Reliability: the top priority
Foldable phones, which often cost more than many traditional models, face a primary concern from buyers: reliability. In plain terms, reliability means durability, resistance to impact and abrasion. A 2023 market report on foldable phones in China found that 39.5% of users consider product durability the most important factor when purchasing a foldable phone.
The reason is clear: foldable phones have a high technology density and high repair costs. If a device is fragile, owners will treat it cautiously, which undermines the user experience regardless of other strengths.
The trade-off between thinness and durability
Making a foldable phone both reliable and thin is a technical challenge. Thickening the screen protection layer improves durability, but increases thickness and weight, and raises folding resistance. The industry needed innovations to reconcile those conflicting demands.
Rapid market adoption
Only a few years ago foldable phones were niche. In 2020, foldable phone shipments in China were just over 1 million units, while smartphone shipments in China were on the order of 300 million units. By 2022, foldable phone shipments in China grew by 154.4%, even as overall smartphone shipments declined by 3.5%. That divergence signaled growing market support for foldable designs.
Delivering a convincing large-screen experience
To win users, a foldable phone must deliver not only a large-screen experience but also thinness and reliability. For example, the Huawei Mate X3, introduced in March, offers a 7.85-inch unfolded screen while weighing less than some 6.7-inch slab phones. That combination of lightness, large screen, and improved reliability is central to product appeal.
Materials innovation
One notable approach to improving reliability without adding bulk is the use of a non-Newtonian fluid impact-resistant screen protector. Traditional methods increase film thickness to improve durability, which in turn increases folding resistance. Engineers sought a material that is flexible during normal folding but stiffens under impact.
Researchers developed an ultra-high molecular weight polymer with extremely high dynamic chemical bond density. Those dynamic bonds resist rapid impact without breaking, while allowing slow separation during normal folding, achieving the desired behavior at only micron-level thickness.
After extensive testing, including resolving problems with optical transmission and deformation, the team selected a high-transparency polysiloxane that meets display optical requirements. To ensure adhesion, they modified the polymer formulation to enable molecular-level bonding and used plasma treatment to convert hydrophobic surfaces to hydrophilic ones, allowing strong, reliable attachment of the layer to the display stack. The result is a flat, transparent, thin, foldable, and reliable large display.
System-level engineering and manufacturing
Material innovation is only one part of the solution. Achieving a high-quality final product requires integrated breakthroughs in design, materials, and manufacturing processes. For example, early simulation workflows could take days to build models and many hours to run simulations, limiting iteration speed and product refinement.
Improving simulation speed to produce near-real-time results enabled more aggressive optimization of structural elements. Engineers can now identify and remove redundant features without weakening the device, helping to minimize weight and thickness while maintaining strength.
These investments in tools and processes are an essential part of developing repeatable, manufacturable designs for foldable phones.
Hinge design and system integration
The hinge is a critical component influencing thinness and folding stability. Over several product generations, hinge designs have evolved from initial dual-rotation waterdrop hinges to multi-dimensional link mechanisms and then to refined dual-rotation waterdrop hinges that reduce multi-part mechanical transmission and structural redundancy. Shorter transmission paths, smaller size, and higher motion precision improve screen flatness when unfolded and provide a smoother, more reliable opening and closing feel.
Combining advanced hinge mechanics with improved materials such as impact-resistant glass and non-Newtonian fluid-based layers enhances both external and internal screen durability. Additional features such as IPX8 water resistance, improved optical zoom systems, and higher wireless charging power further broaden the functional value of modern foldable phones.
Software and connectivity
Large-screen software adaptation is also important. Optimized operating system support enables better multi-window experiences, including novel split modes that address app compatibility issues and unlock productivity gains on the larger display. Integration with satellite messaging and resilient communication technologies improves connectivity in low-signal environments.
Market impact and competition
As the foldable category attracts more manufacturers and the supply chain matures, competition intensifies. Market data show that companies that sustain deep, long-term investment in materials, design, and manufacturing can maintain high average selling prices and strong market positions. For example, in 2022 one manufacturer recorded a high average selling price and significant unit sales, demonstrating that product-driven differentiation can create a defensible competitive advantage.
Conclusion
The improvements in foldable phones reflect sustained, bottom-up investment in materials science, structural design, simulation and manufacturing process improvements, and system integration. Solving the core trade-offs between thinness, large displays, and reliability requires coordinated advances across multiple disciplines. Where those investments are made, foldable phones have moved from niche curiosity to a mainstream, high-value product category.
