What Is a Brain-Computer Interface? The Companies Building the Next AI Interface

For most of computing history, humans have communicated with machines through keyboards, mice, touchscreens, and voice commands.

Brain-computer interface companies want to remove those middle steps.

A brain-computer interface, usually shortened to BCI, captures signals from the brain and translates them into commands a computer can understand. In early clinical applications, this could allow a person with paralysis to move a cursor, operate a device, or communicate using only their thoughts.

The long-term vision gets considerably bigger. Some companies believe BCIs could eventually restore vision, treat neurological conditions, control robotic limbs, and create a direct interface between humans and increasingly capable AI systems.

Investors are taking the possibility seriously. Neuralink, Synchron, Science Corporation, Merge Labs, Precision Neuroscience, Blackrock Neurotech, and INBRAIN Neuroelectronics have collectively attracted billions of dollars.

Here is how brain-computer interfaces work, where AI fits into the stack, and which companies are raising money to build them.

What is a brain-computer interface?

A brain-computer interface is a system that collects brain signals, analyzes them, and converts them into commands for an external device.

The simplest version of the process looks like this:

1. Sensors capture activity produced by the brain.
2. Software filters and processes the signal.
3. AI models look for patterns associated with an intended action.
4. The system translates those patterns into an output.
5. A computer, prosthetic, communication device, or other machine performs the action.

A person might imagine moving their hand, for example. The BCI detects the corresponding neural activity and converts it into movement of a computer cursor or robotic limb.

The National Institutes of Health describes a BCI as a computer-based system that acquires brain signals, analyzes them, and translates them into commands sent to an output device.

That definition sounds straightforward. The engineering is anything but.

Brain signals are noisy, highly individual, and constantly changing. Capturing useful signals requires specialized sensors. Interpreting them requires enormous amounts of data, sophisticated machine learning, and continuous calibration.

The three main types of brain-computer interfaces

The BCI market is splitting into three general technical approaches.

1. Invasive brain-computer interfaces

Invasive BCIs place electrodes directly in or on brain tissue. Companies pursuing this model include Neuralink and Paradromics.

Direct contact can produce higher-resolution neural data, which may make it possible to decode complex intentions such as speech or precise movement.

The tradeoff is surgery. Implantable devices face serious questions involving safety, durability, infection, tissue damage, device removal, and long-term regulatory approval.

The FDA evaluates implanted BCI systems as complete medical systems because risks can emerge from the way their individual components interact. Its guidance for implanted BCI devices covers testing, safety, biocompatibility, wireless communication, and clinical performance.

2. Minimally invasive brain-computer interfaces

Companies such as Synchron and Precision Neuroscience are trying to capture strong neural signals while reducing the burden of implantation.

Synchron’s Stentrode is delivered through a blood vessel instead of requiring open-brain surgery. Precision Neuroscience uses a thin electrode array designed to rest on the surface of the brain.

These approaches could make BCI procedures available to a larger number of patients if they prove safe, effective, and practical to implant.

3. Non-invasive brain-computer interfaces

Non-invasive BCIs attempt to read brain activity without placing hardware inside the skull.

The most familiar systems use electroencephalography, or EEG, with sensors positioned on the scalp. Other companies are exploring ultrasound, optical systems, and alternative methods for sensing or influencing activity deeper in the brain.

Non-invasive systems are generally easier to deploy, but the skull weakens and distorts the signals being measured. That creates a bandwidth problem. The safer interface often produces less precise data.

Merge Labs is one of the most heavily funded companies pursuing a non-invasive approach. It is exploring ultrasound and molecular technologies instead of conventional implanted electrodes.

Why brain-computer interfaces need AI

BCI hardware collects the signal. AI turns that signal into something useful.

Machine-learning models can be trained to recognize patterns connected to intended movement, attempted speech, visual perception, or other forms of neural activity. As the model receives more information from an individual user, it can become better at translating that person’s signals.

This makes BCI an unusual AI infrastructure category. The underlying data comes directly from the nervous system, but it still needs the familiar layers of the AI stack:

• Specialized data collection hardware
• Signal-processing software
• Machine-learning models
• Training and calibration data
• Real-time inference
• Applications built around the decoded output

Generative AI could also help complete partial signals. A BCI may only capture an imperfect indication of what a user wants to say. A language model can use context to predict likely words, phrases, or actions.

That could make communication faster, but it also creates an important design challenge: the system must preserve the user’s actual intent. A model that confidently predicts the wrong message would be more harmful than helpful.

Brain-computer interface companies that raised funding

BCI fundraising has accelerated as companies move from laboratory research into human trials and early commercialization.

Neuralink: $650 million

Neuralink raised a $650 million Series E in June 2025 from investors including ARK Invest, DFJ Growth, Founders Fund, Sequoia Capital, and Thrive Capital.

The company is developing an implanted neural interface that can translate brain activity into commands for computers and other devices. Neuralink said the financing would support the expansion of clinical trials and development of devices intended to restore communication and vision.

Neuralink is currently the best-known company in the sector and the clearest example of investors treating BCI as a potential platform rather than a single medical device.

Merge Labs: $252 million

Merge Labs emerged in January 2026 with $252 million in seed funding from OpenAI, Bain Capital, Gabe Newell, and other investors.

The company is exploring non-invasive technologies that use ultrasound and molecular mechanisms to interact with the brain. OpenAI is supporting the development of AI models capable of interpreting neural intent from limited and noisy signals.

A $252 million seed round is an enormous wager for a company still conducting foundational research. It also shows how closely some investors now connect the future of BCI with the future of artificial intelligence.

Science Corporation: $230 million

Science Corporation raised a $230 million Series C in March 2026 to support commercialization of its PRIMA retinal implant and expand clinical trials.

