Smash-proof smartphones could soon become a reality – thanks to the humble mussel.
Unbreakable electronic devices are being inspired by fatigue-resistant sea shells.
They open and shut without damage for hundreds of thousands of cycles during a bivalve’s lifetime.
An artificial prototype has already been developed with the fatigue-resistant substance also possible for use in aerospace and tissue engineering technologies.
Lead author Professor Yu Shuhong, of the University of Science and Technology of China, explained: “The answer lies in a combination of design and materials that resist brittle fracture over time.”
Mollusk shells are made up of about 95 percent chalk, which is very brittle in its pure form.
But nacre, which coats the inner shells, is made up of microscopic tablets that are a bit like miniature Lego building blocks, making it extremely strong and tough.
It’s highly pliable, allowing the shell to resist impacts without fracturing.
Shuhong said: “Recently, flexible and foldable devices have developed at a dramatic rate.
“More and more foldable devices appear in people’s lives. Long-term service requires the folded parts to endure repeated deformation which might cause fatigue damage to the devices.
“Consequently, the damage will affect the normal function of the devices.”
Microscopic observations showed the hinge gets its unique properties through a structure that resembles a folding fan.
Organic and inorganic matter combine to make a tough mineral called aragonite that makes up the ribs – and a softer matrix.
Hard nanowires of aragonite provide rigidity and help distribute stresses toward the circumference of the hinge.
They are strengthened by twinning planes that develop in crystals.
Shuhong said: “The soft matrix absorbs compressive and shear stresses as the valve opens and closes.
“The folding fan-shaped region in the hinge can sustain large deformation during repetitive opening-and-closing valve motions and maintain its structure and function for a long period.
“The tissue still functions well and shows no signs of fatigue behaviors even after 1,500,000 cycles.”
Mussels, oysters, clams and scallops build an external shell comprising two domed valves that are joined by a hinge.
The valves open for feeding and reproduction and close when the animal is threatened.
Using muscles inside the shell, a bivalve can pull the valves together, safely enclosing the organism’s body.
Bivalves open and close their valves repeatedly throughout the day and, in some species, can live hundreds of years, so fatigue is a potential danger.
A proof-of-concept artificial version with embedded glass fibers in a polymer matrix is described in the journal Science.
Produced in association with SWNS Talker
Edited by Asad Ali and Saba Fatima