At the latest Galaxy Unpacked event, Samsung Electronics unveiled a new future of mobile possibilities with the release of the new Z Flip4 and Z Fold4 — representing a decade-plus journey to reinvent the smartphone to unlock new experiences for users.
As one of the first smartphone makers, Samsung recognized that true innovation doesn’t just come from the advancement of technology itself. True innovation unlocks new benefits that transform the lives of consumers and democratize innovation for everyone.
To help users better understand the foldable technology from a technical perspective, Samsung Newsroom spoke with Dr. Won-Joon Choi, Executive Vice President, Head of R&D Team of Flagships and Technology Strategy Team at Mobile eXperience Business, Samsung Electronics.
As the leader of Samsung’s flagship research and development team, the questions and answers below include some of the latest advances and exclusive information about the fourth generation of the Galaxy Z series.
Read on to learn more about Samsung’s goals for the Z Flip4 and Z Fold4 and the process behind the foldable technology that’s as dynamic as its engineering team.
Q: What is your approach to improving the hardware design of Samsung’s foldable lineup?
Not only have we accumulated technical knowledge from the previous three generations of foldables, but we have also received customer feedback along the way which has been extremely valuable in advancing the Z Fold4 and Z Flip4. When dealing with customer feedback, most of the time we have to overcome technological limitations, which require new approaches compared to conventional bar-type smartphones. To bring foldable technology to millions of people and generalize the foldable device category, we focused on the following areas: improving durability for everyday use, providing the perfect balance between on-the-go experiences and optimized big screen experiences and maintain the ultimate performance that is the foundation of Galaxy smartphones.
Q: How does the updated hinge in Z Flip4 and Z Fold4 make everyday use more comfortable for users?
For Z Flip, our users wanted the form factor to be even more compact. For Z Fold, our users liked taking advantage of both the main screen and the cover screen and accomplishing tasks with one hand.
So our solution was to redesign the hinge on both devices. Our previous hinge design was a feat of engineering and enabled the foldable experience we see today. However, we knew internally that we would need to simplify the design to manufacture it on an even larger scale and meet the needs of mainstream users.
By creating this new hinge, we were able to further refine the design of the Z Flip4 to make it even more compact. It also allowed us to change the dimensions on Z Fold4. Now, the device has a slightly wider and slightly shorter cover screen, which allows for a more comfortable experience while typing on the go and performing other tasks on the cover screen. While these under-the-hood changes may seem incremental, they greatly contribute to the consumer experience.
In addition to providing users with comfortable use, the hinge redesign also brings benefits to both manufacturing and longevity. We have reduced the number of components by 60%. That’s a feat in itself because it means fewer components might need fixing and it’s easier to manufacture on a larger scale.
Q: Z Flip and Z Fold users love creating content with high-quality cameras. Are the latest devices giving users new experiences or features?
We have taken care to upgrade the cameras of both devices. We wanted to offer our consumers the benefits of Nightography, first introduced on S22, on both Z Flip and Z Fold. However, this required the addition of larger camera lenses to bring in more light. By redesigning the hinge, we were able to secure more space for the component that could fit our new camera systems without making the device thicker.
Q: How the fHas our generation Z series been slimmed down? How will this benefit the end user?
Over the past generations, we have focused on reducing the weight of the Z Fold series. We know this is a hugely important factor in getting the right foldable products because the value proposition of these devices is to deliver new experiences without compromise.
This year we focused on reducing the screen and hinge weight, resulting in a device that weighs 263 grams, 8 grams lighter than the Z Fold3 and nearly 20 grams lighter than the Z Fold2 (282g). This subtle but continuous refinement makes a big difference over generations.
To achieve this, we have restructured and optimized the number of internal components, including the display and the hinge. Reducing the weight of the screen contributed a lot to the overall weight. We’ve redesigned the layer structure and materials, and in doing so, the Z Fold4’s screen is not only 15% lighter than the previous generation, but also 45% stronger. Combined with the redesigned hinge, which is 21% lighter than the one used on the Z Fold3, the Z Fold4 offers a noticeable difference in weight. This results in a more comfortable, portable and convenient user experience.
Q: Samsung has received feedback in the past regarding the Z Flip’s battery life. How has battery life been extended in the Z Flip4?
One of the biggest comments we got from Z Flip3 was about its battery life. Since a foldable smartphone is divided into two parts and connected by a hinge, its internal space is naturally limited compared to conventional bar-type smartphones. However, by making the hinge thin and reconfiguring the internal mechanical design, it allowed us to secure additional space for a larger battery. With more efficient performance, users can now enjoy longer battery life compared to the previous generation.
Q: Galaxy users care about having an immersive viewing experience on their devices. How and why has the Under Display Camera (UDC) on Z Fold been improved in this latest iteration?
We created UDC technology to provide an uninterrupted viewing experience on the 7.6-inch main screen. It was the first of its kind on a foldable, and with Z Fold4 we were able to make the experience even better.
We have reconfigured the pixels above the camera to improve the perceived resolution and thus make the camera even more imperceptible. We changed the layout of the subpixels from a cluster type to a scatter type, increasing the visibility of the grid pattern and improving text readability. As a result, watching content, playing games and reading are uninterrupted on the main screen.
Q: The key element of Samsung’s foldables is ultra-thin glass (UTG). Can you tell us more about how you created this durable material that can be bent hundreds of thousands of times?
When we developed the first generation of the Galaxy Fold, we made the foldable screens out of flexible polyimide. But we knew we’d need to do something more durable to make foldables mainstream.
This is how the first ultra-thin glass was created. It is a very complex material that has to go through countless steps from the raw material. We first receive thin sheets of glass, thinner than a human hair, from our partners before they are coated and cut to precise dimensions. Then we undergo a delicate process of smoothing and polishing the surface of the glass. This ensures that the material is structurally sound and ready to install. Finally, they undergo a rigorous durability test before being added to a Z-series device.
Each step has been refined every year to get us to where we are today, producing millions of components for our devices that are durable enough to give our users peace of mind in their daily use.