The history of brain-computer interfaces (BCIs) dates back to 1924 with Hans Berger's discovery of human brain electrical activity through electroencephalography. However, in-depth BCI research started in the 1970s at UCLA. It was spearheaded by Professor Jacques Vidal, who also coined the term "brain-computer interface." In 1998, a breakthrough came when Phillip Kennedy implanted the first invasive BCI in a human.

Subsequent advancements include John Donoghue's introduction of the initial BCI game, "BrainGate," in 2003. In 2004, Matt Nagle became the first to receive an implanted invasive BCI system, offering promise to individuals with quadriplegia. After this, the 2000s witnessed a surge in BCI research, culminating in two seminal studies published in Nature in 2012 demonstrating how BCI systems could enable neural arm control and the restoration of arm movements following paralysis.

Brain-computer interfaces encompass three distinct categories: non-invasive, partially invasive, and invasive. Electroencephalograms (EEGs) are an example of non-invasive BCIs. They offer affordability and ease of use without necessitating surgery. However, their potential is constrained by the skull's signal-blocking nature, resulting in weaker signals.

On the other hand, invasive BCIs demand surgical implantation within the patient's head and entail higher risks. The benefit is that they can capture neuronal activity with better signal quality. This gives them the potential to help treat neurodegenerative ailments like paralysis, epilepsy, brain injury, amyotrophic lateral sclerosis (ALS), Parkinson’s disease, and Alzheimer’s disease. This could impact a huge number of people: as of 2007, one in six of the world’s population suffered from neurological disorders. As the global population continues to age, the demand for invasive BCIs and their potential applications is likely to rise with an increasing number of patients grappling with neurodegenerative disorders.

Neuralink, an invasive BCI company with a short-term goal of treating various neurological disorders such as quadriplegia, was founded by Elon Musk in 2016 with the intention of creating another “layer” to the brain to complement the functions of existing layers like the limbic system and the cortex. As Musk put it in a 2017 interview:

Neuralink seeks to accelerate this trend by turning human-computer interfaces into something more direct than current computing interfaces allow, namely through a BCI. Neuralink is one of the few companies that have conducted human BCI trials, with its first human trial beginning in September 2023, a second patient scheduled to receive implants in June 2024, and 10 others to begin trials by the end of 2024. Founded by Elon Musk who is known for his success with previous hard tech startups like Tesla, OpenAI, The Boring Company, and SpaceX, Neuralink has the opportunity to provide potential life-saving applications of BCIs at scale for the first time.

Neuralink was founded in 2016 by Elon Musk. Musk reportedly met with over 1K potential candidates before deciding on the founding team of Neuralink. The eight members of the founding team who joined Musk were Max Hodak, Benjamin Rapoport, Dongjin Seo (VP of Engineering), Paul Merolla, Philip Sabes, Tim Gardner, Tim Hanson, and Vanessa Tolosa. Hodak served as the President of Neuralink from inception through early 2021. As of 2024, Jared Birchall is the CEO of Neuralink. Birchall also works at the Musk family office Excession LLC as its managing director.

In January 2017, the company acquired the trademark "Neuralink" from neuroscientists Mohseni and Nudo. In April 2017, Neuralink was launched with a mission to develop advanced brain devices for treating significant brain-related illnesses. Beyond this immediate goal, Neuralink's long-term vision centers around people merging with AI. Musk was inspired by the science fiction concept of neural lace portrayed in Iain M. Banks' The Culture series.

Initially headquartered in San Francisco's Mission District, Neuralink later moved its base to Fremont, California. The short-term goal of the company is to solve debilitating brain and central nervous system ailments and in the long term, the company aims to create a generalized platform for the brain and achieve alignment with artificial general intelligence.

