New brain implant can shine light, record signals and deliver drugs at once.

An international team developed the microfluidic Axialtrode (mAxialtrode), a flexible fiber thinner than a sewing needle that combines light delivery, electrical recording and microfluidic drug channels in one device. In tests on mice the implant stimulated neurons with blue and red light, recorded activity in cortex and hippocampus, and delivered substances at different depths up to about 2.7 millimeters apart.

Researchers at several European institutions have built a flexible, multi‑function brain implant called the microfluidic Axialtrode, or mAxialtrode. The fiber is thinner than a sewing needle and brings light delivery, electrical recording and drug delivery together in a single probe. It is made from soft polymer optical fibers and has a specially angled tip designed to interact with different brain depths. The developers say the design aims to reduce tissue irritation compared with harder, flat-ended implants. Key findings: - The mAxialtrode is a flexible fiber under half a millimeter wide and combines an internal light core with eight microscopic channels about 20 micrometers wide. - The device is produced by a thermal‑drawing process and can include hair‑thin metal wires for electrical recordings alongside microfluidic channels for drugs. - An angled tip spreads electrodes and fluid ports across different depths, allowing interaction with multiple brain layers rather than a single point. - In mouse experiments the implant delivered blue and red light, recorded electrical activity from the cortex and hippocampus simultaneously, and injected different substances at depths up to about 2.7 millimeters apart. - The team reported the polymer fiber appeared to trigger less inflammation than a conventional flat-end fiber; the work was led by researchers at the Technical University of Denmark with collaborators at the University of Copenhagen, University College London and others, and received funding from the Lundbeck Foundation and the European Innovation Council. Summary: The mAxialtrode was developed to support basic research by enabling simultaneous optical stimulation, electrical recording and localized drug delivery across brain layers. The researchers note the device may point toward clinical applications in the future, but say extensive testing, further development, regulatory review and patenting work remain underway; exploring clinical trials is reported as a potential next step.