topology tagged posts

MIT chemists have designed a polymer that can reversibly switch from a large structure (orange spheres) to the smaller blue shapes, in response to light.
Image: Demin Liu/Molgraphics

New material reversibly changes its structure in response to different wavelengths of light. MIT researchers have designed a polymer material that can change its structure in response to light, converting from a rigid substance to a softer one that can heal itself when damaged.

“You can switch the material states back and forth, and in each of those states, the material acts as though it were a completely different material, even though it’s made of all the same components,” says Jeremiah Johnson, an associate professor of chemistry at MIT, a member of MIT’s Koch Institute for Integrative Cancer Research and th...

Applying a magnetic field to PdCoO2, a non-magnetic metal, made it conduct 70% more electricity, even though basic physics principles would have predicted the opposite. Credit: Eiri Ono/Kyoto University

Applying a magnetic field to a non-magnetic metal made it conduct 70% more electricity, even though basic physics principles would have predicted the opposite. Insights from pure mathematics are lending new insights to material physics, which could aid in development of new devices and sensors. “We never expected that magnetoresistance could be lowered even further in the compound we tested, because in theory it should have increased,” says Kyoto University study author Shingo Yonezawa.

Applying a magneticfield to metals affects how well they are able to conduct electricity...