Neuralink's brain-computer interface uses 1,024 electrodes threaded into motor cortex neurons to decode intended movements into digital signals. The N1 implant chip processes neural spikes at ~200Hz sampling rate, transmitting wirelessly to decode arm/hand motion intent. First human patient (Noland Arbaugh, quadriplegic) achieved cursor control and typing via thought alone. The tech stack: custom ASIC for signal processing, flexible polymer threads (thinner than human hair) to minimize tissue damage, and a surgical robot for precise electrode placement avoiding blood vessels. Real breakthrough isn't "reading thoughts" - it's translating motor intent signals into actionable computer commands with <100ms latency. Current limitation: electrode count caps information bandwidth to ~8 bits/second for typing. Next gen needs 10x more channels for fluid communication.