Apple’s 13-inch MacBook Pro with Retina Display got some significant updates last week alongside the big Apple Watch and new MacBook announcements, and one of those was a brand new trackpad that features Force Touch pressure sensitive and a Taptic Engine for haptic (vibration) feedback. Repair experts iFixit took the new computer apart, and the most illuminating part of their teardown was the close-up it provided on the new trackpad’s design.
The particulars of the new trackpad design were partly revealed on stage – Apple showed the part as a key feature in its new MacBook design video and presentation. The one in the new 13-inch Retina MBP is slightly different, owing to the fact that there’s still room in the case to support a physical button-style trackpad like the one that ships in all other exiting Mac laptops, but at heart it’s the same combination of sound and haptics to produce a 100% accurate illusion of a physical click, even when no such click actually exists.
As Matthew Panzarino explained in an earlier post, the new trackpad design actually doesn’t move – or only moves on a microscopic scale – yet feels like the existing clicky design, albeit with a user-customizable degree of ‘clickiness’ controlled via software. iFixit’s teardown shows that the trackpad is supported by four spring mounts and a panel on the underside that likely isn’t present on the new MacBook’s version, but that it has the same Force Touch engine, which is a series of wire coils wrapped around a ferromagnetic core that creates the vibrations your finder translates as clicks.
To vary the strength, iFixit guesses that Apple will selectively activate either only some or all four of the ferromagnetic cores found inside the trackpad’s taptic engine. iFixit also notes that, in keeping with Apple’s assurance that there’s no real movement going on here, the construction includes no linear oscillators in the mechanism (which is what traditional vibration feedback like the kind found on your phone generally uses).
As for pressure detection, iFixit hazards a guess that they come via very small strain gauges mounted on flexible metal supports that read how much flex they experience and translate that into a read on how much pressure is being applied.