SiNAPS: Active High-Density Microelectrodes
SiNAPS probes put an active pixel under each of 256 to 1,024 sites, so a thousand channels on a 5 mm shank read out as data. The designs and the costs.
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Updated October 12, 2026
A SiNAPS probe has an active pixel under each electrode. Amplification, low-pass filtering and 32:1 multiplexing all sit on the shank, so the signal is converted where it is recorded rather than carried out as an analog trace. That is what makes a thousand channels on a 5 mm shank tractable: the cable carries data, not a thousand analog lines. The family is explained once in HD Series ↗.
Research use only. NeuroNexus products and the procedures described here are for non-clinical research use, and must not be used in human or veterinary medical procedures.
The three catalog designs#
Geometry below is derived from the probe descriptors, not quoted from a datasheet.
| channels | shanks | shank length | site pitch | active length | |
|---|---|---|---|---|---|
| SiNAPS 1S-256 | 256 | 1 | 5.5 mm | 29.6 µm | 3,754 µm |
| SiNAPS 4S-1024 | 1,024 | 4, at 560 µm | 5.5 mm | 29.6 µm | 3,754 µm per shank |
| SiNAPS 8S-1024 | 1,024 | 8, at 300 µm | 5.0 mm | 30.3 µm | 1,911 µm per shank |
Sites are 14 × 14 µm on 50 µm silicon. Every site is read at 20 kHz, and the noise floor is 6.5 µVrms from 300 to 7,500 Hz. Shank separations are center-to-center.
The decision between them#
The two 1,024-channel designs are the same channel budget spent differently. 4S-1024 puts 3,754 µm of active length on each of four shanks 560 µm apart — depth coverage, with lateral sampling wide enough to cross a boundary. 8S-1024 halves the active length to 1,911 µm and puts eight shanks 300 µm apart — a denser lateral map over a shorter depth span.
So the question is not which is higher density; both are 1,024 channels at ~30 µm pitch. It is whether your structure is deep and you need to cross it, or shallow and you need to map across it.
1S-256 is the single-shank case, and it is the one to use when a second shank would be a second penetration you cannot afford.
What active-pixel costs you#
It is record-only. There is no stimulation path through an active-pixel array. A protocol that needs both high site counts and current delivery has to solve that with different hardware — see NeuroNexus Data Acquisition Systems: Platform Overview.
Calibration comes first and is not optional. Unlike a passive array, the per-pixel electronics have to be calibrated before the array means anything. The step is in the SiNAPS Manual.
The data rate is a project constraint. 1,024 channels at 20 kHz is about 41 MB/s, or 1.18 TB in an eight-hour session. Plan storage with the probes — see High-Density Recording: A Planning Guide.
Which experiments SiNAPS is for#
SiNAPS is chosen when the question is a population, not a handful of units: how a thousand neurons across a structure coordinate during a behavior, how activity flows across cortical layers and columns at once, how a circuit's state changes over a session. At about 30 µm pitch every neuron within the detection radius ↗ of the shank appears on several sites, so the spatial oversampling a spike sorter ↗ needs is built into the geometry, and the yield per penetration is set by the tissue rather than by the electrode. The 14 × 14 µm platinum sites are the smallest in the catalog and read as small sites do — local, with a higher impedance and noise floor than a 177 µm² site, which the on-shank amplifier is placed millimeters from the site to manage.
It is not the choice for a study that needs stimulation, a chronic implant where the acquisition path cannot be carried, or a target where a 50 µm substrate and a 5 mm shank do not fit. For those, the passive high-density designs — a 64-site polytrode at 25 µm, an 8-shank Buzsaki at 256 sites — reach a few hundred channels through a conventional package ↗ and headstage, with stimulation and chronic packages available. The comparison across the catalog is in Choosing an Electrode for Your Experiment.
Acquisition#
Smartbox is the acquisition path for SiNAPS, carrying 1,024+ channels over the SiNAPS interface at the probe's fixed 20 kHz. XDAQ with Radiens is the path when SiNAPS runs alongside passive arrays, grids or Neuropixels in the same workspace.