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 ve 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?

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 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.

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