You accidentally drop your phone face-down on the pavement. Heart pounding, you pick it up, bracing for the dreaded spiderweb cracks on your screen. But instead of shattered glass, the cracks seem to fade overnight, as if your phone has a mind of its own — quietly repairing itself while you sleep.
Sounds like science fiction? Not anymore. Researchers have been working on materials that can “heal” themselves just like human skin — and your next phone screen might be one of them.
Shattered phone screens are an everyday tragedy. In 2023 alone, 78 million Americans damaged their smartphones, and screen repairs cost a staggering $8.3 billion that year (up from $3.4 billion in 2018).
Globally, countless devices meet similar fates – dropped on sidewalks or knocked off tables – leaving users with pricey repairs or cut fingers. We’ve all seen the telltale spiderweb pattern on a phone; it’s practically a modern icon of frustration. What if our gadgets could fix these cracks on their own, much like a cut on your skin heals with time?
That tantalizing question isn’t just wishful thinking. Self-healing materials – substances that can repair themselves after damage – are on the rise. Your phone screen that mends itself overnight is just one possibility.
The quest to create such materials has been underway for decades, driven by a simple observation: if nature can heal, why can’t our tech? Researchers around the world, from Illinois to Tokyo, have been working to end the era of fragile gadgets and infrastructure by empowering materials with the ability to “heal thyself.”
From Broken Wings to Bio-Inspired Breakthroughs
The story of self-healing materials begins not with phones, but with airplanes and a visionary engineer’s “Eureka!” moment. In the late 1990s, Scott R. White, an aerospace engineer at the University of Illinois Urbana-Champaign, pondered a big problem: tiny cracks hidden inside airplane wings and other critical structures.
These microcracks can grow and cause catastrophic failures, yet they’re hard to detect in time. White and his colleagues at UIUC’s Beckman Institute asked themselves – what if the aircraft could heal its own cracks, the way a bone mends after a fracture?
This question kicked off a scientific detective story, with White’s team drawing inspiration from biology to create materials with lifelike resilience.
In 2001, White’s interdisciplinary team (which included chemist Jeffrey Moore and materials scientist Nancy Sottos) unveiled a revolutionary self-healing plastic in the journal Nature.
Their approach was elegantly simple. They embedded tiny microcapsules throughout an epoxy material, each capsule filled with a liquid healing agent. When the material cracked, the crack would rupture some microcapsules, and like blood oozing from a cut, the liquid would flow into the crack and harden into a glue, sealing the break.
In the lab, a healed sample could regain up to 75% of its original strength.
It was as if the plastic had its own built-in first aid kit. “If microcracks are healed before they grow into larger fissures, structures can have longer lifetimes with less maintenance,” one materials scientist noted, adding that “having a built-in system to slow crack growth makes great sense.”
In other words, this plastic could take a licking and keep on ticking, dramatically extending the lifespan of whatever it was part of.
Researchers dubbed this approach “autonomic healing,” because the material heals autonomously, without any external intervention – much like your body’s automatic response to injury.
The microcapsule concept was a breakthrough that sparked worldwide excitement. Suddenly, the dream of self-healing phone screens, cars, bridges – even spacesuits – felt a lot more plausible. And the Illinois team didn’t stop there. They had essentially given materials a one-shot healing ability.
The next challenge: could materials heal themselves multiple times, not just once?
“Vascular” Materials: Giving Polymers a Circulatory System
In nature, healing is rarely a one-and-done event. Our bodies have blood vessels that continuously deliver repair cells and nutrients to wounds. Inspired by this, White, Sottos, and Moore pushed the concept further.
By 2014, their group at the Beckman Institute’s Autonomous Materials Systems lab had developed microvascular networks within composites – tiny, vein-like channels that carry liquid healants. They engineered a mesh of two separate micro-channel networks (imagine a 3D grid of microscopic tubes) inside a fiber-reinforced epoxy, each network containing one part of a two-component restorative resin
When a crack cut through the material, it also cut through these micro-vessels, allowing the liquids to gush out, mix, and polymerize (harden) right in the crack, “akin to a bleeding cut,” as lead author Jason Patrick described
In this system, materials could heal over and over – the researchers repeatedly cracked their test composites and watched them repair themselves nearly good as new each time, with almost 100% healing efficiency.
