Laser light turns graphene paper into a microbot

FOLDING UP A plus sign–shaped piece of graphene paper can fold into a box when researchers hit it with light.

Donghua University

November 6, 2015 at 3:00 pm

Blasts of laser light can make a microbot hustle.

A rectangle of graphene paper about the size of a fingernail can walk, fold and even turn corners, researchers report November 6 in Science Advances.

Materials scientist Jiuke Mu and colleagues from Donghua University in Shanghai designed the paper with a graphene-and-polymer material that sucks water from the environment. Swollen with water, the paper laid flat like a scrap of pressed tinfoil. But when the team hit the paper with light, water frizzled away, making the material shrink and forcing the paper to fold together. Blinking laser light on and off made the paper fold and then flatten again, letting the bot inch along like a tiny worm.

The origami-inspired material could one day make up artificial muscles or find use in robotics, the authors suggest.

LIGHT ACTIVATED Switching on and off a laser light forces a scrap of graphene paper to “walk.” Shining light on the paper makes it fold; turning off the light lets the paper relax. Donghua University