How Apple’s Watch is Tricking our Minds
By Dr. Micah Yairi, Phorm’s Co-Founder and CTO
The new MacBook Pro track pad and Apple Watches have a new type of user interface. Apple calls it it’s “Taptic Engine”. It does a neat trick. Unlike most magic tricks that fool your eyes, this one fools your sense of touch. When you press on the trackpad, you feel it move down and “click” like on any other lap top track pad. The cool part about Apple’s is that the pad is not moving at all. Instead, Apple has developed an elegant and very fast (“low latency”) pressure sensor and vibration actuator system that creates a very unique vibration.
When you press on the track pad, the force sensors that surround the pad detect how hard you are pressing. A light press does nothing – just moves the mouse. But press more firmly, and the pressure signal from the force sensors exceeds a pre-determined threshold. When that threshold is passed, the computer interprets that to mean you want to “press down” and click the pad. It then sends a patterned vibration through the stiff trackpad which your finger feels.
What’s weird is how you perceive the vibration. It does not feel like a phone vibrate or a subwoofer. It feels just like a “click”. This happens because of our biology of touch. Specifically, your hand and fingers have four or five different types of mechanoreceptors – sensors in and under your skin that send signals to your spinal cord and brain about what you are feeling (For example this how we know we are feeling fur and not a stucco wall). Two of those types of mechanoreceptors are very sensitive to different types of vibration. If you stimulate them the right way – with the right vibration frequencies and magnitudes – the signals that they send to your brain are very similar to those that they send when you click on a regular keyboard key. So, by combining a lightning fast force sensor and vibration actuator, it really feels like you are pushing down the trackpad, even though it is not being depressed.
Why do it?
For the watch there is, of course, a very small screen. To get the most usability and to expand the sensory experience/interaction is important. This is what creates the value of the product and why we justify spending 500+ dollars on it. Adding this taptic engine is a way of making the interaction more immersive, to create more features and be user controllable.
Rumor: if they add this to the surface of the iPhones, it will simulate the feeling of hitting real buttons… An elegant new industrial design for their touchscreen. However, there is still no tactile cue that allows you to navigate the screen. For an awesome typing experience you need to complete the magic circle: Input orientation, and confirmation. Phorm’s technology creates tactile cues that you feel and allow you to navigate around a keyboard, completing the circle.