The cells are painted with silicic acid, which embalms the organic matter down to the nanometer level. The silica then acts as armor. When heated to around 400c, the protein with the cell evaporates, but the silica remains intact.
"Our zombie cells bridge chemistry and biology to create forms that not only near-perfectly resemble their past selves, but can do future work," said lead researcher Bryan Kaehr. The zombie apocalypse is going to be more terrifying than anyone originally thought.