Bottom: A simpler parallel channel design results in less mixing (distinct red and green), and thus less effective healing. These vasculature-inspired designs let critical components heal repeatedly, much like blood vessels help wounds clot in organisms.
“This is the first demonstration of repeated healing in a fiber-reinforced composite system.”
Professor Scott White.
He noted that earlier self-healing tricks worked in simple plastics but not in tough fiber composites
The missing link was giving the material a circulation system, just as flesh and bone have. With that in place, the composite could heal again and again without manual repair
It was a cinematic moment for materials science: after years of incremental progress, the team had created something reminiscent of sci-fi – a material that just won’t stay broken. This advance was more than a cool lab demo; it hinted at huge real-world stakes.
Think of airplane wings or spacecraft structures that could survive damage that would normally be fatal, by instantly self-sealing cracks before they spread. The audience of engineers and scientists was in awe – and eager to run with these ideas.
Smartphones That Heal Themselves
While aerospace engineers were dreaming of self-repairing wings, another group of researchers (and, frankly, all of us clumsy phone owners) had a more down-to-earth dream: a phone screen that heals from scratches and cracks overnight. Believe it or not, the groundwork for such technology is already here. Back in 2013, LG released the G Flex smartphone, which featured a special self-healing coating on its back cover.
It wasn’t perfect – deep key scratches were more than it could handle – but minor scuffs from daily use would magically fade away in minutes or hours. The secret was a polymer layer that could flow at the scratch site and re-bind, “growing back into a scratch” to erase it
In fact, Nissan had earlier developed a similar self-healing paint for its cars, a gel-like coating that could fix fine scratches on a car’s surface. In small cases, the healing happened in as little as an hour, whereas bigger dings took about a week – “not unlike human skin,” as one Nissan manager quipped
This paint was even used on a prototype smartphone case, hinting that consumer electronics could borrow automotive tech to stay shiny and new.
The holy grail, however, is a self-healing display – not just the backside or paint, but the actual glass you look at and touch. Glass is hard and brittle, which makes it tough to self-repair. For a long time, self-healing materials were either soft rubbers or required some heat to seal a crack.
That changed in 2017 when a breakthrough came from an unexpected place. At the University of Tokyo, graduate student Yu Yanagisawa was working on a new polymer intended to be a glue.
In a happy accident (the kind that science serendipity is famous for), he found that this material – a lightweight polymer called polyether-thiourea – could bond back together after being broken, just by pressing the pieces together at room temperature.
Two fractured edges of this polymer glass would fuse in seconds with firm pressure, and within a couple of hours the material would regain its original strength.
The team, led by Professor Takuzo Aida, realized they had a self-healing glass. They published the discovery in Science, declaring it the first hard glass-like substance that can repair itself without any heating.
As Aida’s team noted, usually you’d have to re-melt or heat damaged glass to high temperatures (over 120 °C) to fix it, which isn’t practical in a phone.
But this new material bucks that trend – it heals at room temp, making it a prime candidate for future phone screens and other gadgets.
The implications were immediately clear. “End of the smashed phone screen?” one headline mused.
A screen material that self-mends could make our devices far more sustainable – fewer thrown-away phones and tablets, less electronic waste, and cost savings for users. It’s not on your iPhone or Samsung just yet, but companies are racing to bring it to market.
Apple has even filed patents for a foldable phone that heals its own screen. In one patent, Apple describes a display with a self-healing elastomer layer that can repair dents and scratches automatically — for example, while the phone is charging overnight using heat, light, or electrical current to catalyze the fix
The idea is that a foldable device’s screen could self-correct minor wear and tear so that the fragile fold doesn’t turn into a permanent crease or crack. Analysts predict that by 2028 we’ll see the first phones with self-healing displays hitting the market
In other words, the next generation of phones might actually recover from the abuses of daily life. Dropping your phone at 11 PM and waking up to an intact screen could realistically happen in a few years – a relief for anyone who’s ever squinted through a shattered display (which is to say, nearly everyone).
