Korean researchers’ single memristor replaces both the driving transistor and storage capacitor in micro-LED

For years, the display industry has chased micro-LEDs. These tiny lights promise screens that are brighter, more colorful, and far more energy-efficient than anything we've seen before. Imagine smartphones with vivid colors that pop under sunlight, AR/VR headsets with lifelike detail, or car dashboards that are both sharp and power-conscious. The potential is staggering.

But there's a challenge. Each micro-LED pixel relies on two small but essential components: a thin-film transistor (TFT) and a storage capacitor. As displays grow ever sharper, these components start to crowd the pixel, creating a bottleneck that makes ultra-high-resolution arrays complex, power-hungry, and expensive to manufacture. It’s a problem that has kept micro-LEDs from becoming mainstream—until now.

Published in the International Journal of Extreme Manufacturing (IJEM), Prof. Tae-Geun Kim's team at Korea University has found a clever way around this problem: a capacitor-free active-matrix (AM) driving circuit powered by a single memristor—a programmable resistor that "remembers" its resistance even when the power is off.

Traditionally, capacitor stores a pixel's brightness information while driving TFT regulates the current that lights up the LED. "So we asked a simple but critical question," said Prof. Kim. "Could one programmable resistor do the job of two devices? If so, it would rewrite the backplane architecture and remove a critical roadblock for micro-LED displays."

By carefully tuning the memristor's resistance, they demonstrated it can. The team built a small 12 × 12 micro-LED array where each pixel was driven by a germanium-based memristor with a high ON/OFF ratio and long filament lifetime. In their real-time experiments, adjusting the memristor's resistance directly controlled LED brightness with excellent stability—no storage capacitor required.

This result confirmed that the concept works and, importantly, it's compatible with existing display manufacturing processes.  It also marks the first experimental demonstration of a capacitor-free AM pixel for micro-LEDs. By replacing the entrenched 2T-1C circuit with a streamlined one-device solution, their implications are sweeping:

• higher pixel density for ultra-sharp AR/VR headsets and next-generation wearables
• lower power consumption for mobile and battery-constrained systems
• simpler manufacturing through fewer circuit elements and reduced wiring congestion.

"This is a fundamentally different way to think about pixels," Prof. Kim explained. "By merging memory and driving into a single element, we open the door to displays that are both more efficient and easier to build."

Prof. Tae-Geun Kim's team is now scaling the approach to larger and denser arrays (i.e., CMOS-based display), color displays, and extended reliability testing under real-world operating conditions. If successful, their single memristor-based technology may light the way forward for an industry that has long struggled to make micro-LEDs practical at scale.

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International Journal of Extreme Manufacturing (IJEM, IF: 21.3) is dedicated to publishing the best advanced manufacturing research with extreme dimensions to address both the fundamental scientific challenges and significant engineering needs.

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