If you’ve seen Terminator, you’ll have had a hard time forgetting the gruesome self-healing scene – and its sound effects.
Well now, self-healing cyborgs are a giant step closer thanks to a team of Japanese scientists who discovered how to bind engineered skin tissue to humanoid robots.
They say the breakthrough brings with it potential benefits to robotic platforms including increased mobility, embedded sensing capabilities and an increasingly lifelike appearance.
Taking inspiration from human skin ligaments, the team, led by biohybrid robot expert Professor Shoji Takeuchi of the University of Tokyo, included special perforations in a robot face, which helped a layer of skin take hold.
The team say their research, published in the journal Cell Reports Physical Science, could also be useful in the cosmetics industry and to help train plastic surgeons.
So far, Professor Takeuchi’s lab, the Biohybrid Systems Laboratory, has created mini robots that walk using biological muscle tissue, 3D printed lab-grown meat and engineered skin that can heal.
It was during that research Professor Takeuchi felt the need to take the idea of robotic skin further to improve its properties and capabilities.
‘During previous research on a finger-shaped robot covered in engineered skin tissue we grew in our lab, I felt the need for better adhesion between the robotic features and the subcutaneous structure of the skin,’ he said.
‘By mimicking human skin-ligament structures and using specially made V-shaped perforations in solid materials, we found a way to bind skin to complex structures.
‘The natural flexibility of the skin and the strong method of adhesion mean the skin can move with the mechanical components of the robot without tearing or peeling away.’
Previous methods to attach skin tissue to solid surfaces involved methods such as mini anchors or hooks, but these limited the kinds of surfaces that could receive skin coatings and could cause damage during motion.
By carefully engineering small perforations instead, Professor Takeuchi says essentially any shape of surface can have skin applied to it.
In January of this year, Professor Takeuchi and his team revealed they had created a part-human, part-machine robot by combining muscle tissues with artificial materials.
The unnamed two-legged cyborg is made from silicone rubber which bends and flexes to make muscle movements – along with the help of lab-grown skeletal muscle tissues on each leg.
‘Self-healing is a big deal – some chemical-based materials can be made to heal themselves, but they require triggers such as heat, pressure or other signals, and they also do not proliferate like cells,’ said said Professor Takeuchi.
‘Biological skin repairs minor lacerations as ours does, and nerves and other skin organs can be added for use in sensing and so on.’
Professor Takeuchi and his team have a goal in mind for the application that could help in several areas of medical research.
The idea of an organ-on-a-chip is not especially new, and finds use in things such as drug development, but something like a face-on-a-chip could be useful in research into skin ageing, cosmetics, surgical procedures, plastic surgery and more.
Professor Takeuchi says that if sensors can be embedded, robots may be endowed with better environmental awareness and improved interactive capabilities.
‘Through this research, we identified new challenges, such as the necessity for surface wrinkles and a thicker epidermis to achieve a more humanlike appearance,’ he said.
‘We believe that creating a thicker and more realistic skin can be achieved by incorporating sweat glands, sebaceous glands, pores, blood vessels, fat and nerves.
‘Of course, movement is also a crucial factor, not just the material, so another important challenge is creating humanlike expressions by integrating sophisticated actuators, or muscles, inside the robot.
‘Creating robots that can heal themselves, sense their environment more accurately and perform tasks with human-like dexterity is incredibly motivating.’