Living Concrete: Buildings That Heal Their Own Cracks
It’s not just plastics and electronics – even heavy, stodgy materials like concrete are getting a self-healing makeover. If you’ve ever noticed weeds growing through cracks in a sidewalk, you know how even the smallest fissure can expand and weaken concrete over time.
For bridges, tunnels, and buildings, cracks are the enemy within – water seeps in, steel rebar rusts, and a tiny crack can turn into a safety hazard requiring costly repairs. Enter Dr. Henk Jonkers, a microbiologist at Delft University of Technology in the Netherlands, who took an unconventional approach: he brought living bacteria into the mix.
Jonkers started working on bio-concrete in 2006, asking what kind of bacteria could survive dormant in dry concrete until needed. After testing many microbes, he found a genus of hardy soil bacteria (Bacillus) that thrive in the high-alkaline, stone-like environment of concrete.
These bacteria can lie inactive for years, forming spores (like plant seeds) that awaken only when water seeps into a crack. Jonkers also mixed in a nutrient (calcium lactate) to feed the bacteria when they revive.
The result: when a crack forms and water begins to enter, the bacteria wake up and munch on their food, producing limestone as a byproduct – the same mineral that makes up natural concrete.
That limestone precipitates into the crack, effectively filling it and patching the structure before the crack grows. In essence, the concrete heals itself with a little help from its bacterial friends.
“It is combining nature with construction materials. Nature is supplying us a lot of functionality for free. In this case, limestone-producing bacteria.”
Dr. Henk Jonkers explained.
By 2010, Jonkers successfully proven self-healing concrete in the lab, and by 2015 his team was testing it in real structures. The promise is huge: imagine bridges that last decades longer because they fix tiny cracks on their own, or concrete walls that automatically seal after an earthquake causes micro-fractures.
Some engineers are also exploring chemical capsules (like the microcapsules in plastic) for concrete – for instance, tiny beads of sodium silicate that burst open to seal cracks
Others have even tried embedding fungus into concrete as a healing agent. It’s a wild, cross-disciplinary effort: biologists, chemists, and civil engineers working together to create construction materials that behave more like living tissue than inert rock.
If successful, self-healing concrete could reduce the monumental costs of infrastructure maintenance and make our structures safer. No more hairline cracks turning into gaping potholes on your highway – the road could heal itself after each winter freeze.
The environmental payoff is significant too. Concrete production is a major source of CO₂ emissions worldwide (cement, the key ingredient, is very carbon-intensive to produce). If buildings and roads last longer, we don’t need to rebuild or repair them as often, which means a lower carbon footprint in the long run.
A world with self-healing concrete is a world with more durable bridges and tunnels – and fewer construction crews jackhammering away old, damaged concrete slabs. It’s like giving our cities a bit of a biological upgrade, borrowing resilience from Mother Nature to make infrastructure that stands the test of time.
Planes, Cars, and Spacecraft: No More Cracks in the Sky
Coming back to where this all started – aerospace – self-healing materials could be a game-changer for safety and maintenance. Modern aircraft and spacecraft are built with advanced composites (lighter than metal, but can be brittle).
A tiny crack deep inside a composite wing or spacecraft habitat is the stuff of engineers’ nightmares. With self-healing composites, as pioneered by White and colleagues, we might one day have airplanes that “bleed” resin to heal small cracks in flight, ensuring they never become big cracks.
“The beauty of this self-healing approach is, we don’t have to probe the structure and say, this is where the damage occurred and then repair it ourselves. When a fracture occurs, this ruptures the separate networks of healing agents, automatically releasing them into the crack plane—akin to a bleeding cut. As they come into contact with one another in situ, or within the material, they polymerize to essentially form a structural glue in the damage zone. We tested this over multiple cycles and all cracks healed successfully at nearly 100 percent efficiency.”
