Brain-Computer Interface: From Experimental Cutting-Edge Technology to Large-Scale Implementation, Opportunities and Challenges Coexist

I. Introduction: Brain-Computer Interfaces on the Eve of Mass Production

On December 31, 2025, Elon Musk announced a major update via the X platform, explicitly stating that his brain-computer interface company Neuralink will commence large-scale mass production of its devices in 2026, implementing a highly streamlined, almost fully automated surgical procedure. This news, reported by global authoritative media like Reuters and Business Insider, quickly sent shockwaves through the industry, marking a critical juncture where BCI technology officially transitions from the experimental phase to preparation for commercial mass production.

Currently, brain-computer interfaces have become a core arena for competition among global tech giants and research institutions, with Elon Musk's Neuralink, Sam Altman-backed Murts Labs, and others actively making strategic moves. From medical restoration to human-machine symbiosis, from technological breakthroughs to ethical scrutiny, brain-computer interfaces are not only reshaping the relationship between humanity and technology but may also redefine the very form of life's existence.

II. Technological Foundation: The Contest Between Two Paths and Core Evaluation Metrics

2.1 Core Principle: The Signal Bridge Between Brain and Machine

The essence of a Brain-Computer Interface (BCI) is a bridge connecting the brain to external machines. The human brain consists of approximately 86 billion neurons; all thoughts and actions transmit information via neuronal firing. The core task of a BCI is to read (decode) and write (encode) these neural electrical signals, enabling interaction between "thought" and external devices. Currently, the technology can already read brain signals from paralyzed patients, decode them, and achieve basic applications like controlling a mouse, playing games, or manipulating a robotic arm to grasp objects.

2.2 Divergence in Technological Paths: Invasive vs. Non-Invasive

Current BCI technology is primarily divided into two main paths, each with distinct advantages and disadvantages in terms of safety, signal quality, and application scenarios, creating a clear competitive landscape.

Invasive Brain-Computer Interfaces, represented by Neuralink, employ a core method of creating a coin-sized opening in the skull, passing through the skin, skull, and dura mater to insert electrodes finer than a human hair directly into the brain's cortex to collect signals. The significant advantage of this path is high signal quality, as electrodes make direct contact with neurons; however, its drawbacks are equally prominent, being invasive and carrying risks of surgical complications and long-term biocompatibility issues.

(Semi) Non-Invasive Brain-Computer Interfaces, represented by the ultrasound technology used by Sam Altman-backed Murts Labs, do not require insertion into the brain, being completely non-invasive or only semi-invasive (not penetrating the dura mater). They utilize ultrasound to collect blood flow signals around active neurons (neural activity requires blood supply). Their greatest advantage is minimal damage to the brain, with the difficulty of semi-invasive surgery being comparable to "picking your nose"; however, the core challenge lies in the 0.5 - 1.5 second delay between blood flow signals and neural electrical signals, making decoding significantly more difficult.

2.3 Key Evaluation Metrics: Resolution Determines Technological Height

There are two core dimensions for evaluating the development level of BCIs: one is spatial resolution, i.e., the number of neurons that can be monitored; the other is temporal resolution, i.e., the frequency of capturing neuronal firing per second, which needs to meet microsecond-level monitoring standards.

Comparing current technologies, Neuralink's invasive approach has achieved a temporal resolution of 10 microseconds. In terms of spatial resolution, through 64 electrode threads with 1024 contacts, it can capture signals from approximately 2000 neurons in total. However, the limitations are significant: compared to the total of 86 billion neurons, 2000 is merely "a drop in the bucket." The detection area covers only about 1.3/1000 of the brain's surface area, with an insertion depth of only 3-5 millimeters (the brain's depth is about 80 mm). In contrast, the non-invasive approach of ultrasound BCIs holds an advantage in spatial coverage; theoretically, one probe can cover 1/4 of the brain, and four can achieve full coverage. However, the shortcomings of poor temporal resolution and signal delays of about 1 second are difficult to avoid.

III. Global Competition: Neuralink's Mass Production Ambition and Technological Breakthroughs

3.1 Neuralink: From Technological Breakthroughs to Scalable Implementation

Since its founding in 2016, Neuralink has undergone nearly a decade of development, achieving a valuation exceeding $9 billion, a team size of nearly 300 people, and completing a full cycle of hardware R&D, chip iteration, animal testing, and human clinical trials. The core support for its 2026 mass production plan is a series of technological breakthroughs and milestone achievements.

