Sources and simplifications

Schematic, not to scale where noted:

  • Tissue layer thicknesses are typical adult values (scalp ~5 mm, skull ~7 mm, dura ~1 mm, cortex ~3 mm), not a patient's.
  • 16 of the 64 threads are drawn, each as one line with one recording neuron; real threads carry 16 electrodes each.
  • Threads, needle and neurons are drawn about 10–40× thicker than they are; a 24 µm needle would be invisible at this scale.
  • The implant's inside (battery, coil, board, chips) is a schematic layout; Neuralink has not published one.
  • Thread depth and routing are schematic. The cursor decoder is a textbook population-vector sketch, not Neuralink's decoder.
  • Spikes are slowed for visibility.

Sources:

The implant's chips: spikes detected on the implantSection through scalp, skull, dura and cortex16 of the 64 threads, each to one neuronThe Neuralink N1 implant, as a three.js scene cut through the head on one plane. The implant is 23 mm across and 8 mm tall [3]. It records from 1024 electrodes on 64 flexible threads [1], each thread 5–50 µm wide and 4–6 µm thick [4]. Step through it. A flap of scalp is folded back and a disc of bone is removed (a craniectomy). The R1 robot pushes each thread into the cortex on a tungsten-rhenium needle etched to 24 µm [4], aiming between the surface vessels. The 2019 system could insert up to 6 threads a minute [4]. The implant then takes the bone's place in the opening, and the skin is closed over the implant, which cannot be seen from outside [1]. When a neuron fires, the electrode next to it picks up the spike. Chips in the implant band-pass the signal (500 Hz–5 kHz), set an adaptive threshold for each channel and detect spikes, which are often under 20 µV. Only the spikes are sent on, which is how the whole system runs on about 32 mW [5]. They go over Bluetooth [6] to the app, which decodes them into cursor movement [2]. A battery inside is recharged through the scalp by an inductive charger [2]. The 3D view uses a section plane that clips the implant, bone and vessels and hatches their cut faces. The grey matter is shaded with vertex colours, the spikes and radio packets glow with a shader, and the implant's board carries a procedural texture. The step-3 thread count shows 16 because only 16 of the 64 threads are drawn. Simplifications and sources are listed below.