Jason Patrick, a Ph.D. candidate in civil engineering and lead author.
In fact, researchers have already demonstrated self-sealing fuel tanks and membranes: if a puncture occurs, a gel or resin automatically plugs the hole, preventing leakage. The military and NASA have been keenly interested in such technology – it could make spacecraft more robust against micrometeorite punctures, or help drone aircraft survive damage that would otherwise down them.
In the automotive world, we’ve seen how Nissan used self-healing paint to keep cars looking new. But future cars might go further: envision autonomous vehicles that self-repair minor body damage after a fender-bender, or even engine parts that adjust and heal to prevent wear.
These concepts are in early stages, but not outlandish given current progress. Engineers have experimented with self-healing tires (using elastic polymers to re-seal punctures) and self-healing brake cables for bicycles.
The goal is to make our transportation not only smarter but also tougher and more forgiving. If your car can fix its own minor dings, that’s fewer trips to the body shop and a longer service life.
Even the concrete in tunnels and runways used by transportation can benefit (tying back to bio-concrete). Airplane runways with self-healing concrete could reduce downtime from repairs. And let’s not forget emerging tech like drones and flying taxis. They rely on lightweight materials that could use self-healing to recover from bird strikes or weather damage.
These applications capture the imagination because they edge toward something mythical: machines that repair themselves. It brings to mind scenes from The Terminator (the shape-shifting T-1000 robot reassembling itself) or the self-healing armor of comic book heroes.
We’re not at that level of complexity yet, but the building blocks are here. Every successful lab experiment – a healed airplane wing panel, a re-sealed car scratch – adds confidence that “no-maintenance” vehicles might be a reality in the future.
Electronic Skin and Unbreakable Circuits
Perhaps one of the most awe-inspiring developments is in the realm of electronics and prosthetics. Consider the marvel of human skin: it’s soft, flexible, full of sensors, and it heals when cut. Engineers have long dreamed of giving prosthetic limbs or robots a “skin” with similar qualities.
In 2012, Stanford University chemical engineer Zhenan Bao and her team made a big leap toward that dream. They created a flexible, transparent electronic skin material that is not only touch-sensitive (it can detect pressure) but also self-healing at room temperature – and it can do this repeatedly.
“To interface this kind of material with the digital world, ideally you want them to be conductive.”
Benjamin Chee-Keong Tee, first author of the paper.
The material is essentially a flexible plastic polymer laced with tiny particles that give it electrical conductivity. When you cut this synthetic skin and press it back together, within seconds it begins to bond, and in a few minutes the cut disappears to the naked eye.
More impressively, its electrical properties also restored, which means if it was part of a circuit, the circuit closes up again as if nothing happened.
“The advance could lead to smarter prosthetics or more resilient personal electronics that repair themselves.”
The Stanford team noted.
In other words, your future smartwatch might not crack under stress – and if it does, it could heal and keep on working.
The secret behind many of these self-healing electronics is special chemistry at the molecular level. Bao’s team, for example, used dynamic covalent bonds – bonds that break and re-form – within their plastic. It’s a bit like a zipper that can come apart and then zip itself back up.
Other researchers have used supramolecular chemistry (networks of molecules that naturally stick together like Velcro) to make electronics that heal with a little heat or pressure. One team even made a self-healing transistor – the building block of circuits – using a polymer that could restore its structure and function after being cut.
And in 2021, scientists demonstrated soft robotic hands that, after being gashed, could heal and continue working – an important step if we want robots to operate in harsh, unpredictable environments.
All these advances evoke a sense of awe: we are essentially teaching lifeless circuits and plastics to behave like living tissue. The practical benefits are easy to see. For wearable electronics like health monitors or smart clothing, self-healing means longer life and fewer failures. For medical implants, it could mean safer, more reliable devices.
And for the general consumer, it promises gadgets that you don’t have to baby with cases and screen protectors – they’ll be able to take care of themselves to some extent.
