Fully merging microbe and machine for the first time, scientists have created gold-plated bacteria that can sense humidity.

The breakthrough is the first "cellborg" in what might become an array of devices that could sense dangerous gases or other hazardous substances.

The bioelectronic device swells and contracts in response to how much water vapor is in the air. It’s called a cellborg humidity sensor, and it is at least four times more sensitive than those that are solely electronic. It even works even when its biological parts are long dead.