Neuralink’s Human Trials: Progress, Challenges, and Future Outlook

On Tuesday (U.S. time), biographer Ashlee Vance reported that thousands of people are waiting in line to receive brain implants from Elon Musk’s Neuralink.

Neuralink performed 155 surgeries on sheep, pigs and monkeys in 2021 and 294 in 2022, but has not yet implanted devices in humans. Earlier this year the FDA approved a human trial, which Musk described as a “Fitbit on the skull.” In September the company began recruiting volunteers for its first human trial.

Neuralink plans 11 human surgeries next year, 27 in 2025, 79 in 2026, then a rapid increase to 499 in 2027 and 22,204 by 2030, projecting up to $100 million in annual revenue within five years.

The full translation follows: Elon Musk is preparing for what he calls the most important launch of his career—not cars or rockets, but a brain surgery. Neuralink is seeking volunteers willing to have a portion of their skull removed so a robot can insert many electrodes and ultra‑fine wires into the brain. After the robot finishes, the skull piece will be replaced by a coin‑sized computer that reads brain activity and wirelessly transmits it to a nearby laptop or tablet.

The ideal candidates are adults under 40 with quadriplegia, allowing the implant to be placed in the motor cortex hand‑knob area that controls hand, wrist and forearm movements. The goal is to prove the device can safely collect useful data from that brain region, a key step toward translating thoughts into computer commands.

SpaceX’s first three rockets exploded, but “we can’t mess up the first three human experiments.”

Several companies have built implants that let patients perform basic tasks with thought, but Neuralink’s ambitions are larger. Over the past four years the company has hinted at a future where anyone can undergo a 15‑minute robot surgery and emerge as a human‑machine hybrid capable of downloading information or uploading thoughts, as Musk claimed in 2019. The company originally hoped to start human trials in 2020.

While Musk’s track record shows he can achieve seemingly impossible goals, brain implants require a level of perfection unlike rockets or cars. Companies will not rush these devices to market without rigorous safety.

Other firms such as Synchron and Onward are already a year ahead of Neuralink in human trials. Nonetheless, Neuralink has attracted far more public attention, though some neuroscientists criticize it as hype. Animal‑rights groups have condemned its animal testing, and Musk’s controversial public persona raises concerns about large‑scale deployment.

Despite the concerns, Neuralink’s progress is exciting. If the implant works as intended, future iterations could dramatically improve the lives of millions with paralysis, stroke, ALS, hearing or vision loss.

Under Musk’s leadership, Neuralink has achieved significant technical milestones, but the pressure of successful human trials is unprecedented for the company.

Modern brain‑implant history began in the 1990s. Neurons fire in patterns that correspond to intended movements or speech; a well‑trained computer can, in theory, decode these patterns to infer intent.

The challenge is to place sensors as close to neurons as possible. External devices suffer from distance and interference, while the most precise signals come from electrodes placed beside brain cells.

“The long‑term goal is billions of people using this technology to unlock human potential beyond our biology.”

For two decades the Utah Array has been the standard brain‑implant: a small silicon square with ~100 rigid spikes that require a craniotomy to insert, connecting to an external computer the size of an ice cube.

Researchers have used the Utah Array to enable paralyzed patients to communicate and control robotic arms, but the hardware has remained largely unchanged for over 20 years and requires extensive support staff.

Neuralink was founded in 2016 with $100 million from Musk and has raised over $500 million, attracting venture interest in brain‑computer‑interface startups.

Most companies aim to create a brain‑scanning device that can leave the lab, with enough computing power to record massive data streams, transmit wirelessly, consume minimal battery, and stay cool.

Neuralink’s implant sits flush under the scalp, contains its own processing, communication and charging systems, and is being developed alongside a spinal‑implant to restore movement and sensation.

Past two years saw over 400 animal implant surgeries, preparing for human trials.

