Apple's first foldable iPhone will feature an innovative liquid metal hinge and has now shipped prototype units to carriers around the world for testing, the leaker known as "Fixed Focus Digital" today said.

In a new post on Weibo, Fixed Focus Digital said development and production related to the foldable are now "progressing rapidly." The claim arrives one day after the leaker reported that the foldable iPhone would feature vapor chamber cooling.

The liquid metal hinge detail is significant in light of the ongoing debate over the device's production difficulties. Earlier reports from the leaker known as "Instant Digital" attributed manufacturing problems to the hinge failing Apple's quality control standards under prolonged, high-frequency open-and-close testing. Fixed Focus Digital previously pushed back on that characterization, arguing the hinge was not the primary source of difficulty, and today's post appears to position the hinge as a resolved and confirmed element of the design.

Liquid metal is an amorphous metal alloy with a notably higher strength-to-weight ratio than conventional metals, along with superior resistance to corrosion and wear. Apple has used liquid metal in limited contexts before, most notably for the SIM ejector tool included with iPhones and for certain internal components, but its application in a structural hinge mechanism would be a far more demanding use of the material. The foldable iPhone is expected to fold and unfold hundreds of thousands of times over its lifespan, placing exceptional stress on the hinge, and liquid metal's durability properties make it a more capable material than conventional alloys.

Apple's history with liquid metal stretches back over 15 years. In 2010, Apple signed an exclusive deal with Liquidmetal Technologies, receiving a perpetual worldwide license to commercialize the material in consumer electronics. In the years that followed, the company used liquid metal only for minor components such as the SIM ejector tool, with the material proving difficult to scale for larger structural parts. Apple repeatedly renewed its arrangement with Liquidmetal Technologies, and the material has continued to surface in patent filings covering hinges and other moving parts.

Supply chain analyst Ming-Chi Kuo first reported in March 2025 that the foldable iPhone's hinge would use liquid metal, with Dongguan EonTec named as the exclusive supplier of the alloy. A subsequent January supply chain report corroborated the liquid metal hinge plans, but in April Fixed Focus Digital cast doubt on the material choice, claiming Apple was still weighing liquid metal against 3D-printed titanium alloy.

The claim that prototypes have reached global carriers for testing represents a meaningful milestone, suggesting the device is now sufficiently complete to undergo the network compatibility and carrier certification process that precedes commercial launch. DigiTimes reported in April that mass production was planned to begin in July, and Bloomberg's Mark Gurman reported the device remains on track for a September debut alongside the iPhone 18 Pro and ‌iPhone 18 Pro‌ Max, though he noted the timing was not yet final at the time of writing.

The foldable iPhone is expected to feature a 7.8-inch inner display, a 5.5-inch cover display, the A20 chip, the C2 modem, Touch ID in place of Face ID, and two rear cameras, with pricing rumored to start at around $2,000.

Source: Macrumors