Breakthrough Artificial Retina Enables Dual-Modality Vision

Researchers have developed a novel implantable artificial retina device that converts near-infrared (NIR) light into electrical stimuli for retinal neurons. The technology, detailed in a recent article published in the journal Nature Electronics, offers a promising path toward restoring vision while preserving natural sight.

The device uses a specialized optical filter to selectively transmit near-infrared light for artificial stimulation while allowing visible light to pass through to the eye's natural photoreceptors.

Innovative Device Design

The core of the system is an ultrathin NIR-transmission filter made from layers of amorphous silicon and silicon dioxide. This filter is a mere 360 nanometers thick and is positioned above an array of single-crystalline silicon phototransistors.

The filter's key function is to block visible wavelengths while transmitting NIR light to the phototransistors beneath. Once stimulated, these phototransistors generate electrical signals.

These signals are delivered to retinal neurons via 3D liquid metal micropillar electrodes, composed mainly of eutectic gallium indium. To ensure safety and efficiency, the electrodes are coated with a parylene C film and functionalized with platinum nanoclusters to reduce electrical impedance.

A sophisticated multilayer optical filtering system provides angle selectivity, which is crucial for reducing interference from ambient background NIR light.

Performance and Biocompatibility

Extensive testing has validated the device's functionality and safety:

• Optical Performance: The NIR-transmission filter successfully demonstrated selective properties, passing targeted infrared wavelengths while effectively blocking visible light.
• Electrical Response: Electrophysiological tests confirmed the phototransistor array's sensitivity and response under NIR illumination.
• Biocompatibility: Human retinal pigment epithelium cells maintained high viability when cultured directly on the device material.
• In Vivo Safety: No evidence of inflammation or tissue damage was found six months after implantation in healthy mice.

Most significantly, mice implanted with the device exhibited measurable cortical neural responses to NIR light stimuli, responses that were completely absent in control groups. Furthermore, the device did not impair the test subjects' normal perception of visible light.

Technical Specifications and Potential

The device's design allows for significant customization and advanced features:

• Filters can be tuned to different central wavelengths (e.g., 950 nm, 1000 nm, 1050 nm) through precise layer engineering.
• The angle-selective filters enhance signal clarity by primarily accepting light from near-normal incidence angles.
• This architecture enables simultaneous dual-modality vision, where artificial NIR perception is layered atop natural visible-light sight through precise spatial and spectral control.

Reference: The full research is available in Nature Electronics (DOI: 10.1038/s41928-026-01601-8).