By embedding engineered bacteria into the fingers of a robot arm, researchers have created a biohybrid bot that can "taste" -- and they think it could lead to a future in which robots are better equipped to respond to the world around them. For their study, which was published in the journal Science Robotics on Wednesday, a team from the University of California, Davis, and Carnegie Mellon University engineered E. coli bacteria to produce a fluorescent protein when it encountered the chemical IPTG. They then placed the engineered bacteria into wells built into a robot arm's flexible grippers. Finally, they covered the wells with a porous membrane that would keep the bacteria in place while letting liquids reach the cells. To test the system, the researchers had the arm reach into a water bath that sometimes contained IPTG. If the chemical was present, the bacteria would glow, and this light would trigger electronic circuits to send a signal to the gripper's control unit, letting it know not to place an item in the bath.