Tiny TV Screens For AR/VR Headsets

One of the biggest blockers to the Metaverse is the discomfort of the headsets, which at best are like wearing a fanny pack on your face. But many companies are racing to create ever-smaller micro-displays that will enable more compact, higher-resolution and lower-power virtual and augmented reality devices.

At the vanguard of this microdisplay revolution is Silex Microsystems, a leading manufacturer in micro-electromechanical systems, or MEMS, tiny devices that act as accelerometers, pressure sensors and micro-displays.

“We are the largest pure-play MEMS foundry in the world,” Silex CEO and co-founder Edvard Kälvesten told Forbes, explaining that the silicon-based manufacturing process is similar to that of larger semiconductor chips.Silex does not design products of its own; it rather specializes in realizing the inventions of the world’s MEMS visionaries including household-name tech giants, the world’s largest medical and industrial companies and revolutionary startups

As part of this, Silex is enabling the development of Micro-LEDs, using extremely small light-emitting diodes to create high-resolution and bright displays. The small size of Micro-LEDs allows for pixel densities that surpass traditional display technologies. The smallest LEDs are around 50 microns in diameter and Kälvesten said Silex is working on reducing the size to 1-2 microns – about the size of a red blood cell.

“It’s like a very small TV screen,” Kälvesten said, adding that the displays are less than a centimeter square with a million or more pixels.

But shrinking the displays is just one part of the challenge. Silex is also working with its customers to optimize the optics tailored for these miniaturized displays. “We’re doing things with waveguides to create the optical 3d picture,” Kälvesten added. Waveguides are thin, transparent structures used to direct and manipulate light from a micro-display to the user’s eyes.

The smallest LEDs are around 50 microns in diameter and Kälvesten said Silex is working on reducing the size to 1-2 microns – about the size of a red blood cell.

Achieving extreme miniaturization while maintaining a pixel density high enough to deliver a truly immersive visual experience is the critical challenge.

“Everybody says ‘I will not wear any glasses,'” Kälvesten acknowledged. “But when you speak to these tech companies, Micro-LED displays embedded into waveguide-assisted AR lenses is what they’re telling us will happen.”

Silex is also working on developing the technical capabilities and unique process flows for their customers’ integration of MEMS microphones and speakers directly into VR and AR devices, enabling spatial audio experiences that map precisely to the simulated environment.

Of course, producing these incredibly high-resolution yet ultra-compact displays at a commercially viable scale and cost is no simple feat. Silex has had to navigate considerable manufacturing and technical hurdles, not to mention geopolitical tensions that restrict technology transfer.

The company is owned by a Chinese parent company, Sai Microelectronics, which acquired Silex in 2015. However, export controls prohibit Silex in Sweden from exporting know-how and technology to the mother company in China. Elaborate safeguards and regulatory compliance procedures ringfence Silex’s cutting-edge work from unauthorized dissemination.

Nonetheless, Kälvesten remains sanguine about the future, perhaps because he sees the MEMS industry itself as being on an inexorable growth trajectory.

The potential applications for MEMS foundry extend well beyond virtual reality. Kälvesten explains that for example, “Optical switching is now the largest application for Silex customers,” said Kälvesten, adding that optical switches are replacing electrical switches in data centers to communicate between microprocessors. While electrical switches rely on electrical signals for data transmission, optical switches use light signals for faster and more efficient communication.

“The MEMS market as a whole is experiencing explosive growth year after year, with new applications emerging constantly,” he said.