Neuralink’s product is a wireless fully implanted BCI. It can be broken down into three basic parts: an implant, an app, and a surgical robot. Elon Musk described the Neuralink product in a 2020 Neuralink livestream as “kind of like a Fitbit in your skull with tiny wires.” The N1 implant is also known as the "Link", This neural chip, the size of a coin, is surgically placed under the skull and is equipped with electrodes for recording and emitting electrical currents. It connects to neural threads distributed across different sections of the brain responsible for motor skills. The technology aims to decode and stimulate brain activity, enabling direct communication between human brains and computers. Neuralink is also working on a companion app that allows individuals to control a keyboard and mouse using only their thoughts.

Neuralink's primary goal is to facilitate communication between the brain and computers. Its implant records and interprets neural signals, transmitting information back to the brain through electrical stimulation. This breakthrough technology holds the potential to restore movement for individuals with paraplegia and grant vision to those born blind. To facilitate the intricate surgical process, Neuralink has developed a neurosurgical robot designed for full automation. Overall, the company is attempting to take a leap forward in making brain-computer interfaces more accessible and practical.

N1 Implant

The N1 Implant is a fully implanted neural recording and data transmission device with ~1K electrodes. According to the whitepaper published in 2019, previous versions of the link consisted of a panel of microchips, a battery, and ~3K electrodes distributed along neural threads thinner than human hair. The N1 Implant is intended to replace a piece of skull once implanted and would be completely invisible and able to transmit data wirelessly.

Source: Neuralink

In a 2020 product update, the N1 Implant became capable of capturing over 1K channels of information, with each channel transmitting data at a rate of 200 megabits per second. The device's size also shrank to that of a large coin, measuring 23 millimeters in width and eight millimeters in thickness. Additionally, all the wiring that was earlier required to connect the electrodes was condensed to within centimeter of the device itself. Close to 10 N1 Implant interfaces can be placed in a single brain hemisphere.

Biocompatible enclosure: The N1 implant is sealed in a biocompatible enclosure that can withstand physiological conditions several times harsher than those in the human body.

Source: Neuralink

Battery: The N1 implant is powered by a small battery that can be charged wirelessly from the outside via a compact, inductive charger. The implant’s battery has a one-day battery life.

Source: Neuralink

Chips and Electronics: Advanced, custom, low-power chips process neural signals, transmitting them wirelessly to the Neuralink application, which decodes the data stream into actions and intents.

Threads: The N1 implant contains arrays of flexible electrode threads with up to ~1K electrodes per array distributed across 64 threads. These highly flexible, ultra-thin threads are key to minimizing damage during implantation and beyond. The threads are 4 to 6 μm in width, which makes them considerably thinner than human hair.

Surgical Robot

The threads of the N1 implant are so fine that they can't be inserted by the human hand. Therefore, Neuralink built a surgical robot to reliably and efficiently insert these threads exactly where they need to be. The surgery that inserts the implant is bloodless, as the sensors in the robot guide the cutting blades so they avoid rupturing any blood vessels. The robot is capable of inserting six threads (192 electrodes) per minute. As one Neuralink VP described it:

Source: Card79

The entire process of getting the implant surgery should take place in less than an hour without the need for any general anesthesia, and the patient will be able to be discharged the same day. Neuralink intends to allow patients to control their devices with the help of a Neuralink app.

Customer

Neuralink does not have any customers yet as it is awaiting approval and is still in clinical trials. The implant is yet to be approved by the FDA for general use, although Musk stated in an April 2024 interview that he believed it would be able to achieve approval for general use within 1-2 years. If approved, the company will start implanting the link in people with paralysis, as Elon Musk stated in 2021:

The initial applications envisioned for Neuralink are to assist individuals with paralysis in utilizing their electronic devices and to provide vision restoration for those experiencing blindness. Later versions, according to Musk, will be able to “shunt signals from Neuralinks in brain to Neuralinks in body motor/sensory neuron clusters, thus enabling, for example, paraplegics to walk again.” In May 2024, Musk described the company’s next application as follows:

Market Size

The global BCI market was valued at $1.7 billion in 2022 and is expected to grow at a CAGR of 17.5% through 2030. Market growth is likely to be driven by improvements in technology, along with the increasing prevalence of neurodegenerative conditions like Alzheimer's, Parkinson's, and epilepsy, along with the improvement of BCI technology and its expanding applications.

