Imroatul Nasiyah
At the heart of this transformative technology is its astonishingly small size, coupled with its capacity for extremely high-speed data transmission. The device, christened the Biological Interface System to Cortex (BISC), is built around a single, ultra-thin silicon chip that creates a wireless, high-bandwidth link between the brain and external computing systems. A seminal study, published in the esteemed journal Nature Electronics on December 8th, meticulously details the architecture of BISC. This sophisticated system comprises the chip-based implant itself, a wearable "relay station," and the essential software infrastructure to power the entire platform.
Ken Shepard, the Lau Family Professor of Electrical Engineering, professor of biomedical engineering, and professor of neurological sciences at Columbia University, and a senior author who spearheaded the engineering efforts, highlighted the stark contrast between BISC and existing implantable systems. "Most implantable systems are built around a canister of electronics that occupies enormous volumes of space inside the body," Shepard explained. "Our implant is a single integrated circuit chip that is so thin that it can slide into the space between the brain and the skull, resting on the brain like a piece of wet tissue paper." This unprecedented thinness and unobtrusive nature mark a significant departure from current bulky and more invasive BCI technologies.
The potential of BISC to transform the cerebral cortex into a high-bandwidth interface was further elaborated upon by Andreas S. Tolias, PhD, professor at the Byers Eye Institute at Stanford University and co-founding director of the Enigma Project. Tolias, whose extensive experience in training AI systems on large-scale neural recordings, including those captured by BISC, proved instrumental in assessing the implant’s decoding capabilities, stated, "BISC turns the cortical surface into an effective portal, delivering high-bandwidth, minimally invasive read-write communication with AI and external devices. Its single-chip scalability paves the way for adaptive neuroprosthetics and brain-AI interfaces to treat many neuropsychiatric disorders, such as epilepsy." This underscores BISC’s versatility, extending beyond mere data acquisition to active modulation and interaction.
Dr. Brett Youngerman, an assistant professor of neurological surgery at Columbia University and a neurosurgeon at NewYork-Presbyterian/Columbia University Irving Medical Center, served as the project’s primary clinical collaborator. His perspective emphasizes the profound clinical implications of this advancement. "This high-resolution, high-data-throughput device has the potential to revolutionize the management of neurological conditions from epilepsy to paralysis," Dr. Youngerman asserted. He, along with Shepard and Dr. Catherine Schevon, an epilepsy neurologist at NewYork-Presbyterian/Columbia, have already secured a National Institutes of Health grant to explore BISC’s efficacy in treating drug-resistant epilepsy. Dr. Youngerman further elaborated on the critical design principles: "The key to effective brain-computer interface devices is to maximize the information flow to and from the brain, while making the device as minimally invasive in its surgical implantation as possible. BISC surpasses previous technology on both fronts."
Shepard attributed the realization of such advanced miniaturization to the rapid progress in semiconductor technology. "Semiconductor technology has made this possible, allowing the computing power of room-sized computers to now fit in your pocket," he remarked. "We are now doing the same for medical implantables, allowing complex electronics to exist in the body while taking up almost no space." This statement encapsulates the paradigm shift BISC represents in implantable medical devices.
The engineering behind BISC represents a significant leap forward in next-generation BCI design. Traditional medical-grade BCIs typically employ multiple discrete microelectronic components, including amplifiers, data converters, and radio transmitters. These components necessitate a substantial implanted canister, often requiring extensive surgical procedures to implant, either by removing a portion of the skull or placing it elsewhere in the body, with wires then extending to the brain.
BISC’s architecture fundamentally redefines this approach. The entire system is integrated onto a single complementary metal-oxide-semiconductor (CMOS) integrated circuit. This chip has been meticulously thinned to a mere 50 micrometers, occupying less than 1/1000th the volume of a conventional implant. With an astonishingly small footprint of approximately 3 mm³, the flexible chip is engineered to conform to the contours of the brain’s surface. This micro-electrocorticography (µECoG) device boasts an impressive array of 65,536 electrodes, enabling 1,024 recording channels and 1,024 stimulation channels. Crucially, the chip’s production utilizing established semiconductor industry manufacturing methods ensures its suitability for scalable, cost-effective mass production.
