Zhiqin Chu

A cell doesn't just lie on a surface: it probes it, pulls it, and pushes it. Until now, instruments could only detect direct forces: how hard a cell presses or stretches its support. But if you grab a cell by the "shoulders" and give it a slight twist, it responds by rotating, and until recently, no one could measure that rotation.

Tiny diamonds with a defect inside can act as ultra-sensitive magnetic field sensors. But to be useful in medicine, they need to be carefully placed on soft, wet, curved surfaces, like a hydrogel bandage or a hair. It's like applying a temporary tattoo to a wet ball: the usual methods either burn the pattern or leave messy residues.

Heat inside a cell is like traffic in a city: on some streets the lanes are wide and traffic flows fast, while in narrow alleys everything gets stuck. Scientists have found a way to map such 'traffic jams' for heat without opening the cell. They took tiny diamonds, so small they are invisible to the naked eye, and placed them on a thin gold plate.