Modern robots are becoming increasingly significant in security, agriculture, and manufacturing. Researchers are now attempting to imbue these robots with a human-like sense of touch.
California Institute of Technology (Caltech) researchers have developed an artificial skin that gives robots a human-like feeling of touch. Through a single touch, robots can detect temperature, pressure, and even dangerous compounds.
M-Bot is a multimodal robotic sensing platform that combines artificial skin, a robotic arm, and sensors that attach to human skin. The human user can operate the robot with their own movements while receiving input through their own skin thanks to a machine-learning system that connects the two. The platform is designed to provide humans more exact control over robots while simultaneously shielding them from harm.
Robotic fingers are hard, metallic, plasticky, or rubbery, whereas human fingertips are soft, squishy, and fleshy. The printable skin is a viscous hydrogel that makes robot fingers more human-like. The sensors that allow the artificial skin to monitor the world around it are embedded within that hydrogel.
“Inkjet printing has this cartridge that ejects droplets, and those droplets are an ink solution, but they could be a solution that we develop instead of regular ink. We’ve developed a variety of inks of nanomaterials for ourselves. When we want to detect one given compound, we make sure the sensor has a high electrochemical response to that compound. Graphene impregnated with platinum detects the explosive TNT very quickly and selectively. For a virus, we are printing carbon nanotubes, which have a very high surface area and attaching antibodies for the virus to them. This is all mass-producible and scalable.”
Wei Gao, Caltech’s assistant professor of medical engineering
The researchers have combined this skin with an interactive system that allows a human user to manage the robot using their own muscle movements while also receiving feedback from the robot’s skin. The electrodes attached to the forearm of the human operator are positioned to detect electrical signals generated by the operator’s muscles as they move their hand and wrist.
Gao hopes that the system will be used in a variety of fields, including agriculture, security, and environmental protection, allowing robot operators to “feel” how much pesticide is being applied to a field of crops, whether a suspicious backpack left in an airport has traces of explosives, or the location of a pollution source in a river. But first, he wants to make some adjustments.
“I think we have shown a proof of concept,” he says. “But we want to improve the stability of this robotic skin to make it last longer. By optimizing new inks and new materials, we hope this can be used for different kinds of targeted detections. We want to put it on more powerful robots and make them smarter, more intelligent.”