A brain-computer interface (BCI) translates brain activity into commands that a machine can understand and act upon. The concept, once confined to science fiction, has become a rapidly advancing field of neurotechnology with real clinical applications. BCIs can be invasive (requiring surgical implant placement on or in the brain) or non-invasive (using external sensors placed on the scalp), with fundamental trade-offs between signal quality and surgical risk.
The modern BCI landscape spans multiple approaches and companies. Neuralink, founded by Elon Musk, has begun human trials with its N1 implant, which uses over a thousand thin electrodes inserted into the motor cortex. Synchron has taken a less invasive route with its Stentrode device, delivered through blood vessels to sit inside the brain's venous system. On the non-invasive side, companies like Kernel and Emotiv are developing headset-based systems for consumer and research applications using EEG and other modalities.
Clinical BCIs are already restoring communication to people with paralysis — the BrainGate consortium has enabled patients to type, browse the web, and control robotic arms using only their thoughts. The technology is expanding beyond medical applications into gaming, productivity, and neurofeedback wellness. Despite enormous progress, challenges remain around long-term implant stability, wireless bandwidth, and scaling manufacturing to consumer price points. For deeper coverage, see BCIIntel.