"Hundreds of subways riders and stadium spectators may one day owe their lives to the death of a single cell," Erik Baard writes in today's Wired News.

Engineers at the University of California at Berkeley have merged a living cell with an electrical circuit so that in a chemical attack the cell's death would trip an alarm.

The bionic chip, made by Boris Rubinsky and Yong Huang, updates the 19th-century coal miners' trick of bringing canaries down into shafts. When the delicate birds died from inhaling poisonous gases, the workers knew to evacuate.

The Berkeley bionic chip works by gauging the electrical resistance of a cell membrane. In the cell's death throes, that resistance spikes, and then plummets.

"Most current security systems work by detecting specific pathogens and toxins, so if an attacker uses a more exotic agent, it could slip by unnoticed," Rubinsky wrote in an e-mail. "Our system will detect anything that has the ability to kill a cell -- even when not expected."