The Sandia-developed technique coats a cell’s insides with a silica solution to form a near-­‐perfect replica of its internal structure—simplifying a wide variety of commercial fabrication processes from the nano- to macro-scale. The work, reported in the Proceedings of the National Academy of Sciences, uses the nanoscopic organelles and other tiny components of mammalian cells as templates on which to deposit silica. The researchers then heat the cell to burn off its protein. The resultant hardened silica structures are faithful to the exterior and interior features of the formerly living cell, can survive greater pressures/temperatures than flesh ever could, and can perform some functions better than when they were alive, said lead researcher Bryan Kaehr (Advanced Materials Laboratory).

This cell was pyrolized to 900° C in the absence of oxygen, leaving a cell of graphitic carbon and silica. (Image courtesy of Bryan Kaehr)

“It’s very challenging for researchers to build structures at the nanometer scale,” said Kaehr. “We can make particles and wires, but 3-D arbitrary structures haven’t been achieved yet. With this technique, we don’t need to build those structures—nature does it for us. We only need to find cells that possess the machinery we want and copy it using our technique. And, using chemistry or surface patterning, we can program a group of cells to form whatever shape seems desirable.”

UNM professor and Sandia Fellow Jeff Brinker (Self-­Assembled Materials Dept.) added, “The process faithfully replicates features from the nanoscale to macroscale in a robust, three-dimensionally stable form that resists shrinkage even upon heating to over 500° C [932° F]. The refractoriness of these delicate structures is amazing.” Such materials would have substantial utility in fuel cells, decontamination, and sensors.

The work was supported by DOE’s Office of Science. Co-authors are Brinker, Brian Swartzentruber of Sandia and the Center for Integrated Nanotechnologies, and, from UNM, Robin Kalinich, Darren Dunphy, and student Yasmine Awad.

Read the Sandia news release.