Site Density
Site density is the number of electrode sites per square millimeter of the site footprint; for the same site count, high density samples a small region finely and low density covers a broad region sparsely.
It is site count divided by site footprint, so it summarizes pitch in both directions in one number.
Density is the axis on which a tetrode and a linear probe with the same 32 sites sit at opposite ends. Sites packed at 20 to 25 µm inside the detection radius see the same neurons from several positions — the high-density end, where the gain is unit isolation, not reach. Sites at 100 or 200 µm each see their own neurons — the low-density end, where the gain is coverage. Because a two-dimensional density overstates the density of a single-shank design whose footprint is nearly a line, brain coverage density is the version to use when comparing across shank counts. In the catalog, site density is the parameter most often named alongside site count when a design is described as high-density.
Typical values
| Catalog silicon probes | about 2 to 2,800 sites/mm²; about 260 is the median |
|---|---|
| Definition | site count ÷ site footprint |
| Design-space parameter | Site density (siteDensityPerMm2) |