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    Utah array

    Also known as Utah Intracortical Electrode Array, UIEA, microelectrode array

    The Utah array is a small grid of needle-like microelectrodes that penetrates the cortex and records from small groups of neurons; it was described as a recording structure for brain-computer interfaces in 1997.[1] Arrays of this kind underpin most academic BCI milestones, including the 2006 BrainGate cursor study and the 2024 UC Davis speech neuroprosthesis that used four arrays with 256 electrodes.[2][3]

    Editor reviewedStrict sourcingUpdated Neuroscience and brain-computer interfacesHealth and medicineLife sciences
    Key facts

    What it is

    The Utah Intracortical Electrode Array is a grid of microelectrodes that is pushed into the surface of the cortex. A 1997 study described it as a recording structure for brain-computer interfaces. It found that the array records from small populations of neurons with an average signal-to-noise ratio of 6 to 1, and that these population signals carry enough information for control tasks.[1]

    The 1997 authors concluded that recordings from small populations of neurons, rather than single cells, are a reliable signal source for a BCI, and that an array of microelectrodes could in principle support simultaneous control of many devices.[4]

    Landmark uses

    Cursor and hand control (2006). A man with tetraplegia used a 96-electrode array in his primary motor cortex to move a “neural cursor”, open simulated e-mail, operate a television and open and close a prosthetic hand. Recordings showed that intended hand movement still shaped cortical activity three years after his spinal cord injury.[2]

    Robotic arm (2012). Two people with long-standing tetraplegia used signals from a 96-channel array in motor cortex to steer a robotic arm through three-dimensional reach and grasp movements. One participant, implanted five years earlier, used it to drink coffee from a bottle.[5]

    Handwriting (2021). A Stanford participant whose hand was paralysed by spinal cord injury imagined writing letters, and a neural-network decoder turned the activity into text at 90 characters per minute with 94.1 percent raw accuracy. That is close to the 115 characters per minute typical of smartphone typing for people his age.[6]

    Speech to text (2023). A Stanford team decoded attempted speech from intracortical arrays in a participant with ALS at 62 words per minute, with a 23.8 percent word error rate on a 125,000-word vocabulary.[7]

    Accurate conversation (2024). UC Davis surgeons placed four arrays with 256 electrodes in a man with ALS. The system held 97.5 percent accuracy over 8.4 months and he used it for more than 248 hours of conversation.[3][8] The work ran within the long-running BrainGate2 trial.[9]

    Voice synthesis (2025). A 2025 UC Davis study used 256 implanted microelectrodes in a man with ALS to drive a real-time voice synthesizer that could change intonation and sing short melodies.[10]

    Industry

    Blackrock Neurotech, a BCI company, says its technology has let patients type up to 90 characters per minute and decode up to 62 words per minute.[11] Those figures match the academic handwriting and speech studies described above.[6][7] The newer companies take different approaches: Neuralink uses flexible threads inserted by a robot, and Paradromics uses a dense array of 421 microelectrodes.[12][13] Speech-decoding intellectual property from Stanford has been licensed to Blackrock Neurotech and Neuralink, according to a 2025 paper’s disclosures.[14]

    Limits

    Speech systems have used several arrays at once; the UC Davis system used four.[3] The arrays are placed during brain surgery, and surgical risk is why implant trials enrol only people with severe disabilities.[15] Newer approaches aim to record more neurons with denser probes such as Neuropixels, or to avoid penetration with surface films like Precision Neuroscience‘s Layer 7.[16][17]

    Questions readers ask

    What does a Utah array record?

    Small populations of neurons near its electrode tips, rather than single cells or whole-brain activity. A 1997 study measured an average signal-to-noise ratio of 6 to 1.[1]

    What have people done with Utah arrays?

    Moved a computer cursor and operated a prosthetic hand in 2006, and in 2023 and 2024 turned attempted speech into text at up to 62 words per minute or with 97.5 percent accuracy.[2][7][8]

    Which companies work with this kind of array?

    Blackrock Neurotech says its technology has let patients decode up to 62 words per minute, and Stanford speech-decoding intellectual property has been licensed to Blackrock Neurotech and Neuralink.[11][14]

    Sources

    Each numbered claim is a statement we checked against the sources listed with it. Status shows how well established it is.