PRIMA is designed to restore a form of vision for people affected by geographic atrophy, an advanced form of age-related macular degeneration. The system combines an implanted retinal device with external hardware and software.

Science represents a more focused entry point into the BCI market. Rather than beginning with a general-purpose brain interface, it is pursuing a specific medical need with a measurable patient outcome.

Synchron: $200 million

Synchron raised a $200 million Series D in November 2025, bringing its reported total funding to $345 million.

Its Stentrode system is implanted through the jugular vein and positioned inside a blood vessel near the brain’s motor cortex. The company wants to let people with paralysis control digital devices without open-brain surgery.

The financing is intended to support commercialization of Synchron’s first-generation platform and development of its next interface.

Blackrock Neurotech: $200 million

Tether invested $200 million in Blackrock Neurotech in April 2024 through its Tether Evo division.

The transaction gave Tether a majority stake and valued Blackrock Neurotech at approximately $350 million. This was a strategic investment rather than a conventional venture round.

Blackrock Neurotech has been developing brain-computer interface technology for decades. Its systems have been used in research and clinical settings to help people control computers, robotic limbs, wheelchairs, and communication devices.

Precision Neuroscience: $102 million

Precision Neuroscience raised a $102 million Series C in December 2024, bringing its total funding at the time to $155 million.

Its Layer 7 Cortical Interface is a thin, flexible electrode array designed to rest on the surface of the brain. The company hopes this approach can capture high-resolution neural activity with less tissue disruption than electrodes placed deeper inside the brain.

The financing is supporting regulatory work, clinical development, engineering, and manufacturing.

INBRAIN Neuroelectronics: $50 million

INBRAIN Neuroelectronics raised a $50 million Series B in October 2024.

The Barcelona company is developing a graphene-based neural interface that can decode and modulate brain activity. Its initial therapeutic targets include Parkinson’s disease, epilepsy, and stroke rehabilitation.

Graphene is attractive because it is thin, flexible, conductive, and capable of supporting high-resolution neural sensing. INBRAIN is betting that new materials can improve the safety and performance of implanted interfaces.

Paradromics: $33 million

Paradromics raised a $33 million Series A in 2023 to advance its Connexus brain-computer interface.

Connexus uses hundreds of small electrodes to record neural activity at high data rates. The company’s first clinical target is restoring communication for people who can no longer speak because of conditions such as ALS, stroke, or spinal cord injury.

Paradromics has since received FDA authorization to begin a long-term human study, moving the company from preclinical development into one of the most consequential stages of BCI commercialization.

What the funding tells us

Three signals stand out.

First, investors are concentrating capital in companies that can pursue human trials, manufacturing, and regulatory approval. This is expensive hardware with medical-device timelines, so the leading companies need unusually large funding rounds.

Second, invasiveness has become a major point of competition. Neuralink and Paradromics are chasing greater signal quality through direct neural access. Synchron, Precision Neuroscience, and Merge Labs are exploring ways to reduce surgical risk.

Third, medical applications are driving the market today. Restoring communication, mobility, and vision gives BCI companies a more realistic path through clinical trials and reimbursement than immediate consumer brain augmentation.

The futuristic applications get the attention. The first meaningful BCI businesses will probably be built around specific medical problems with clearly measurable outcomes.

The bottlenecks ahead

Large funding rounds do not remove the central challenges facing brain-computer interfaces.

BCI companies still need to prove:

• Their devices remain safe over long periods
• Neural signals stay reliable as the brain and body change
• Hardware can be manufactured consistently
• Surgical procedures can scale beyond a few specialist hospitals
• AI models can accurately interpret user intent
• Patients, insurers, and healthcare systems will pay for the technology
• Sensitive neural data can be protected against misuse

Most implanted neurological devices face demanding regulatory standards. According to the FDA, neurological devices are generally classified as moderate-risk or high-risk products.

The winners will need more than a powerful demo. They will need clinical evidence, durable hardware, responsible data practices, and a repeatable path into healthcare.

The next interface for AI

Brain-computer interfaces sit at the intersection of artificial intelligence, robotics, semiconductor design, neuroscience, and medical devices.

That makes BCI one of the most technically difficult corners of the AI economy. It also makes it one of the most consequential.

The near-term opportunity is deeply practical: helping people communicate, move, see, and interact with computers. Over time, better sensors and more capable AI models could expand what these systems can decode and control.

The computer interface has evolved from the keyboard to the touchscreen to voice. The brain may eventually become another input layer.

Investors are already funding the companies trying to make that happen.

Frequently asked questions

What does BCI stand for?

BCI stands for brain-computer interface. It describes a system that captures brain activity and translates it into commands for a computer or another external device.

How does a brain-computer interface work?

A BCI uses sensors to collect neural signals. Software and machine-learning models then analyze those signals and associate them with an intended action, such as moving a cursor, selecting a letter, or controlling a prosthetic limb.

Do all brain-computer interfaces require surgery?

No. Some BCIs use implanted electrodes, while others use sensors placed on the scalp or technologies such as ultrasound. Non-invasive systems are easier to deploy but typically capture weaker or less precise signals.

How is AI used in brain-computer interfaces?

AI helps identify patterns within complex neural data and translate them into useful commands. Language models can also help predict intended words or phrases from incomplete signals, potentially making BCI-based communication faster.

Which brain-computer interface company has raised the most funding?

Neuralink is currently the most heavily funded dedicated BCI company. Its $650 million Series E in 2025 brought its publicly reported funding well above $1 billion.

Are brain-computer interfaces available to consumers?

Most advanced BCIs remain in research or clinical trials. Some non-invasive EEG devices are commercially available, but implanted systems intended to restore communication, movement, or vision still require extensive clinical testing and regulatory review.