Medical BCIs are anticipated to play a crucial role in addressing neurodegenerative conditions in the near future. According to the World Health Organization (WHO), the number of people living with dementia in 2017 was expected to more than triple from 50 million to 152 million by 2050. In addition, the WHO estimated in 2013 that between 250K and 500K people suffer a spinal cord injury (SCI) every year. Approximately 1.7% of the US population was dealing with paralysis as of 2016.

The impact of paralysis on a person's ability to effectively use computers or smartphones is significant. This limitation underscores the potential of BCIs, as they could empower individuals with paralysis to interact with technology more seamlessly. Projections indicate that affluent nations could see approximately 50 million potential beneficiaries of BCIs for medical reasons by the year 2025. This suggests a growing demand for BCI technology in order to enhance the quality of life for individuals with various medical conditions, ranging from neurodegenerative disorders to paralysis.

Synchron: Founded in 2012, Synchron is the primary competitor to Neuralink. The company has developed an endovascular brain-computer interface that can access every corner of the brain using blood vessels. Its device, Stentrode, is placed in a vein alongside the motor cortex and is designed to enable patients to wirelessly control digital devices. In 2020, Stentrode received a Breakthrough Device Designation from the FDA. In 2021, Synchron received an FDA Investigational Device Exemption to conduct trials of permanently implantable BCIs. As of April 2024, the company had implanted its device in 10 people.

The company has so far raised $145 million in total funding. In December 2022, the company raised a $75 million Series C led by ARCH Venture Partners. Other notable investors include Bill Gates and Jeff Bezos.

Blackrock Neurotech: Founded in 2008 and headquartered in Salt Lake City, Blackrock Neurotech is the earliest and most widely studied BCI with over 1.7K published studies and 19 years of human studies. The company is backed by Peter Thiel, who invested $10 million in 2021. The company’s core technology is based on Utah Array, a BCI that was first implanted in humans in 2004. The company’s device also received a breakthrough designation from the FDA in 2021. The company claims to have already installed its BCI in 31 patients across the world. However, Neuralink’s implant can capture more brain cell activity at multiple points and is wireless, whereas Blackrock Neurotech’s device captures activity at a single point and has wires. The company has raised $10 million in total funding, which is raised in a 2021 financing round.

Kernel: Founded in 2016, Kernel is building technology for non-invasively measuring the brain and building biomarkers. Kernel’s combination of hardware and software allows researchers to conduct advanced neuroscience studies without requiring large equipment such as an MRI machine. Kernel’s Neuroscience as a Service (NaaS) model has two components. Flux detects magnetic fields created by the collective activity of neurons in the brain (i.e. magnetic flux). Flow detects cortical hemodynamics, which is representative of neural activity (i.e. blood flow). In 2020, Kernel raised $53 million in Series C led by General Catalyst, bringing its total funding to $153 million.

CTRL Labs: Founded in 2015, Ctrl-labs is a New York-based startup that developed a wristband that translated neuromuscular signals into machine-interpretable commands. CTRL Labs's flagship product was the CTRL-kit, a wireless, non-invasive electromyography (EMG) device that translated neural signals into control. The CTRL kit was designed to be used for a variety of applications, including gaming, productivity, and healthcare. The company was acquired by Meta in 2019 for between $500 million and $1 billion. Andrew Bosworth, Facebook’s head of AR, explained the vision for its product under Meta like this:

Neurable: Neurable is a Boston-based company spinout from the University of Michigan’s Direct-Brain Interface Laboratory (UM-DBI) which launched in 2015. The company is working on building an “everyday” BCI. The company came up with smart headphones that have soft EEG sensors woven into the ear cushions. These headphones can detect patterns in brain activity with near lab-grade precision which allows users to control their smartphones, computers, and other devices with their thoughts. Its devices also measure brain activity to generate simple, real-time insights. In April 2023, Epson Corporation invested an undisclosed amount in Neurable, and its total disclosed funding is $9.8 million.

