Wireless skull mounted device uses patterned light to send signals into the brain

by Clarence Oxford
Los Angeles CA (SPX) Dec 09, 2025

Northwestern University researchers have developed a fully implantable wireless device that sends information directly to the brain using light, bypassing the body's usual sensory pathways. The thin, flexible system sits under the scalp on top of the skull and delivers precise patterns of light through bone to activate neurons across the cortex. In mouse experiments, the team showed that animals could learn to interpret these artificial light patterns as behavioral cues and use them to make decisions and complete tasks without relying on sight, hearing, or touch.

The device builds on earlier wireless optogenetics technology from the same group, which used single micro LEDs to control neurons and influence social behavior in freely moving mice. The new platform replaces the single emitter with a programmable array of up to 64 micro LEDs, each roughly the width of a human hair, enabling complex time varying patterns that resemble distributed neural activity during natural sensations. Because real sensory experiences recruit wide cortical networks rather than small isolated clusters, the multi region design is intended to better match how the brain normally encodes information.

Instead of penetrating brain tissue through a cranial opening, the current device conforms to the skull and shines light transcranially, which reduces invasiveness while still reaching cortical circuits. The system is powered and controlled wirelessly, removing the need for fiberoptic tethers or bulky external hardware that can restrict natural behavior. The emitters use red light, which propagates efficiently through tissue and can activate light sensitive neurons even though the source remains above the skull.

To test whether the brain could treat these signals as meaningful inputs, the researchers engineered mice with cortical neurons that respond to light and trained them on a port selection task. During trials, the implant delivered a specific spatiotemporal sequence of light across four cortical regions, analogous to tapping a coded message onto the brain surface. The mice quickly learned to distinguish the target pattern from many alternative patterns and consistently visited the correct port to obtain a reward, demonstrating that they detected and correctly interpreted the artificial input.

After confirming that patterned transcranial optogenetic stimulation can generate usable artificial perceptions, the team plans to test more complex sequences and measure how many distinct patterns the brain can learn and discriminate. Future versions may increase the number of LEDs, reduce spacing between emitters, expand coverage across the cortex, or use wavelengths that reach deeper structures. Researchers note that the platform could ultimately support applications such as sensory feedback for prosthetic limbs, artificial inputs for vision or hearing restoration, non drug modulation of pain, rehabilitation after stroke or injury, and brain based control of external devices.

The study, titled Patterned wireless transcranial optogenetics generates artificial perception, appears in Nature Neuroscience and describes the miniaturized fully implantable encoder and its performance in detail. The work received support from the Querrey Simpson Institute of Bioelectronics, the U.S. BRAIN Initiative, the National Institute of Mental Health, One Mind, the Kavli Foundation, the Simons Foundation, the Alfred P. Sloan Foundation, and the Christina Enroth Cugell and David Cugell Fellowship.

Research Report:Patterned wireless transcranial optogenetics generates artificial perception