https://www.vice.com/en_us/article/g5vyq3/researchers-use-invisible-finger-to-remotely-control-touchscreens

Researchers say they have found a way to use an hidden antenna array that emanates an electromagnetic field to tap and swipe on a phone remotely. They are comparing this technique to having an ”invisible finger” control your phone’s touchscreen.

The researchers performed various tests of their technique. In one of them, which can be seen on YouTube, they put a contraption made of an antenna array, a screen locator, and an injection detector in a cardboard box placed under a table. When they placed an iPad on top of the box, their contraption was able to detect the type of device that was placed on top of it and its orientation. The researchers said they were then able to send electromagnetic pulses to the iPad’s touchscreen simulating a touch.