Paradromics: Founded in 2015, Paradromics is an Austin-based brain-computer interface (BCI) company that is working on bringing to market a direct data interface with the human brain, which will be intended to provide technology solutions to unmet medical needs. Its first clinical application is an assistive communication device that caters to patients who have lost the physical ability to speak or type. The company has so far received $70 million in venture investment and $18 million in public funding via NIH and DARPA.

Neucyber: In April 2024, a Chinese company called Beijing Xinzhida Neurotechnology publicly revealed Neucyber, which some were calling “China’s version of Neuralink”. The majority shareholder in the company is the Beijing municipal government, and it was reportedly tested on a monkey who was able to control a robotic arm with the company’s technology using its thoughts. The company has yet to begin human trials as of April 2024.

While Neuralink is still in the research stage and has not deployed a product, the company mentioned that the implant will be quite expensive at the beginning and anticipates that costs will decline rapidly from there to settle in the range of a few thousand dollars, including the cost of the robotic surgery. Musk compared the Neuralink implantation surgery to LASIK (refractive eye surgery) which cost $2.4K to $3.2K per eye in the US as of 2023.

In 2017, the company partnered with the University of California, Davis’s California National Primate Research Center (CNPRC) to conduct animal-based research. In 2020, they opened a vivarium for housing farm animals and rhesus macaques. In 2020, Neuralink also received FDA breakthrough device designation for limited human testing.

In August 2020, the company demonstrated its BCI devices in a pig named Gertrude for two months. The devices were implanted in the part of its brain that controlled the snout and showed real-time correlations between neural signals and Gertrude's snuffling. In April 2021 the company released a video of Pager, a nine-year-old Macaque, playing MindPong with a Neuralink device implanted in both sides of its brain.

In May 2023, the company received approval from the FDA to launch its first-in-human clinical study, which was a watershed moment having previously been rejected. This trial began in January 2024, when the first human successfully received a Neuralink implant. The patient was a 29-year-old who had been paralyzed from the neck down from a swimming accident 10 years ago, and the Neuralink implant enabled him to control a cursor and engage in hobbies like gaming.

In April 2024, Neuralink announced that it was partnering with Arizona-based Barrow Neurological Institute to kick off a clinical trial for its N1 implant, following the announcement of its first successful human trial in January 2024. In May 2024, Neuralink received FDA approval to implant a chip in a second patient, which it planned to do in June 2024. By the end of 2024, the company intends to have 10 other patients implanted with its device, and Elon Musk stated in an April 2024 interview that he believed that Neuralink would be able to achieve approval for general use within 1-2 years.

Neuralink’s latest round of funding as of October 2023 was a $280 million Series D in August 2023 at an undisclosed valuation, led by Founders Fund. The round brought the company’s total funding amount to $643 million. Before that, privately executed stock trades in June 2023 valued the company at $5 billion, compared to its $2 billion valuation in 2021. This 2.5x valuation surge followed the FDA's approval for the company to conduct in-human clinical trials in the same month.

BCI Market Expansion

Investor interest in BCIs is growing. The funding for brain-computer interface startups reached $531 million in 2021, an increase of almost four times compared to 2020. The sector is also attracting attention from medical device and pharmaceutical companies. Ongoing research focused on developing treatments for critical conditions such as brain and spinal disorders, sleep disorders, and cerebrovascular diseases is also anticipated to contribute to the expansion of the BCI market.

Regulatory Changes

The regulatory environment is adapting to reflect the growing interest in BCIs. For instance, Abbott obtained an FDA Breakthrough Device Designation for a deep brain stimulation system for treating depression. The NIH also provides grants to BCI companies as part of its BRAIN initiative (Brain Research through Advancing Innovative Neurotechnologies) which was set up in 2013. The overall funding limit for 2023 through this initiative is around $680 million.

A 2010 report on the FDA’s execution of authority over the regulation of medical devices in the US concluded that the FDA’s “ unpredictable, inefficient, and expensive regulatory processes are jeopardizing America’s leadership position in MedTech innovation”. However, the FDA has since evolved its stance on neural device development.

