A foldable, or foldable, phone, unlike smartphones that are made of one piece, has a central hinge and two sides that fold. The hinge acts as a central axis for opening and closing the phone and connecting the two displays, which can also function as a single display. Over time, Samsung has developed a revolutionary hinge mechanism technology and the Galaxy Z Fold has continued to shrink in thickness so that the phone can be taken anywhere, anytime.
Samsung Newsroom showcases the evolution of the Galaxy Z Fold’s sleek form factor and stunning hinge design, now thinner, sturdier and more compact than ever.
[2019] Galaxy Fold
The origins of foldable phones
Folded fish: 15.7-17.1 mm Fish revealed: 6.9-7.6 mm Weight: 276 grams
Not only are people’s lifestyles changing, but so are their needs. And Samsung introduces new technologies every year to meet those new needs. First unveiled in 2019, the Galaxy Fold had an innovative design: it was the first smartphone to have a large display when unfolded, and was compact and portable when closed. Folding and unfolding felt natural, thanks to Samsung’s unique hinge technology.
The inward-folding hinge was not only familiar and easy to use, but also provided effective screen protection. The phone could be opened like a book and folded into the palm of your hand. The first Galaxy Fold was just 17.1mm thick when folded.
[2020] Galaxy Z Fold 2
Flexible Mode: Hideaway Hinge and Sweeper Technology
Folded fish: 13.8 – 16.8 mm Fish revealed: 6.0 – 6.9 mm Weight: 282 grams
The Galaxy Fold’s successor, the Galaxy Z Fold2, came out in 2020 and featured a completely new design. The most noticeable difference was the Hideaway Hinge, which seamlessly connects the smartphone’s body and allows it to fold and unfold seamlessly. Users can position the Galaxy Z Fold2 in different positions thanks to the Hideaway Hinge. With Flex Mode, they can easily take selfies and make video calls.
There were over sixty parts in the Hideaway Hinge, making possible the innovative dual CAM mechanism. This mechanism allowed the device to remain open or closed and activate the flex mode. By increasing the number of CAM parts and springs, the hinge could support wider angles. The Hideaway Hinge was designed in a way that makes the device even slimmer, with a folded thickness of just 16.8mm.
Opening or closing the phone inevitably leaves a gap between the front and the hinge. To bridge this gap, Samsung had to develop a durable and flexible solution that didn’t add extra bulk. Inspired by vacuum cleaner brushes, Samsung used finely chopped optical fibers called Sweeper technology. This technology protects the phone’s display from external dust and dirt that can enter through the opening.
[2021] Galaxy Z Fold 3
The biggest challenge facing the foldable device has been solved: water resistance
Folded fish: 14.4 -16.0 mm Fish revealed: 6.4 mm Weight: 271 grams
Nowadays, we take it for granted that smartphones are water-resistant. However, the hinges of foldable devices were still sensitive to water. If liquids such as drinks or rainwater leaked to the side, the device could be damaged instantly.
The outside of the display was surrounded by a rubber band to prevent dust and liquids from entering. The metal parts of the hinge were made of a corrosion-resistant material and coated with a lubricant. The end connecting the two parts was sealed with a cured silicone gasket (CIPG) to prevent liquid from entering the device. Additionally, flexible printed circuit board (FPCB) cables were used to protect vulnerable components.
The Galaxy Z Fold3 features an aluminum armor material, a durable material that can withstand external shocks and reduce the chance of deformation or scratches. This has allowed the design to become thinner and lighter.
Armor Aluminum is applied to the outer edges and hinge housing. In the Galaxy Z Fold3’s Hideaway Hinge, several parts are tightly assembled to enable Flex Mode. This requires the hinge housing to be made of durable materials.
The Sweeper technology, which closed the gap between the hinge and the body, has also been improved. As the device became thinner, the bristles became shorter, while the hinge remained protected from dust and external particles. As a result, the Galaxy Z Fold3 was no thicker than 16.0mm when folded.
[2022] Galaxy Z Fold 4
Thinner and lighter joint
Folded fish: 14.2 -15.8 mm Fish revealed: 6.3 mm Weight: 263 grams
The Galaxy Z Fold4, which was unveiled in 2022, was noticeably lighter and thinner. At 263 grams, the device weighed about 20 grams less than the Galaxy Z Fold2. The maximum folded thickness was 15.8mm, making it the thinnest foldable in the series at the time.
The Galaxy Z Fold4’s new hinge was 21 percent lighter than its predecessor, and enabled a wider and shorter cover screen. While the previous foldable used interlocking gears to smoothly fold and unfold the screen, the Galaxy Z Fold4 had a linear rather than rotating hinge motion. This dramatically reduced weight, thickness, and number of parts. The Galaxy Z Fold4 had the thinnest and lightest hinge at the time, without sacrificing strength.
[2023] Galaxy Z Fold5
Flexible Hinge: The Secret to a Fully Foldable Phone
Folded fish: 13.4 mm Fish revealed: 6.1 mm Weight: 253 grams
In 2023, the world was introduced to the next generation of foldable devices: the Galaxy Z Fold5 series. The traditional Hideaway Hinge was replaced by the new Flex Hinge. With improved flexibility and several new features, the Flex Hinge allowed the display to slide smoothly into the hinge, without creases or gaps.
This new folding mechanism results in the lightest and thinnest Galaxy Z Fold yet. The Galaxy Z Fold5 measures just 13.4mm when folded, more than 2mm thinner than its predecessor. It weighs just 253g – 10g lighter than its predecessor – making it even more compact when folded.
Samsung has been improving the Galaxy Z Fold series every year. Every detail has been carefully considered, from the internal mechanisms to the exterior design. The new hinges and slim design continue to make the Galaxy Z Fold even more user-friendly.
Discover the next generation of Samsung innovations at Galaxy Unpacked on July 10 in Paris.
