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Here's How Neuralink Is Modifying Its Brain Chip for Second Human Patient

The second human patient will recieve the implant 'in the next week or so,' Elon Musk says.

 & Michael Kan Principal Reporter

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As Neuralink prepares to install its brain chip into a second human patient, the company has come up with several ways to ensure the implant remains in place. This includes inserting the chip’s electrodes deeper into the subject’s brain.

The surgery should occur “in the next week or so,” Neuralink founder Elon Musk said during a Wednesday presentation.

The sci-fi-like technology promises to help people with physical disabilities control their PCs or smartphones by converting their brain signals into Bluetooth-based commands. But one challenge facing Neuralink is the chip’s thread-based electrodes, which attach to the patient's brain and are used to detect their neural activity.

In March, Neuralink’s first human patient, Noland Arbaugh, demonstrated the brain chip in action by using it to control his laptop and play games such as Civilization VI. But weeks after his surgery, 85% of the thread-based electrodes became displaced from his brain. 

Although Arbaugh can still use his brain chip at high levels, Neuralink wants to ensure the threads remain in place for future human trials. One reason for the slippage is an air pocket forming inside the brain during surgery, the company said today.

(Credit: Neuralink )

“During any typical brain surgery, a small amount of air is introduced into the skull. That’s because neurosurgeons like to have as much room as possible around the brain,” said the company’s head neurosurgeon, Matthew MacDougall. 

“That air pocket, we think, may have contributed to eating up some of the threads’ slack as the air bubble migrated to be under the implant, pushing the brain away from the implant,” he explained. In response, the company wants to keep the next patient's carbon dioxide levels in a normal range during surgery to prevent the brain from expanding or shrinking. 

The company plans on better “sculpting” the implant to prevent a gap from appearing under the skull. “That will put the implant closer to the brain, and eliminate some of the tension on the threads.” MacDougall said.

(Credit: Neuralink )
(Credit: Neuralink )

“The depth of the bottom of the implant is actually thinner than the average human skull,” he added. “We didn’t do this in the first human participant because we didn’t want to manipulate any of their tissue that we didn’t absolutely have to.”

The other major change is that Neuralink plans on inserting the thread-based electrodes a few millimeters deeper into the subject’s brain. This means even if the threads partially retract, the electrodes should still be deep enough in the brain to remain useful and detect neural activity.

(Credit: Neuralink )

The second human patient wasn't identified. But during a Q&A with Twitter/X users, Musk said the company hopes to install the brain chip in more than two patients this year to potentially “high single digits.” Depending on regulatory approval, Neuralink envisions expanding the chip to thousands of patients within a few years.

About Our Expert

Michael Kan

Michael Kan

Principal Reporter

My Experience

I've been a journalist for over 15 years. I got my start as a schools and cities reporter in Kansas City and joined PCMag in 2017, where I cover satellite internet services, cybersecurity, PC hardware, and more. I'm currently based in San Francisco, but previously spent over five years in China, covering the country's technology sector.

Since 2020, I've covered the launch and explosive growth of SpaceX's Starlink satellite internet service, writing 600+ stories on availability and feature launches, but also the regulatory battles over the expansion of satellite constellations, fights with rival providers like AST SpaceMobile and Amazon, and the effort to expand into satellite-based mobile service. I've combed through FCC filings for the latest news and driven to remote corners of California to test Starlink's cellular service.

I also cover cyber threats, from ransomware gangs to the emergence of AI-based malware. In 2024 and 2025, the FTC forced Avast to pay consumers $16.5 million for secretly harvesting and selling their personal information to third-party clients, as revealed in my joint investigation with Motherboard.

I also cover the PC graphics card market. Pandemic-era shortages led me to camp out in front of a Best Buy to get an RTX 3000. I'm now following how the AI-driven memory shortage is impacting the entire consumer electronics market. I'm always eager to learn more, so please jump in the comments with feedback and send me tips.

The Best Tech I've Had:

  • My first video game console: a Nintendo Famicom
  • I loved my Sega Saturn despite PlayStation's popularity.
  • The iPod Video I received as a gift in college
  • Xbox 360 FTW
  • The Galaxy Nexus was the first smartphone I was proud to own.
  • The PC desktop I built in 2013, which still works to this day.

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