When Huawei and Samsung served up their first out-of-the-box foldable devices to the world in 2019, once tech enthusiasts lifted their jaws off the ground, the first question on many people’s lips was, “How are they fragile?
Despite being some of the most expensive and technologically advanced phones on the market, these glass cannons are much more likely to break than your average “candy bar” handset.
Just look at the original Samsung Galaxy Fold – the company had to go back to the drawing board after only about a day of releasing the device in the wild; with reports of a problematic hinge that let grain sneak under the screen causing instant irreparable damage, alongside a pre-installed protector that started to come off on its own, shutting down likewise way the screen in its tracks.
While manufacturers are well aware of the problems faced by conventional smartphones, creating foldable devices has presented their engineers with a whole new set of challenges, and the innovation employed to ensure that the durability of these devices approaches that of their hard-bodied rivals continue to evolve and amaze with each new generation.
The foldable era is finally here
There is still only a very small group of phone makers with the resources and technical know-how to successfully design and market an off-the-shelf foldable phone, and while Samsung remains the leader in the field , Huawei, Motorola, Oppo, Xiaomi and Honor all offer at least one form of foldable phone to call their own.
If you’re reading this around the time of Samsung’s August 2022 Unpacked event, the foldables of the moment are undoubtedly the new Galaxy Z Fold 4 and Galaxy Z Flip 4, however, the timing of their release actually means that they arrive sandwiched between other high-profile foldable phones from ambitious rivals.
The international launch of Huawei’s intriguing Mate Xs 2 still looks fresh, and the dust has barely settled on the Chinese launch of Motorola’s long-awaited Razr 2022 and Xiaomi’s new Mix Fold 2.
The increase in foldable competition at this point in 2022 suggests that much of the technical adversity these early foldable phones faced has already been overcome; making the creation of such products more accessible and cost-effective for a wider range of phone manufacturers.
Huawei’s new Galaxy Z Fold 4 and Mate Xs 2 represent two very different solutions to the large-screen foldable form factor (Samsung has two screens, with the larger foldable panel facing inwards, while the Mate Xs 2 uses a single, larger outer panel) and thanks to new technical insights from both companies, we can see what’s going on behind the scenes to make this new generation of foldables thinner, lighter, stronger and more durable.
Sharpen the hinge
Generally speaking, the more moving parts a machine has, the more potential points of failure it suffers from. Standard smartphones might pack a trio of buttons, maybe an OIS (optical image stabilization) system supporting at least one of their cameras, and a haptic motor inside for vibration, but that’s up to just about everything.
The hinge systems of vertically foldable phones like the Z Fold and Mate Xs series are full of dozens (if not hundreds) of interlocking parts that work in concert to give the device that part of a rigid spine. This key assembly more evenly distributes the force applied when the phone is opened or closed, while protecting the delicate ribbon cables and other components running between the two halves of the device.
We spoke directly to Huawei about improvements to the hinge system that facilitates the Mate Xs 2’s ‘dual-rotation Falcon wing design’ to find out what was being done to give the company’s latest handset a better shot at market supremacy. foldable phone.
When it comes to the hinge, the main upgrade seems to be the choice of materials from which the majority of the Mate Xs 2’s hinge is made and how it is produced.
Using a process called MIM (metal injection molding), the hinge is carved from high-density stainless steel that Huawei says is 50% stronger than what you’d get from “more conventional production techniques”, combined with a composite support structure that uses new lower density materials, making the Mate Xs 2 both 1.4 times more crush resistant, compared to the previous Mate X, but also lighter than before.
As the segment above from its August Unpacked event shows, Samsung took a decidedly different approach with the Z Fold 4’s hinge, essentially doing away with the longstanding gear system that’s inside every Fold. previous one and building a thinner and lighter mechanism instead. which relies on linear motion; tested to withstand over 200,000 bends over its lifetime.
It’s an approach that appears to have been applied to the Z Flip 4 as well, with the hinge protruding far less compared to 2021’s Flip 3.
Samsung has already shown how hard it goes to keep dust out of this complex hinge mechanism, with the silicone brushes being a key part of the assembly.
Samsung’s last two generations of foldables also score extra points for being the only devices of their kind to offer IPX8-certified water resistance.
There’s no point in beefing up the backbone of these high-end handsets if those all-important flexible displays can’t keep up.
Composite layers are the name of the game here, with Huawei’s Mate Xs 2 supposedly taking inspiration for its display construction from the screens of cars equipped with collision avoidance systems.
The unique foldable 7.8-inch flexible OLED on the Xs 2 is made up of a protective layer, a buffer layer, a barrier layer and the display layer, which sits on a titanium alloy in its construction, while the rear battery cover uses fiberglass less than 0.5mm thick to help support the phone thing but rope construction.
For its efforts, Huawei claims that the Mate Xs 2 is both 2.5 times more drop resistant and 2.8 times more shock resistant than its predecessor.
On the Z Fold 3, the screen digitizer (the part that converts your analog touch into a digital input signal) is backed by a metal layer, while the Z Fold 4 skips that layer, instead relying on a thin FRP (fiber-reinforced plastic) liner, now bonded directly to the digitizer for added strength.
The Z Fold 4’s main screen also features the company’s second-generation UTG (ultra-thin glass), which Samsung says offers 20% better scratch resistance.
A revised sponge layer also helps absorb shock more effectively, while S Pen support also lives on, aided by the S Pen Fold Edition’s spring-loaded tip, which puts less pressure on the panel than a conventional stylus. .
You’d think that to make these latest foldables sturdier – with their reinforced hinges and reinforced screens – they’d end up weighing the same as a small car.
However, as already discussed, thanks to a clever redistribution of components and better use of composite materials on both devices, the Z Fold 4 and Mate Xs 2 end up both thinner and lighter than their respective predecessors.
The Galaxy Z Fold 4 is 8g lighter than the 2021 Z Fold 3 (making it 263g), and it’s also 0.1mm thinner when unfolded; making it the thinnest and lightest of Samsung’s Fold devices to date.
Huawei’s efforts, meanwhile, make the Mate Xs 2 the thinnest and lightest foldable of its kind; measuring 5.4mm at its thinnest point, when opened (the Z Fold 4 is 6.3mm thick) and a relatively featherweight 255g.
Room for improvement
While the efforts of foldable makers like Samsung and Huawei are clearly leading to stronger, thinner, and lighter devices with each new generation, foldables continue to face many of the same challenges they faced when the category first appeared on the scene in late 2018/early. 2019.
The hope is that by the time foldable prices drop, manufacturers will have managed to close the durability gap we see right in front of our eyes.
If you’re already sold on the current assortment of foldable phones, check out our list of the best foldable phones or, if not, our more general overview of the best phones overall might do the trick.