The integrated chip ingeniously incorporates a radio transceiver, a wireless power circuit, digital control electronics, power management systems, data converters, and the analog components essential for both recording and stimulating neural activity. The external relay station serves as a vital hub, providing both power and data communication through a custom ultrawideband radio link capable of achieving a remarkable 100 Mbps throughput. This data transfer rate is at least 100 times faster than any other wireless BCI currently available. Operating seamlessly as an 802.11 WiFi device, the relay station acts as a conduit, bridging the implant to any standard computer.
BISC is not merely a hardware marvel; it also features its own dedicated instruction set and a comprehensive software environment, forming a specialized computing system tailored for brain interfaces. The high-bandwidth recording capabilities demonstrated in the study are pivotal, allowing for the processing of brain signals by advanced machine-learning and deep-learning algorithms. These sophisticated algorithms are capable of interpreting complex intentions, perceptual experiences, and nuanced brain states with unprecedented accuracy. "By integrating everything on one piece of silicon, we’ve shown how brain interfaces can become smaller, safer, and dramatically more powerful," Shepard emphasized, underscoring the synergistic benefits of this integrated design.
The advanced semiconductor fabrication techniques employed were critical to BISC’s development. The implant was manufactured using TSMC’s 0.13-µm Bipolar-CMOS-DMOS (BCD) technology. This sophisticated fabrication method merges three distinct semiconductor technologies into a single chip, enabling the creation of mixed-signal integrated circuits (ICs). This integration allows for the efficient co-existence of digital logic (from CMOS), high-current and high-voltage analog functions (from bipolar and DMOS transistors), and power devices (from DMOS), all of which are indispensable for BISC’s exceptional performance.
The journey from laboratory innovation to clinical application is a critical phase, and Shepard’s team has made significant strides in this direction. They have partnered with Dr. Youngerman at NewYork-Presbyterian/Columbia University Irving Medical Center to develop refined surgical procedures for the safe implantation of the thin device in preclinical models. These efforts have yielded confirmation of the device’s ability to produce high-quality, stable neural recordings. Furthermore, short-term intraoperative studies in human patients are already in progress, marking a pivotal step towards real-world clinical integration.
"These initial studies give us invaluable data about how the device performs in a real surgical setting," Dr. Youngerman stated. He detailed the surgical advantages: "The implants can be inserted through a minimally invasive incision in the skull and slid directly onto the surface of the brain in the subdural space. The paper-thin form factor and lack of brain-penetrating electrodes or wires tethering the implant to the skull minimize tissue reactivity and signal degradation over time." This minimally invasive approach is paramount for patient safety and long-term efficacy.
Extensive preclinical work, focusing on the motor and visual cortices, was conducted in collaboration with Dr. Tolias and Bijan Pesaran, professor of neurosurgery at the University of Pennsylvania. Both are recognized leaders in the fields of computational and systems neuroscience, lending their considerable expertise to validate BISC’s capabilities. "The extreme miniaturization by BISC is very exciting as a platform for new generations of implantable technologies that also interface with the brain with other modalities such as light and sound," Pesaran commented, hinting at future synergistic integrations.
The development of BISC was supported by the Neural Engineering System Design program of the Defense Advanced Research Projects Agency (DARPA). It stands as a testament to Columbia’s profound expertise in microelectronics, the cutting-edge neuroscience programs at Stanford and Penn, and the advanced surgical capabilities of NewYork-Presbyterian/Columbia University Irving Medical Center.
To accelerate the transition of this technology into practical medical use, researchers from Columbia and Stanford have founded Kampto Neurotech. This startup, established by Dr. Nanyu Zeng, a Columbia electrical engineering alumnus and one of the project’s lead engineers, is actively producing research-ready versions of the chip and is focused on securing the necessary funding to prepare the system for human clinical trials. "This is a fundamentally different way of building BCI devices," Zeng remarked. "In this way, BISC has technological capabilities that exceed those of competing devices by many orders of magnitude."
As artificial intelligence continues its rapid advancement, brain-computer interfaces are experiencing a surge in momentum. This is driven by their dual potential: restoring lost abilities in individuals with neurological disorders and exploring future applications that could enhance normal human function through direct brain-to-computer communication. "By combining ultra-high resolution neural recording with fully wireless operation, and pairing that with advanced decoding and stimulation algorithms, we are moving toward a future where the brain and AI systems can interact seamlessly — not just for research, but for human benefit," Shepard concluded with optimism. "This could change how we treat brain disorders, how we interface with machines, and ultimately how humans engage with AI." The advent of BISC heralds a new era, where the boundaries between the human mind and artificial intelligence are poised to blur, promising profound benefits for both health and human potential.
