For 20 years, Jenny Hoffman built powerful microscopes, taking beautiful pictures of electrons and atoms. But as amazing as those images were, she felt there was something missing by being simply an observer of existing materials. Then several years ago, she changed her research path. She began to create and manipulate new materials.
Hoffman, professor of physics at Harvard University and associate fellow at the Canadian Institute for Advanced Research, is particularly interested in superconductors: materials that can carry electricity without losing energy. To date, existing superconductors only work at very low temperatures. Hoffman wants to improve on them by creating a superconductor that could work at room temperature.
A room temperature superconductor could cut energy losses in getting electricity from the power plant to devices. It would also expel a magnetic field, making it useful in levitating magnetic trains or in medical applications such as MRI imaging.
While many researchers are working on superconductors, Hoffman is studying layered combinations of materials to create unique properties. Her materials are like the sandwiched pages of a book: two dimensional flat surfaces that take on new qualities at the interfaces where they meet. The combinations can have properties that are distinct from those of either starting material, says Hoffman.
Hoffman’s goal is to build a machine that could build custom materials atom by atom, giving better flexibility and precision to create complex combinations that could have superconducting properties. She is already building machines that can make a single layer of atoms, and then scan over them with a sharp tip to capture information about them. This tip is so sharp that it is a single atom, and it can also pick up and move other atoms around the surface of the sheet. Expanding this to printing in three dimensions would enable her to print complex materials from the ground up.
“That’s the dream and every bit of it is achievable,” says Hoffman, “but it’s going to require a huge amount of work.”