Robot arm learns how to taste with engineered bacteria

Posted Jul 6, 2019 by Tim Sandle
Biologists working with engineers have developed a robotic gripping arm which makes use of engineered bacteria in order to 'taste' for certain chemicals. This represents a new development in soft robotics.
File photo: Digit is a two-legged robot designed and built by Agility Robotics to not only approxima...
File photo: Digit is a two-legged robot designed and built by Agility Robotics to not only approximate the look of a human, but to walk like one, too.
Ford Motors, Media
The robotic gripper is a little way off from being put into use (the new research stands as a proof-of-concept study, having been constructed at University of California - Davis). The two main elements of the robot are a flexible light-emitting diode circuit which is necessary for converting biological to electronic signals, and soft pneu-net actuators which convert the electronic signals to movement of the gripper.
The biological signals come from a specially designed biosensing module based on Escherichia coli bacteria. The microbes used have been genetically engineered to respond to the chemical IPTG. The response leads to the organisms producing a fluorescent protein.
With the operation, the bacteria are located within wells. Each well is fashioned with a flexible, porous membrane, which permits chemicals to enter but keeps the organisms inside. This biosensing module is slotted into the structure of the flexible gripper fitted onto a robotic arm.
This means when it is dipped into a chemical, the gripper senses or “tastes” the environment. In tests the robot arm has been shown to be effective with differentiating between different levels of chemical concentrations.
Commenting on the development, Professor Cheemeng Tan, who was involved with the research, says: “"Our long-term vision is about building a synthetic microbiota for soft robots that can help with repair, energy generation or biosensing of the environment.”
In trials the biohybrid gripper made use of chemical sensing and feedback in order to enact decisions during a pick-and-place operation. This study should open up new opportunities in soft materials, synthetic biology, and integrated interfacial robotic systems.
The following video shows the prototype in action:
The new development represents an advancement in biologically-based soft robotics. The research has been published in the journal Science Robotics, with the study titled “A biosensing soft robot: Autonomous parsing of chemical signals through integrated organic and inorganic interfaces.”