Apple's first foldable smartphone, called the Duo, made its official debut at the company's Surprise and Shine event this week, bringing with it several noteworthy engineering revelations. Among them is the use of artificial intelligence and 3D printing technology in the design and manufacture of the device's central hinge - one of the most structurally demanding components in any foldable device.
The Duo marks Apple's long-anticipated entry into a product category that has attracted considerable consumer interest over the past several years. Foldable smartphones have been offered by a number of manufacturers, yet the category has struggled with a persistent challenge: the physical demands placed on a device that bends repeatedly tend to accelerate wear and compromise durability in ways that conventional smartphones simply do not face. Many foldables on the market have shown measurable degradation over time, raising questions about their long-term reliability.
AI and Precision Manufacturing at the Core
Apple's senior vice president of hardware technologies, Johny Srouji, addressed the engineering approach behind the Duo's hinge during the event presentation. He described a manufacturing process that relies on artificial intelligence to match individual hinge components with their optimal housing counterparts, ensuring precise mechanical alignment across every unit produced.
"During manufacturing, we use AI algorithms to precisely match each individual hinge with its best-fit housing to ensure perfect alignment, and a confocal laser progressively scans the topology of every single unit and 3D prints up to 25 micro layers of a custom photopolymer to eliminate residual waviness," Srouji said at the event.
The process Srouji outlined involves a confocal laser that scans the surface topology of each individual device unit. Based on that scan, a 3D printing system then deposits up to 25 micro layers of a custom photopolymer material to correct any surface irregularities. The goal is to eliminate what engineers refer to as residual waviness - minor imperfections in the folding panel that can affect both the visual quality and the mechanical performance of the display over time.
Additional Durability Measures
Beyond the hinge engineering, Srouji outlined several other design choices intended to improve the Duo's resistance to everyday wear. The device features a custom nano-texture surface finish, which Apple says significantly reduces glare and reflections on the display. This type of finish has appeared on other Apple products, including certain iPad and Mac display configurations, and is generally applied to improve visibility in bright lighting conditions.
Apple also incorporated a multilayer lamination strategy into the Duo's construction. Lamination in display manufacturing refers to the bonding of multiple layers - including the display panel, touch sensor, and protective cover - into a tightly unified structure. A well-executed lamination process can reduce the likelihood of delamination, which is a known failure point in foldable devices that experience repeated flexing.
Questions About Long-Term Performance Remain
While Apple's described approach to the Duo's construction reflects a high degree of engineering attention, the true test of these measures will only emerge through extended real-world use. Foldable devices from other manufacturers have, in some cases, been marketed with strong durability claims that proved difficult to sustain under typical consumer conditions. Independent testing and long-term user experience will ultimately determine whether Apple's manufacturing innovations translate into meaningful improvements in the Duo's lifespan compared to competing foldable products.
The Duo represents a significant product category expansion for Apple, and the engineering decisions behind its construction - particularly the AI-assisted hinge matching and laser-guided 3D printing process - signal the extent to which the company has invested in addressing the well-documented shortcomings of foldable smartphone hardware before bringing its own version to market.
