Google explains how it came up with the Pixel Fold hinge that keeps the device looking thin

The Pixel Fold hinge is the reason why the upcoming foldable lies completely flat when open. It is a 180-degree custom built fluid friction hinge that is out of the way of the internal screen when the device is unfolded as Google mentions in a blog post it released today about the Pixel Fold hinge. Why does this matter? As Google explains, "With other foldable devices you have the hinge components under the display, which drives up the thickness. So with our hinge, we moved these hinge components entirely to the ends of the device, out from under the display, which makes it much thinner."

That certainly makes sense and while Google had to design a hinge that would keep the svelte measurements of the Pixel Fold, it also had to create one that could stand up to the constant use expected of a hinge found on a foldable phone. Googler George Hwang, the product manager for the Pixel Fold, revealed how hard it was to design such a component. "We definitely had our work cut out for us," George said. "To put it simply, this is the most complex product I’ve ever worked on."

So how did Google come up with the design for the Pixel Fold hinge? First, they took boxes of hinges to the lab. They also looked at paper and books. Why? As Google Industrial Designer Sangsoo Park notes, "“We wanted to recreate the way you can hold and close a book with one hand, and we wanted to replicate how both sides of it seamlessly blend together when shut." Park said that one book that they obsessed over was a passport.

When deciding what form factor to employ for the Pixel Fold, Park looked down at a passport in his hand and had a epiphany. “I noticed it had a nice proportion when closed and opened. It feels like a little bit of a metaphor, too — your passport holds your memories and it’s where so many of your stories begin. And it’s thin and pocket-able enough to carry everywhere we go."

Google worked on the torque needed to open and close the Pixel Fold in an effort to make it all feel effortless. Park says that the torque settled on leaves the Pixel Fold user with a satisfying vacuum effect. Not only does it feel great, when closing the device it also creates a pleasing sound. Product Manager Hwang notes, "You get this satisfying clap when it shuts, and we really liked it."

To make sure that the Pixel Fold hinge could survive years of usage, Google created a prototype that was opened and closed manually over and over and over and over and over and over...you get the point. Eventually, Google built a machine to automatically open and close Fold prototype models. Park said, "We wanted it to firmly close, so we needed to balance the magnets to find that happy place."

Besides getting feedback from machine testing the hinge, Google also collected feedback from users testing the crucial component. Product manager Hwang said, "We heard from users that they were concerned about the hinge holding up which is why we obsessed over building the most durable hinge possible. The Googler thought about people like him who constantly are clicking their pens in meetings.

Google decided to build the hinge out of heavy-duty stainless steel, which is more durable than aluminum. And as Park points out, it also has a nice shine! 

The Pixel Fold can be pre-ordered exclusively from the Google Play Store and will be released on June 27th. It features a 5.8-inch OLED external display with a 1080 x 2092 FHD+ resolution with a 120Hz refresh rate. The internal display is a 7.6-inch OLED panel with an 1840 x 2208 resolution and a 120Hz refresh rate.