Crystals that move under light could serve as drug-delivery microrobots

We expect crystals to be rigid and brittle, so scientists were shocked when some of their crystals seemed to come alive under a microscope. They hope to use the unusual behavior to make tiny machines powered by light that could deliver targeted medicine inside the body.

Watch an interview with the researchers 

Read an ACS press release about this research: Molecular crystal motors move like microbes when exposed to light

Source Article

“Advancing photomechanical crystals: Light-powered continuous motion of molecular crystals”
Presented at ACS Spring 2024 on March 19, 2024
Presenter: Rabih O. Al-Kaysi, Ph.D.
Principal investigators: Rabih O. Al-Kaysi, Ph.D., and Christopher J. Bardeen, Ph.D.

Transcript

Christopher J. Bardeen, Ph.D.: So he just sent me videos, and I saw the videos of these crystals moving and doing these sort of intricate motions under light, and I didn't believe it at all.

Narrator: Believe it or not, these swirling ribbons are actually crystals. 

We expect crystals to be rigid and brittle. So scientists were shocked when crystals they grew for solar energy research seemed to come alive under a microscope.

Christopher J. Bardeen, Ph.D.: We realized they were doing photochemistry inside the crystal and that that photochemistry was turning into motion.

Narrator: The crystals are made from an organic molecule, more than a billion of them packed tightly together to form a tiny wire. Each molecule has a carbon-carbon double bond that works like an axle and allows part of the molecule to twist when it absorbs energy from light. That forces the other molecules to shift in response. And then the crystals start to dance.

Rabih O. Al-Kaysi, Ph.D.: So instead of breaking and scattering all over the place, they expand. And this is something interesting. I'd say look at a bunch of hair — just hair. Go to a barbershop and you have a bunch of hair lying around, and this hair is doing nothing. Bring a flashlight, shine light on this hair, and it starts moving. It's creepy, but it's interesting.

Narrator: Researchers hope to use crystals like this to make tiny machines powered by light that could deliver targeted medicine inside the body. And they’re still exploring what else the dancing crystals can do. The research is being presented at ACS Spring 2024, a meeting of the American Chemical Society.