A research team led by Associate Professor Takashi Ikuno from Tokyo University of Science has created an artificial synapse that could revolutionize how machines see the world. Their innovation, published in Scientific Reports on May 12, 2025, mimics human color vision while eliminating the need for external power sources.
Unlike conventional machine vision systems that capture and process every detail, requiring substantial power and computational resources, this new device works more like the human eye. By integrating two different dye-sensitized solar cells that respond differently to various wavelengths of light, the artificial synapse generates its own electricity via solar energy conversion while distinguishing colors with remarkable precision.
The system can detect color differences with a resolution of 10 nanometers across the visible spectrum—approaching human visual capabilities. It also exhibits bipolar responses, producing positive voltage under blue light and negative under red light, enabling it to perform complex logic operations that would typically require multiple conventional devices.
To demonstrate real-world applications, the researchers used their device in a physical reservoir computing framework to recognize different human movements recorded in red, green, and blue. The system achieved an impressive 82% accuracy when classifying 18 different combinations of colors and movements using just a single device, rather than the multiple photodiodes needed in conventional systems.
The implications of this research extend across multiple industries. In autonomous vehicles, these devices could enable more efficient recognition of traffic lights, road signs, and obstacles. In healthcare, they could power wearable devices that monitor vital signs with minimal battery drain. For consumer electronics, this technology could lead to smartphones and augmented/virtual reality headsets with dramatically improved battery life while maintaining sophisticated visual recognition capabilities.
"We believe this technology will contribute to the realization of low-power machine vision systems with color discrimination capabilities close to those of the human eye," remarked Dr. Ikuno. This breakthrough represents a significant step toward bringing efficient computer vision to edge devices, enabling our everyday technology to see the world more like we do.