Needle-thin brain implant can record, deliver drugs and stimulate multiple regions

A collaborative team from the Technical University of Denmark, the University of Copenhagen and University College London has created a novel brain electrode named the microfluidic Axialtrode. The implant consists of a sub-half-millimetre polymer fiber that houses a light-conducting core, eight micro-channels for fluid flow, and thin metal wires for electrical recording. In mouse experiments, the fiber delivered blue and red light to activate neurons, recorded electrical activity from shallow and deep structures, and injected different compounds at points spaced nearly three millimetres apart, all without apparent discomfort to the animals.

The flexible, soft material reduces tissue irritation compared with traditional silicon probes. While currently intended for research into neural circuits underlying epilepsy, memory and decision-making, the creators envision therapeutic uses that combine precise drug delivery with stimulation. The team is pursuing patents and evaluating steps toward clinical testing, acknowledging that extensive validation and regulatory approval are still required.