    1. [1]

      A 1997 study described the Utah Intracortical Electrode Array as a recording structure for brain-computer interfaces, recording from small populations of neurons with an average signal-to-noise ratio of 6 to 1. confirmedas of 1997-03-01

    2. [2]

      In a 2006 Nature study, a man with tetraplegia used a 96-microelectrode array implanted in his primary motor cortex to move a computer cursor, open simulated e-mail and operate a prosthetic hand. confirmedas of 2006-07-13

    3. [3]

      In the UC Davis speech neuroprosthesis study, a 45-year-old man with ALS received four microelectrode arrays with 256 electrodes in his left ventral precentral gyrus. confirmedas of 2024-08-15

    4. [4]

      The 1997 Utah array study concluded that recordings from small populations of neurons, rather than single units, provide reliable signals suitable for a BCI, and that arrays could support control of many devices at once. confirmedas of 1997-03-01

    5. [5]

      In 2012 two people with long-standing tetraplegia used signals from a 96-channel motor cortex array to control a robotic arm for three-dimensional reach and grasp, and one, implanted five years earlier, drank coffee from a bottle with it. confirmedas of 2012-05-16

    6. [6]

      In a 2021 Stanford study, a participant whose hand was paralysed by spinal cord injury used an intracortical BCI that decoded attempted handwriting to type 90 characters per minute with 94.1% raw accuracy, close to typical smartphone typing speeds for his age group (115 characters per minute). confirmedas of 2021-05-12

    7. [7]

      A 2023 Stanford study decoded the attempted speech of a participant with ALS from intracortical arrays at 62 words per minute, with word error rates of 9.1 percent on a 50-word vocabulary and 23.8 percent on a 125,000-word vocabulary, and found a detailed articulatory representation of phonemes persisting years after paralysis. confirmedas of 2023-08-23

    8. [8]

      The UC Davis neuroprosthesis reached 99.6 percent accuracy on a 50-word vocabulary on its first day of use and sustained 97.5 percent accuracy over 8.4 months, with the participant conversing at about 32 words per minute for more than 248 hours. confirmedas of 2024-08-15

    9. [9]

      The UC Davis speech study was part of the BrainGate2 clinical trial (NCT00912041). confirmedas of 2024-08-15

    10. [10]

      A 2025 UC Davis study synthesized a man's voice in real time from 256 implanted microelectrodes, and let him change intonation and sing short melodies. confirmedas of 2025-06-12

    11. [11]

      Blackrock Neurotech, which makes Utah-array-based systems, says its technology has let patients type up to 90 characters per minute and decode up to 62 words per minute. confirmedas of 2026-10-10

    12. [13]

      The Connexus BCI uses 421 microelectrodes that reach 1.5 millimetres below the brain's surface to record individual neurons, with a transceiver in the chest that transmits data wirelessly through the skin. confirmedas of 2026-10-10

    13. [14]

      According to the competing-interest disclosures of a 2025 Nature paper, Stanford University speech-decoding intellectual property has been licensed to Blackrock Neurotech and Neuralink, and University of California speech-BCI intellectual property has been licensed to Paradromics. confirmedas of 2025-06-12

    14. [15]

      The risks of brain surgery currently limit participation in implantable BCI clinical trials to people with severe disabilities. confirmedas of 2024-12-17

    15. [16]

      A 2022 study used a Neuropixels probe variant to record more than 200 well-isolated single neurons at once in human cortex during neurosurgery. confirmedas of 2022-02-01

    16. [17]

      Layer 7 is a thin-film surface electrode array with 1,024 electrodes on a device about the size of a postage stamp. confirmedas of 2026-10-10

    Revision history (2)
    1. Page created.
    2. Refresh: added the 2012 robotic-arm and 2021 handwriting studies and a comparison with newer company devices.

    Created Oct 10, 2026. Last reviewed by an editor on Oct 10, 2026. Next scheduled review: Jan 10, 2027.

    Cite this page

    "Utah array." ContentLora, updated Oct 10, 2026. https://contentlora.com/wiki/utah-array

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