Technology journalist Joanna Stern teamed up with hardware specialist Aron Cohen to see how Apple’s first foldable iPhone, the iPhone Duo, handles thousands of folds. Their experiment reveals a surprising twist in the phone’s hinge behavior.

Stern and Cohen built a custom machine they named Hingey, which could open and close the iPhone Duo automatically. Over four nights the device performed exactly 32,640 opening‑and‑closing cycles.

Before starting, Cohen used a calibrated push‑pull force gauge to record how much force was needed to open the hinge. After the 32,640 folds, the same gauge showed the hinge required slightly more force, meaning it had become a little stiffer rather than looser.

Stern reported that the increase in stiffness was almost impossible to notice during everyday use. This outcome runs counter to the common assumption that mechanical parts gradually loosen with repeated use.

The test suggests the iPhone Duo’s hinge may become marginally tighter after heavy folding, challenging typical durability expectations for foldable phones. It shows that repeated motion does not always wear a mechanism out, at least in the short term.