Harvard develops atomic MRI

A molecular MRI system that scans at the nanoscale has been developed by a team of physicists at Harvard University, the institution announced yesterday.

The Cambridge, Mass., university is introducing it as a system that can image the 3D atomic structure of molecules. Scientists published a paper about the technology last month in Nature Nanotechnology.

“What we’ve demonstrated in this new paper is the ability to get very high spatial resolution, and a fully operational MRI technology,” said research lead Amir Yacoby, PhD, as reported by the college. “This work is directed toward obtaining detailed information on molecular structure. If we can image a single molecule and identify that there is a hydrogen atom here and a carbon there … we can obtain information about the structure of many molecules that cannot be imaged by any other technique today.”

The system’s scans at resolutions far greater than conventional systems. It is not yet ready to image inside a single molecule, but that is a goal. Yacoby was reported by Harvard’s Gazette to have said that the technology functions just like a conventional MRI, but on a miniaturized scale and with added functionality borrowed from quantum computing. The magnet is actually 300 times smaller than a red blood cell—just 20 nanometers across, but it puts out a magnetic field gradient that is about 100,000 bigger than the best of conventional MR imaging systems. This means the resolution is still smaller than even one nanometer.

“Our current system is already capable of imaging individual electron spins with sub-nm [subnanometer] resolution,” he added. “The goal, eventually, is to put a molecule in proximity to our NV center to try to see the components within that molecule, namely the nuclear spins of the individual atoms composing it. This is by no means an easy task, since the nuclear spin generates a signal that is 1,000 times smaller than that of the electron spin … but that’s where we’re headed.”