Apple made a big deal about the advanced technology it developed to facilitate the 3D Touch feature on the iPhone 6s. But engineers at the University of Michigan have not only recreated the feature such that it can work on any smartphone, they have also improved it by enabling phones to detect when they're being squeezed, too.
So how can additional interactive features be added to any smartphone without adding sensors or upgrading its hardware in any way? ForcePhone is a piece of software simply relies on two of the device's standard features: its speaker and microphone.
The software causes the phone to constantly emit an 18 kHz tone, which humans can't hear, but the phone's mic can. As a user presses on the touchscreen, or squeezes the phone's housing, the force of the interaction on the smartphone alters the sound of that 18 kHz tone. The software detects the difference, and translates the force into commands.
The ForcePhone software works a bit like a submarine's sonar, but instead of hunting for other underwater vessels or obstacles, it's using the subtle changes in sound to allow users to interact with their phones in new ways.
Imagine unlocking your handset with a specific pattern of squeezes as you remove it from your pocket, or upgrading your iPhone 4 to match the capabilities of the 6s with nothing but a free firmware update. For now, this is just a research project, but 3D Touch and squeeze detection could one day be a standard feature on every smartphone.