Why Self-Healing Materials Matter for Our Future
Beyond the cool factor and clever lab demos, self-healing materials carry significant practical value. They address some of the nagging problems of modern technology and infrastructure in a fundamentally new way – by preventing damage from becoming a failure. Here are some of the broader implications of this emerging class of materials:
- Longer-Lasting Products and Infrastructure: From phones that don’t need screen repairs to concrete bridges that won’t require frequent patching, self-healing materials promise dramatically longer lifespans. This means cost savings for consumers (fewer repair bills, less frequent device upgrades) and for society (longer intervals between rebuilding roads, buildings, and airplanes).
- Enhanced Safety: If an airplane wing or a car chassis can mend small cracks in real-time, the risk of catastrophic failure drops. Structures that heal themselves can avoid collapse or accidents, giving an extra margin of safety. Similarly, self-healing coatings on electrical components could prevent short circuits by repairing insulating layers, and reducing fire hazards.
- Environmental Sustainability: We live in a throwaway culture with mounting electronic waste and resource consumption. Self-healing materials could make our devices and structures so durable that we use fewer raw materials over time. For example, if your smartphone lasts 5-6 years instead of 2-3 because it self-repairs wear and tear, that’s one less phone that needs to be manufactured (and one less in the landfill). In construction, more durable self-healing concrete and steel mean less frequent rebuilding, translating to lower carbon emissions from cement production and construction machinery. It’s a virtuous cycle of using ingenuity to reduce waste.
- Reduced Maintenance and Monitoring: Today, we spend enormous effort on inspections – checking aircraft for hairline cracks, surveying bridges for damage, and sending robots to Mars with redundant systems in case something breaks. With materials that fix themselves, maintenance could become less hands-on. This doesn’t mean we stop inspections altogether, but problems might fix themselves before we even notice them. That frees up humans to focus on bigger issues and lowers the life-cycle cost of everything from cars to wind turbines. A wind turbine blade that heals microcracks from stress could prevent the kind of breakdown that requires a costly replacement high up on a mast.
- Bio-Inspired Design Philosophy: On a more philosophical note, the rise of self-healing materials signals a shift in how we design technology. We’re increasingly looking to nature’s playbook – emulating the resilience of living systems. This approach can lead to other innovations, like self-regulating materials (that adapt to temperature), or self-assembling materials. It’s part of a broader movement of biomimicry in engineering, which often yields solutions that are efficient and sustainable. Self-healing is one of the most vivid examples of biomimicry: we’ve essentially taught polymers how to behave like immune systems, patching up damage and stopping the spread of “injury.”
A Future Where Technology Can Heal Itself?
As we stand today, self-healing materials are transitioning from the lab to the real world. The first wave of products – scratch-healing paints, self-healing phone cases, experimental concrete – have proven the concept. The next wave in the coming decade could see self-healing features as a selling point in consumer tech (“never worry about cracked screens again!”), in construction materials for smart cities, and in the vehicles that move us around.
We are on the cusp of a materials science revolution that carries a certain poetry with it: our creations are starting to mimic the lifelike ability to recover and endure.
This convergence of biology and technology raises some thought-provoking questions. If our phones, cars, and buildings can heal themselves, are they inching closer to qualities we only associate with living organisms?
At what point does a machine that constantly regenerates essentially become a form of artificial life? These are questions that scientists and philosophers alike may ponder as the line between the living and non-living blurs.
One thing is certain: self-healing materials evoke a sense of wonder. They remind us that even the most everyday objects – a phone screen, a concrete wall – need not be inert and helpless against damage. With ingenuity, we’ve made them responsive, almost alive in their behavior. The next time you see a cracked screen or a pothole, consider this: in the near future, that crack might just heal on its own.
Our materials are learning the art of resilience, and as they do, we step closer to a world where technology lives harmoniously with nature’s principles. In the end, self-healing materials prompt us to ask not just “How does it work?” but also “What else can we make materials do, when we infuse them with life-like intelligence?” The answers will shape the very fabric of the future – perhaps one day, a future where broken things fix themselves while we sleep, and the phrase “replace it” gives way to “wait, it will heal.”
