes he saw on the surface were also present deep inside the mesh; the answer to this question would affect the potential applications of the material.  To find out, John used a powerful beam of ions to burn deep into the mesh (center), revealing definite holes beneath the surface.