Neuralink’s device has over 1,000 electrodes, far more than competitors’ ~16. The implant integrates processing, communication, and power, with a battery lasting several hours and wireless charging via a custom “baseball‑cap” charger.

Musk also internalizes key manufacturing, even producing custom low‑power chips, and has turned the Fremont facility into a large‑scale implant production line with CNC machines, laser cutters, and climate‑controlled chambers for testing implant durability.

The company built its own surgical robot—a 2.1 m tall white cube with a camera, sensors, and a micro‑laser drill that inserts 64 wires (each with 16 electrodes) 5 µm thick, avoiding blood vessels and minimizing tissue damage.

From 2021‑2022 the robot performed 155 and 294 animal surgeries respectively. Human procedures are expected to take several hours for preparation and about 25 minutes for the actual implantation.

During a recent visit, Musk urged engineers to speed up the process, aiming for fully autonomous surgeries without human surgeons.

Musk’s management style, while driving SpaceX and Tesla success, also pushes aggressive timelines for Neuralink, citing the urgency of achieving AI symbiosis before artificial intelligence overtakes humanity.

22,204 human implant surgeries projected by 2030

Co‑founders Shivon Zilis and DJ Seo remain the only original founders; other early members have left to start similar ventures. Jeremy Barenholtz, a Stanford graduate, now serves as a CEO‑level executive and helped secure FDA approval.

In July 2022 the author visited Neuralink’s Fremont headquarters, observing a large open workspace where engineers and robots were displayed, and Musk, in a black suit with a Red Bull, questioned staff about competitor progress.

Synchron’s advantage is a minimally invasive “stent” that can be delivered via blood vessels, allowing paralyzed patients to browse the web, a benchmark Neuralink aims to surpass.

Barenholtz explained that the FDA wants at least a year between the first human surgery and subsequent trials; Musk found this “unacceptable” and pushed for faster approvals, likening it to SpaceX’s rocket testing approvals.

Later updates showed Neuralink’s interest in Onward’s spinal‑implant technology, which delivers electrical pulses to help paralyzed patients walk.

Neuralink also announced work on its own spinal implant to complement the brain device.

Engineers demonstrated a spinal prototype that enabled pigs to walk on a treadmill, integrating brain‑spine interfaces, machine‑learning models, and hardware improvements.

After a site visit, semiconductor engineers adjusted chip‑to‑thread connections, boosting manufacturing speed by 50% and reducing defects.

Neuralink has received thousands of patient applications and recently received FDA clearance for additional 2024 implants without a year‑long waiting period. Each surgery is estimated to cost about $10,500 in direct expenses, with insurers billed around $40,000. The company projects 11 surgeries in 2024, 27 in 2025, 79 in 2026, scaling to 22,204 by 2030.

Animal‑testing concerns

Animal testing remains controversial; reports describe pain and distress in monkeys and other mammals, with some being euthanized after severe complications.

Neuralink acknowledges early surgical errors, attributing them to human mistake rather than device flaws, and claims to have improved animal welfare in its own facilities.

The author observed a group of rhesus monkeys living for three years in the Fremont facility, many still implanted and providing neural data, while a few have been retired to sanctuaries.

Before entering the animal area, staff must wear protective gear and receive briefings; the enclosure includes toys, trees, music, and TVs showing nature programs.

The monkeys help validate the robot and implant performance, often playing computer games that translate brain activity into cursor movements.

Neuralink is relocating much of its animal work to a new Texas campus with larger facilities, including barns, pathology labs, and a sci‑fi themed staff bar, housing dozens of sheep, pigs, and monkeys equipped with battery‑powered implants.

From nose‑button controls on animals to scaling up to 22,000 human surgeries, the path is long; any surgical mishap could set the company back years. Future implants may feature 128 or more threads, longer battery life, and wireless overnight charging via a pillow‑integrated pad.

If successful, these advances could dramatically improve the lives of many, even if other companies become industry standards.