Core Technical Parameters: Neuralink's implantable chip is the N1 chip, measuring approximately 23mm × 8mm (the size of a coin), integrating 1024 electrode channels. Each channel can independently collect neuronal firing signals, with electrodes distributed across 64 flexible threads 20 times finer than a human hair. The supporting R1 surgical robot possesses micron-level operational precision, capable of inserting electrodes into specified locations at a speed of six threads per minute while avoiding dense brain vasculature.

Latest Surgical Breakthrough: Electrode threads can now pass directly through the dura mater without needing excision, which Musk calls a "major breakthrough." The new generation surgical robot has reduced the single implantation time from 17 seconds to 1.5 seconds, and the entire surgery can be completed within 1 hour. The goal is to achieve outpatient-surgery-level fully automated operations in the future, eliminating the need for a surgeon's involvement.

Clinical Trial Progress: As of late 2025 to early 2026, approximately 12-20 patients have had the device implanted (Musk mentioned it was close to 20), primarily covering patients with severe paralysis, ALS, etc. Early patients like the first recipient, Noland Arbaugh, have used the device for over 21 months with stable and continuously improving functionality. Some patients can already control a computer cursor, type, play games, browse the web, post, and even manipulate robotic arms to perform physical actions like eating and grasping objects. Others have begun taking university courses, giving speeches, or using CAD software again to design parts, enabling remote work.

Three-Phase Roadmap (2026-2028): Phase One "Telepathy" is currently underway, enabling spinal cord injury patients to control phones, computers, and other devices with their minds, completing the commercial loop. Phase Two "Blindsight" is a key focus for 2026, bypassing the eyes to encode images captured by a camera into electrical signals directly input into the brain's visual cortex, restoring vision and even enabling infrared/ultraviolet/radar vision. Phase Three "Deep" targets deep brain regions to treat diseases like depression and Parkinson's, touching the core domains of human emotion and consciousness regulation.

2025 Milestone Achievements: Completed first implants in the Middle East/UK/Canada, obtained FDA Breakthrough Device designation for speech restoration, secured $650 million in funding, and significantly improved precision with the new-generation surgical robot, laying the foundation for 2026 mass production.

IV. Current Limitations: Multiple Gulfs Remain from "Consciousness Immortality"

Despite rapid progress in BCI technology, current capabilities still have significant limitations, and there remains a long distance to the distant vision of "consciousness immortality."

4.1 Signal Reading: Only Able to "Eavesdrop" on Scattered Commands

If the brain is likened to a command center with 86 billion workers, current BCIs are like bugging devices placed in a corner with poor signal, only able to "hear" scattered words (like "raise hand," "move") shouted by a few dozen nearby, loud workers. They then infer intent from these words to control external devices. Their application remains limited to helping paralyzed patients improve their quality of life and cannot achieve more complex conscious interaction.

4.2 Signal Writing: Far from Achieving "Knowledge Upload"

Current technology is far from capable of directly uploading knowledge or memories into the brain as seen in science fiction, for three core reasons: first, insufficient resolution to decode complex consciousness and memory; second, the brain's unique structure, employing a "memory-computation integrated" model where consciousness and memory result from the combined action of multiple brain regions, not encoding in a single area; third, human understanding of how the brain works is still less than 1%. Current writing applications are limited to stimulating known specific brain region neurons via electrical or ultrasonic means to treat neurological diseases like pain, insomnia, Alzheimer's, stroke, and epilepsy.

4.3 Personalization Challenge: Individual Differences in Signal Encoding

BCIs exhibit highly personalized characteristics; each person's brain signal encoding is completely different. For example, the same signal might represent "kick leg" in Brain A but "drink water" in Brain B. Therefore, subjects require extended training post-surgery to allow the machine to "learn" their unique signal patterns for effective control, which also increases the difficulty of widespread technology adoption.

