The startup announced the funding round in a post on Musk’s X social network, formerly known as Twitter. The deal was led by Founders Fund, a venture capital firm backed by billionaire Peter Thiel. 

Neuralink is the best-known player in a growing field of brain technology companies. Partly spurred by Neuralink’s high profile, investors have backed dozens of other startups exploring similar technology. Startups in the neurotechnology field raised $143 million this year through June 26, according to PitchBook data. That compares to $278.1 million in all of 2022 and $518.9 million in 2021. One rival, Synchron Inc., enrolled its first patient in a US clinical trial last year, beating Neuralink to that milestone. 

Neuralink recently received approval from the US Food and Drug Administration to conduct human clinical trials. The company is developing a small device that uses electrode-laced wires to link the brain to a computer. Placing the device requires drilling into the skull.

Musk’s startup has previously raised concerns within animal rights groups for its testing on primates. Earlier this year, the US Transportation Department began an investigation into the company after an animal advocacy organization said it obtained emails suggesting the startup did not follow proper procedure when shipping possibly hazardous materials.