Citing supply chain sources, Economic Daily News says the testing involves evaluating the use of OLED or Micro-LED display technology, because the choice of either screen will affect the subsequent assembly methods.Earlier leaks indicate that Apple may be working on a folding iPhone that use two separate displays connected by a hinge, rather than a single screen like the Samsung Galaxy Fold.
Apple is also said to have asked Foxconn to evaluate the bearings (the folding component) of the devices with over 100,000 opening and closing tests. The report notes similar tests for regular laptops requires them to be opened and closed between 20,000 and 30,000 times.
Source: MacRumors