V. Future Outlook: The Convergence of BCI + AI + Embodied Intelligence

The future development of BCIs hinges on technological convergence, namely the synergistic development of BCI + Artificial Intelligence (for rapid decoding) + **Embodied Intelligence (for manipulating the physical world)**. Industry predictions suggest that in the more distant future (e.g., 30 years from now), if the following breakthroughs can be achieved, it may open up new possibilities for "consciousness continuation": seeing every action and every firing of all 86 billion neurons, completely understanding the brain's working mechanisms, and achieving consciousness carrier transfer.

This consciousness carrier transfer might manifest in two forms: one is placing memories and consciousness into a robot, continuing thought processes and playing a human role; the other is, like "grafting," connecting the central nervous system via BCI to a new carrier like a bionic body to continue "living." Musk further proposes the ultimate goal: achieving a whole-brain interface, increasing the number of electrodes to over 25,000, enabling direct interconnection between the human brain and the cloud, bridging the vast gap between human language output bandwidth (tens of bits per second) and AI data throughput (trillions of bits per second), preventing humans from losing competitiveness in the future.

Looking at near-term goals, 2026 will be a critical year for advancing BCI technology: Neuralink's Blindsight project is expected to commence trials with its first patient; Musk is "very confident" about restoring full-body motor function (animal testing is complete, human verification is imminent); clinical trial scales will further expand globally, and technological safety and efficacy will receive more validation.

VI. Ethical and Social Challenges: Questioning Boundaries Amidst Technological Sprint

While propelling human progress, BCIs also bring a series of ethical and social challenges, becoming an unavoidable core issue.

6.1 Risk of Social Fracture: Death Equity and the Intelligence Divide

If BCI technology advances further, it could break humanity's last line of equitable defense—death. In the process of popularization, if high-end brain "plug-ins" that enhance memory and computational power emerge and are expensive, they could lead to wealth-based disparities in intelligence, creating an insurmountable divide. "Knowledge changes destiny" could morph into "recharging changes species."

6.2 Privacy and Free Will Crisis: The Risk of Thought Datafication

When the brain is directly connected to the network, thoughts, memories, and dreams become storable, analyzable data streams. This poses two core risks: first, security vulnerabilities—hackers could invade the brain; if the device is infected with a virus or attacked, humans could "crash" or be controlled by AI. Second, commercial alienation and free will manipulation—companies could implant advertisements or suggestions into the subconscious, manipulating human desires and choices, completely undermining the foundation of free will.

6.3 Technological Ethics Controversy: Experimental Cost and Development Pace

Neuralink's development history has been marked by numerous ethical controversies: reportedly, since 2018, in animal experiments on pigs, sheep, monkeys, etc., issues like chip breakage, intracranial infection, and cerebral cortex damage led to the deaths of at least 1500 animals. Human trials also encountered malfunctions; the first patient, Noland Arbaugh, experienced partial electrode thread retraction within weeks, causing chip function failure. The fourth patient reportedly had implant rejection and even suicidal tendencies. Furthermore, of the eight founding scientists, only two remained by 2022. Departing members believed scientific development should proceed step-by-step, while the company's timeline was too aggressive.

6.4 The Original Intent of Technology: The Warmth of Life Continuation

The perspective of Cai Lei, a former JD.com vice president and ALS patient, captures the technology's warm undertone: to free life from the constraints of the physical body, allowing love and attachment to continue in a longer-lasting way. This also reminds the industry that discussing the essence of consciousness immortality and human-machine coexistence is not about breaking the equity of death but about endowing life with new possibilities and continuity. Technological development must adhere to the baseline of humanistic care.

VII. Conclusion: Standing at the Threshold of an Era Redefining Humanity

2026 will likely be the year Neuralink truly transitions from "experimental black tech" to a "scalable medical product," and will also become a critical node in the global BCI technology competition. Musk's mass production plan and vision of "human-machine symbiosis" are accelerating towards realization, securing a significant position in the global technological race.

We stand at the threshold of an era moving from repairing humans to enhancing humans, and potentially redefining humanity. Towards BCI technology, we should maintain awe but not resistance—technology itself is neither good nor evil; the key lies with those who wield it. In the future, it is crucial to prioritize establishing rules for brain-related technologies, preventing the future digital world from becoming a "cyber playground" for the few and a "digital prison" for the many, ensuring technology truly serves the continuation of life and the enhancement of well-being for all humanity.