Engineers at the University of British Columbia have collaborated with the Japanese automotive company Honda to develop an e-skin for robotic prostheses. This e-skin allows robotic hands to sense their environment in significant detail, enabling them to perform tasks that require a significant degree of dexterity and tactile feedback, such as grasping an egg or lifting a glass of water without breaking it. The elastomer skin contains fixed and sliding pillars that allow it to buckle and wrinkle, much like real skin. The skin contains four deformable capacitators that allow it to distinguish between normal and shear forces, enabling fine control of its interaction with grasped objects. The researchers hope that the technology will enhance robotic prostheses and enable users to expand the range of daily activities they can perform using their prosthetic devices.
Robotic prostheses are evolving, and the development of skin-like sensors is essential for their continued advancement. These sensors are crucial for enabling robotic hands to perform tasks with precision, such as grasping delicate objects without causing damage. Skin-like sensors have been advancing rapidly in recent years, offering new capabilities for robots and robotic prostheses to sense their environment more comprehensively.
The e-skin developed by the researchers is highly sensitive, expanding the types of activities that are possible. According to Mirza Saquib Sarwar, a researcher involved in the study, “Our sensor can sense several types of forces, allowing a prosthetic or robotic arm to respond to tactile stimuli with dexterity and precision. For instance, the arm can hold fragile objects like an egg or a glass of water without crushing or dropping them.”
Aside from robotic prostheses, the technology may also find applications in medical or assistive robots, such as those used for caring for the elderly, or even surgical robots that interact with soft tissues inside the body. John Madden, another researcher involved in the study, explained, “Our sensor uses weak electric fields to sense objects, even at a distance, much like touchscreens do. But unlike touchscreens, this sensor is supple and can detect forces into and along its surface. This unique combination is key to adoption of the technology for robots that are in contact with people.”
The researchers emphasize that while the e-skin is easy to fabricate at scale and can cover significant areas, further advancements are needed in the future. Madden pointed out that “Human skin has a hundred times more sensing points on a fingertip than our technology does, making it easier to light a match or sew. As sensors continue to evolve to be more skin-like, and can also detect temperature and even damage, there is a need for robots to be smarter about which sensors to pay attention to and how to respond. Developments in sensors and artificial intelligence will need to go hand in hand.”
The study has been published in the journal Scientific Reports, under the title “Touch, press and stroke: a soft capacitive sensor skin.”
Source: University of British Columbia
