Little mighty creature of the ocean inspires strong new material for medical implants and armour

The research is likely to lead to making ceramics -- today's preferred material for medical implants and military body armour -- many times stronger. These findings were published in a recent issue of the journal Science, and focused on the mantis shrimp's ability to shatter aquarium glass and crab shells alike.

The common creature native to the Indo Pacific, has club-like 'arms' which can strike prey at speeds matching that of a 5.56mm rifle bullet. Each impact generates a force exceeding 50 kilograms, which is hundreds of times the mantis shrimp's weight.

Assistant Professor Ali Miserez, from NTU's School of Materials Science Engineering (MSE) and School of Biological Sciences (SBS), collaborated with Dr James Weaver from Harvard University as well as scientists from the University of California-Riverside, Purdue University, and Brookhaven National Laboratory in the United States.

They have observed down to the nanoscale the highly unique composite structure of the mantis shrimp's club and discovered that it is weaved together in a unique fashion to create a structure tougher than many engineered ceramics. This is the first time that the mantis shrimp's club is studied in such detail.

"The highly damage resistant property of the mantis shrimp could be most useful in medical products such as hip and joint implants, as they sustain impacts hundreds of times daily during walking and daily activities," said Asst Prof Miserez, a recipient of the National Research Foundation Fellowship, which provides a research grant of up to S$3 million over five years.

"Damaged hip implants are a real problem, and cost billions of dollars to the healthcare systems worldwide. They also cause painful surgeries to patients when they need to be replaced. Using a nature-inspired blueprint to design biocompatible implants is actually a 'shrimple' solution."

There is also the problem where the present implants can cause bone loss during the wear and tear process. Likewise, fine particles from metal implants have been known to cause toxicity and immune reactions from the patient's body, causing pain and even disability in some cases.

Designing a damage-resistant implant which is made out of a bio-compatible bone material would solve the above problems, as the material exists naturally in the human body. Asst Prof Miserez, whose laboratory is situated at MSE's Centre for Biomimetic Sensor Science, said they will continue their research to better understand the design and materials and will attempt to replicate it in the laboratory next year.

His team, which includes PhD student Shahrouz Amini, will be focusing on developing a new bio-compatible material which could be used for medical implants such as hip implants. However, the potential applications for these nature-inspired designs are widespread because the final product is expected to be lighter weight and more impact resistant than existing products. These could include new types of armour plating, lighter vehicles and tougher engine and aircraft components like pistons and gears, all of which suffer from impact, wear and abrasion damage over time.

Currently, the 36-year-old Swiss professor is working with post-graduate students and plans to have NTU undergraduates participate in this ground-breaking research as well. Asst Prof Miserez, who also teaches undergraduate students, aims to have two undergraduates each year in the NTU team as they continue their research to better understand the design and materials with the aim of replicating it in the laboratory next year.

He plans to recruit eight undergraduates per year into his research team, which specialises in bio-mimicking -- a highly interdisciplinary field.

"I want to inspire young people to take up science research, by giving them a chance to participate in cutting-edge research and using state-of-the-art equipment, just like how I was inspired by my professors when I was a student," said Asst Prof Miserez.

"I hope more students will be attracted to stay in Singapore for their degrees because we have shown that at NTU, we are doing innovative research on par with the rest of the world. The mantis shrimp is a compelling example of our work, and we currently have many more exciting projects related to bio-inspired engineering in the lab."