Recently, scientists from the Max Planck Institute for Intelligent Systems in Germany and the University of Pennsylvania in the United States jointly developed a biosynthetic protein material that successfully addresses the current limitations of self-healing soft materials by enhancing the healing properties of series repeat peptides. The study is expected to be a major application in the field of soft robotics, with the results published recently in the journal Nature Materials.
Self-healing materials are a type of intelligent material with structural self-healing capabilities. In recent years, synthetic, self-remediation biomaterials have come under increasing attention from scientists, inspired by biological systems that can self-repair after injury.
Currently, scientists are working together to develop a high-strength synthetic protein that can repair micro and macro mechanical damage in a very short period of time, fully restore its structure and properties, and have programmable healing properties. This healing performance provides new opportunities for bio-inspired material design and addresses the limitations of self-healing materials currently used in soft robots and personal protective equipment.
‘We changed the molecular structure of the octopus tentacle protein to maximize the self-healing ability of the material,’ said Professor Demirel of Pennsylvania State University. In nature, self-healing takes a long time, such as 24 hours. Now, we’re reducing the repair process to 1 second.
Dr. Abdon Pena-Francis of the Max Planck Institute for Intelligent Systems, a leading member of the research team, explains that octopuses take longer to heal because the protein molecules in their hands are simply intertwined. In laboratory-developed materials, we have changed the nanostructures of molecules to connect them to each other. These materials are system-optimized to improve their hydrogen bond-binding nanostructure and network morphology, have programmable healing properties (2 to 23MPa strength after 1 second of healing), and the healing speed and strength exceed those of several orders of magnitude in other natural and synthetic soft materials.
Professor Metin Siti of the Max Planck Institute for Intelligent Systems led his team in studying how to use this self-healing soft material in software robots. The researchers designed and built a pneumatic soft actuator and built a soft gripper, a promising application of soft robotics in the food, pharmaceutical, packaging and retail industries. In addition, biosynthetic protein materials provide a promising platform for soft robots to be closer to simulating complex biological systems and provide a wide range of design space for multi-functional soft robots.
After a person’s skin is scratched, the wound will heal automatically after a while. If the materials used to manufacture various products and equipment can also be repaired automatically after wear and tear, wouldn’t it extend their life and ensure their stable performance? As a result, self-healing materials mimic the principle of healing of biological damage. The latest research is inspired by octopus tentacles. Self-healing materials can be achieved either by heating or by dispersing or compounding some functional substances inside the material. The study is more in favor of the latter, and its findings will be useful in the field of smart soft robots.