AirPods

Overview

I'm really proud of this product.

But in the beginning, it was a real ugly duckling. The initial concept from ID was a cabled headset - imagine two earbuds connected by a short cable, with an iPod-shuffle-esque bluetooth device hanging in the middle. It was unusable - with so much hanging mass, the earbuds would just fall out with any minor movement.

Recognizing how flawed the concept was, I tinkered with a secret concept on the side - one with no cables at all - and eventually devised a realistic architecture with two independent battery-powered headphones charged by a case.

This became the AirPods, which grew into a multi-billion dollar business for Apple.

Today, although I'm an extremely proud PodFather - this thing still haunts me. It's an icon, ubiquitous in popular culture, and part of my daily life. However, it has a limited battery life expectancy, but it's not repairable nor recyclable - so it's ultimately going to be landfill. The same goes for every other product I made at Apple. Years later, coming to this trashy realization inspired me to learn more about sustainable design in grad school, and apply those techniques on all my future creations.

Design Challenges

Architecture. Each earbud had to fit a vast array of hardware, including a giant battery, speaker, 2 microphones, bluetooth chip, bluetooth antenna, proximity sensor, connector, and various supporting components on a flexible PCBA. Balancing all the independent design constraints within a tiny form factor was quite tricky.

Bass port reduction. In order to achieve our target acoustic response, the bodies of air have to resonate properly with the driver, and require very precise tuning. Working closely with the acoustic engineers, we methodically modeled and reduced each chunk of the system - successfully reducing the bass port volume by about 50%.

Laser welding. One of the key enablers to forming such a small bass port was rethinking how it was manufactured. In this case, we chose to employ a new technique of laser welding a separate part - from the outside in. It sounds simple, but getting a laser to pass through Arctic White plastic is nearly impossible - but it eventually worked.

Connectors. This one was a wider team effort across headphone, case, and connector designers. It was essentially a tuning effort of headphone retention magnets versus connector spring force - but tricky to nail in close proximity to the case lid magnets.

Antenna performance. Early prototypes were admittedly flawed - we tried to make the flex itself into a bluetooth antenna, but manufacutring tolerances resulted in poor reception. After I left, the team pivoted to an off-the-shelf antenna component.