Scientists develop ‘Star Trek phaser’

Its inventors are comparing it to the Star Trek phaser: a way of exploiting an on-off ‘switch’ in nematodes that paralyzes them when they’re exposed to a beam of ultraviolet light.

The animals stay paralyzed even when the light is turned off. But when exposed to ordinary light, they become unparalyzed and wake up. It’s the first time that photoswitching has been demonstrated in a living animal.

The report describes the development and successful testing of a photoswitch composed of the light-sensitive material, dithienylethene. The scientists grew the transparent, pinhead-sized worms – C. elegans – and fed them dithienylethene.

When exposed to ultraviolet light, the worms turned blue and became paralyzed. When exposed to visible light, the dithienylethene became colorless again and the worms’ paralysis ended.

While some of the worms died, many lived through the paralyze-unparalyze cycle.
The scientists aren’t actually sure how the switch causes paralysis. But the study demonstrates that photoswitches may have great potential in turning photodynamic therapy on and off, and for other applications in medicine and research, they say.

The study appears in the Journal of the American Chemical Society (JACS).