A research team led by Associate Professor Takashi Ikuno from Tokyo University of Science has developed a revolutionary self-powered artificial synapse that mimics human color vision while requiring minimal energy, potentially transforming edge AI applications.
The device, detailed in a paper published in Scientific Reports on May 12, 2025, integrates two different dye-sensitized solar cells that respond to various wavelengths of light. Unlike conventional systems that require external power, this artificial synapse generates its own electricity through solar energy conversion, making it ideal for edge computing applications where energy efficiency is crucial.
The synapse can distinguish colors across the visible spectrum with a remarkable resolution of 10 nanometers, approaching human visual capabilities. It produces opposite voltage polarities under different colored light—positive for blue and negative for red—enabling it to perform complex logic operations without additional circuitry.
"The results show great potential for the application of this next-generation optoelectronic device to low-power artificial intelligence systems with visual recognition," explains Professor Ikuno. When tested in a reservoir computing framework, the system achieved 82% accuracy in classifying 18 different color-motion combinations using just a single device, compared to the multiple photodiodes required in traditional approaches.
This breakthrough addresses a significant challenge in deploying advanced vision systems in edge devices, where power and computational constraints have traditionally limited capabilities. The technology could enable more efficient visual processing in smartphones, drones, wearable healthcare devices, and autonomous vehicles.
The researchers envision widespread applications for their innovation, including as low-power optical sensors in standalone smartwatches and medical devices, potentially reducing costs significantly compared to current technologies. With machine vision increasingly critical to modern technologies, this self-powered synapse represents a major step toward bringing sophisticated computer vision capabilities to everyday devices with minimal energy requirements.