Self-healing aircraft wings fix themselves after damage

Scientists have invented aircraft wings that fix themselves after damage

Self-healing technology is one step closer after scientists produce aircraft wings which fix themselves. Even the researchers involved in the project describe it as “verging on science fiction”. A team of British scientists has produced aircraft wings that can fix themselves after being damaged, suggesting that self-healing technology will soon become commonplace.

Their research which was due to be presented at a Royal Society meeting in London this week, is being billed as a crucial step in an emerging field which could soon produce self-healing nail polish and a cure for cracked mobile phone screens.

A team at the University of Bristol is developing the technology for the past three years. Professor Duncan Wass confirmed that the self-healing products will reach consumers in the “very near future”. His team specialises in modifying carbon fibre composite materials, the strong but lightweight substances used increasingly widely in the manufacture of everything from commercial aircraft wings to sports racquets and high-performance bicycles. They have been working with aerospace engineers at the university to know if there was a way of preventing the tiny, almost undetectable cracks that form in an aircraft’s wings and fuselage.

The team’s ingenious solution started “on the back of an envelope” but has since developed into useable technology. It involves adding tiny, hollow “microspheres” to the carbon material so small that they look like a powder to the human eye which break on impact, releasing a liquid healing agent. The agent seeps into the cracks left by the damage before coming into contact with a catalyst, triggering a rapid chemical reaction which causes it to harden.

Professor Wass commented “We took inspiration from the human body and have not evolved to result any damage. He also said that if we were like that we’d have a skin as thick as a rhinoceros but if we do get damaged, we bleed, and it scabs and heals. Also stated that they have just put the same sort of function into a synthetic material: let’s have something that can heal itself.”

Laboratory tests research concluded that the material is just as strong after it has “healed”, raising the possibility of aircraft wings that can repair themselves “literally on the fly” if a bird strike takes place in mid-flight, Professor Wass said.

This advanced technology could also make airline safety checks cheaper as a dye could be added to the healing agent resulting any damage to an aircraft to stand out like a bruise. Due to this technology, engineers would identify the damaged areas very quickly and will make sure that they do not miss anything as they examine the plane. Professor Wass said a bruise was a “good analogy” but accepted that the dye would need to be tweaked to cater for nervous pilots. “We’d probably do it with something which is invisible to the naked eye that you’d need to put an ultraviolet light on, as you don’t want an aeroplane wing with a big red splodge on it showing that it’s been damaged.”

The material can take a couple of hours or a day to recover according to the outside temperature. “If you’re on a runway in Dubai it would probably take couple of hours to heal, on the other hand, if you were on a runway in Reykjavik during winter season it would probably take more than 24 hours,” Professor Wass said.

The research was made by the Engineering and Physical Sciences Research Council’s UK Catalysis Hub, a collaborative project between universities and industry. This week’s conference will be held to entitle Catalysis Improving Society and will be one of the first events at which the team’s achievements will be announced in public.

Professor Richard Catlow of the University of London, who organised the meeting, said the research showed that catalysis which is already used widely in the petrochemicals industry that could offer huge benefits in other areas, at a “relatively low cost”.

The Bristol team’s advances could be applied to all kinds of carbon fibre composite materials which meant that self-healing golf clubs, tennis racquets, fishing rods and bike helmets could be just around the corner.

The largest cosmetics firm L’Oréal has also contacted the team to register its interest in self-healing nail varnish. This would require different technology, but Professor Wass stated that the general principle would remain the same. Professor Wass is confident that in the next decade we’ll see mobile phones with displays that can fix themselves after developing cracks.

Self-healing technology was first time discovered in the year 2001, when researchers at the University of Illinois in the US created a plastic capable of repairing itself when it cracked. Last year, the same team invented a polymer, inspired by the human blood-clotting system, which patched holes up to 3cm wide.

Professor Wass’s team at the University of Bristol has been focusing on the creation of self-healing versions of carbon fibre composite materials, which are extensively used in the aerospace industry but also have many other applications. The BMW i8 electric sports car has a carbon fibre passenger compartment to make up for the weight of its heavy battery. The material is very attractive to car manufacturers as it is 30 per cent lighter than aluminium and self-healing technology would make it safer too. The Airbus A380 passenger jet has a carbon fibre reinforced plastic fuselage for a lower fuel consumption. The researchers also claim that the new technology would help wings to fix themselves in mid-flight, and allow engineers to spot cracks more easily.

Researchers say that the carbon fibre composite developed by them has the same principle and it can repair the damaged part ‘on the fly’ if a bird hits the plane in the air. The carbon composite blades are 100 feet in the air, so maintaining them is notoriously expensive and difficult. Carbon fibre bicycle frames are very popular with cyclists as they are so light, but they are also liable to crack. If they could self heal, their durability could be massively increased and the technology could also be applied to crash helmets.

The team believes that their material can have wide range of applications – from helmets to fishing rods and golf sticks.