The Layer 7 Cortical Interface is Precision Neuroscience's flagship BCI device — a high-density thin-film ECoG array that records from the cortical surface without penetrating brain tissue. With 1,024 electrodes on a flexible substrate just 20 micrometers thick, Layer 7 represents the state of the art in surface electrode technology and offers a potentially less invasive alternative to penetrating arrays like the Utah Array and Neuralink N1.

Design

  • Electrode count: 1,024 channels arranged in a high-density grid
  • Thickness: 20 micrometers (approximately the width of the thinnest human hair)
  • Substrate: Flexible thin-film polymer (polyimide)
  • Electrode material: Platinum or platinum-iridium contacts
  • Delivery: Inserted through a thin slit craniotomy using a proprietary delivery tool — no large craniotomy required
  • Conformability: The array conforms to the curved cortical surface, maximizing electrode-tissue contact

Advantages

Layer 7 occupies a strategic position in the BCI device landscape:

  • No tissue penetration: Unlike intracortical arrays, Layer 7 sits on the cortical surface without entering brain tissue, potentially reducing foreign body response, glial scarring, and neuronal damage
  • High channel count: 1,024 channels matches Neuralink's N1 while using a fundamentally different recording modality (surface ECoG vs. intracortical)
  • Minimal craniotomy: The thin, flexible array can be inserted through a linear slit rather than a large circular craniotomy
  • High-gamma access: ECoG recordings capture high-gamma activity (70-150 Hz), which carries information about local cortical processing that scalp EEG cannot detect

Signal Characteristics

ECoG signals from Layer 7 differ from intracortical recordings:

  • No single units (typically): Surface electrodes generally cannot isolate individual neuron action potentials, though Precision has reported single-unit detection in some electrodes
  • Rich LFP and high-gamma: Broadband power features, particularly high gamma, are the primary decodable signals
  • Potentially more stable: Without tissue penetration, the device may avoid the progressive signal degradation caused by glial scarring of intracortical electrodes

Clinical Status

As of early 2026, Precision Neuroscience has conducted intraoperative recordings with Layer 7 in multiple neurosurgical patients (acute recordings during surgery, array removed at end of procedure). The company is pursuing FDA IDE authorization for chronic implantation studies. The long-term performance of a chronically implanted Layer 7 array in humans has not yet been demonstrated.