Robots of the future could be wrapped in lifelike skin that can repair itself, similar to human skin healing. This groundbreaking advancement utilizes cultured skin cells, creating a new kind of artificial skin that not only appears more realistic but also has the ability to mend cuts and scrapes independently. Researchers published their findings in the journal, highlighting the potential for robots to interact with humans more seamlessly.
Artificial skin has long been considered a way to make robots more human-like, and cultured skin offers a more realistic alternative to synthetic materials like latex. However, a major obstacle has been the tendency for artificial skin to sag off a robot’s frame, creating an undesirable visual effect. To address this, researchers have previously tried attaching the skin with pins, preventing it from shifting but resulting in visible lumps under the skin, compromising its human-like appearance.
In this new study, researchers have devised a revolutionary method. The robot’s skeleton incorporates tiny holes that allow the artificially grown skin to extend v-shaped hooks, aptly named “perforation-type anchors.” These anchors secure the artificial skin to the robot while maintaining a smooth and flexible surface. The artificial skin is then layered on a robot treated with water-vapor plasma to make it hydrophilic, meaning liquids are attracted to the surface. This allows the cultured skin’s gel to be drawn deeper into the holes, clinging more tightly to the robot’s surface.
One of the primary benefits of this self-healing skin is its potential to enable robots to work alongside humans without experiencing excessive wear and tear. Small tears or minor damage can be repaired without manual intervention, eliminating the need for constant maintenance. While the researchers have not yet quantified the healing time, their demonstration of recreating the way human skin changes when smiling showcases the potential of this technology.
In this demonstration, the artificial skin was connected to a robotic face with a sliding layer of silicone underneath. This simulates the “inflating cheeks” effect that occurs when facial muscles contract, causing the skin to push up at the corners of the mouth. The perforation anchors ensure a seamless fit with the 3D mold of a face, eliminating the need for protruding bolts or hooks.
To further validate their approach, the researchers compared the artificial skin applied to surfaces with and without the perforation-based anchors. On surfaces lacking anchors, the skin shrank by a significant 84.5% over seven days, compared to only 33.6% on surfaces with 0.04-inch (1 millimeter) anchors. This shrinkage could detach the skin from the robot’s internal frame, ruining its lifelike appearance and potentially damaging the skin layer. Surfaces with larger 0.1-inch (3 mm) and 0.2-inch (5 mm) anchors showed even longer-lasting results, with shrinkage rates of 26.4% and 32.2%, respectively.
Shoji Takeuchi, a researcher at the University of Tokyo, acknowledges that further development is necessary before robots can be equipped with this groundbreaking skin. He emphasizes the need to enhance the durability and longevity of the cultured skin, addressing concerns about nutrient and moisture supply. This could involve incorporating integrated blood vessels or perfusion systems within the skin. Additionally, improving the mechanical strength of the skin to match natural human skin is crucial, requiring optimization of the collagen structure and concentration within the cultured skin.
Takeuchi also highlights the need for future artificial skin to convey sensory information like temperature and touch to the robot, as well as being resistant to biological contamination. The researchers believe that this research could advance our understanding of how facial muscles convey emotions, potentially leading to breakthroughs in treating facial paralysis, expanding the capabilities of cosmetics and orthopedic surgery. A better understanding of skin adhesion could even eliminate the need for v-shaped holes in future robotic frames.