The FDA released a BCI guidance document in May 2021 entitled “Implanted Brain-Computer Interface (BCI) Devices for Patients with Paralysis or Amputation’”, acknowledging the potential benefits of implanted BCI devices for people with severe disabilities. To facilitate market access, the FDA established its “Breakthrough Devices Program”, which makes it mandatory for the FDA to respond to human-trial applications in under 30 days and thereby reduces the total time companies spend seeking agency approvals.

Technology Advancements

Advancements in computational and sensor technology are expected to drive growth in the BCI market. Over the past few years, the industry has seen improvements in not just the accuracy of brain-wave sensors but also in the quality of signal detection. To put things into perspective, BCI systems that existed before Neuralink have no more than 256 electrodes, with connectors that pass through the skin, requiring medical assistance to connect the BCI. Neuralink, by contrast, has over 3K electrodes per array. Neuralink also claims that the analog pixels are at least 5X smaller than other state-of-the-art devices.

Founding Team Exits

So far, six out of its eight founding members have left Neuralink. In 2021, Max Hodak, who was Neuralink's co-founder and president, left the company. The departure of so many founding members and also key employees is a cause for concern for Neuralink. It could signal that the company is facing internal problems, or that it is not meeting the expectations of its investors including Elon Musk. Ex-Neuralink employees have claimed that there is frequently intense pressure to deliver on unrealistic timelines, which may be contributing to employee dissatisfaction. There are also reports of Musk investing in its primary competitor Synchron amidst the delays in regulatory approval.

Safety Issues

Regulatory risks surrounding Neuralink primarily revolve around significant safety concerns associated with the device flagged by the FDA. These concerns include the device’s lithium battery which can potentially damage brain tissue. There is also a possibility of the implant's miniature wires migrating to unintended areas within the brain and uncertainties surrounding the safe removal of the device without causing damage to delicate brain tissue.

In May 2024, Neuralink’s first human patient reported that 85% of implant wires had become detached within a few weeks of the implant, a reportedly known issue to the company from animal testing. Addressing these potential hazards and ensuring the device's safety and effectiveness will be pivotal for navigating the regulatory landscape and obtaining approvals for Neuralink's neural interface technology. It will also be important to address these issues to win public trust and adoption if the company is able to secure approval for general use.

Adoption Challenges

The utilization of BCIs for commercial purposes may encounter public skepticism. A survey says that 83% of Americans wanted implants to be tested using a higher standard than applies to medical devices. The general public also foresees adverse consequences stemming from the widespread adoption of brain chips for cognitive enhancement, expressing concerns about both economic disparities and cybersecurity vulnerabilities. A few states in the US have passed laws banning invasive microchips or other implants due to privacy concerns. However, when it comes to solving for people with medical ailments such as paralysis, 77% of Americans supported the use of BCIs.

Reports of Animal Cruelty

In 2022, there were reports indicating that the company was under federal investigation due to concerns about potential breaches of animal welfare standards. This investigation was prompted by internal complaints from staff members, alleging that the company's animal testing procedures were being expedited, leading to unnecessary distress and fatalities among the test subjects. However, in July 2023, the Department of Agriculture (USDA) concluded that there were no violations of animal research rules other than a 2019 incident that the company had reported previously. However, the reputation risk to the company and the potential to run afoul of regulators still exists.

Drawing inspiration from the historical evolution of brain-computer interfaces (BCIs), Neuralink aims to bridge the gap between human cognition and artificial intelligence. By integrating BCIs into the human brain, Neuralink wants to create a future where paralysis is no longer a barrier to movement and communication, where mental health afflictions find new avenues of treatment, and where human’s understanding of the brain's intricacies deepens beyond measure. However, as with any innovation, challenges abound. Having secured ample funding and clinical trial approval, Neuralink is at the forefront of the effort to create commercially viable BCIs. These interfaces have the potential to address medical conditions that have remained unsolved by conventional pharmaceutical approaches.