Silicon Probe
A silicon probe is a microelectrode array intended as a microscale neural interface for recording and/or microstimulation.
It has one or more thin silicon shanks with discrete electrode sites at lithographically defined positions. Each site forms an electrochemical interface with tissue at a known depth and lateral offset, recording extracellular potentials or electrical microstimulation.
Silicon probes are made by thin-film microfabrication: conductive and insulating layers deposited on a silicon substrate and patterned by photolithography, which reproduces fine-feature geometry with sub-micron precision wafer to wafer. The mask set fixes the probe geometry — shank width and length, site area, and the spatial layout of sites along the shank — so probe geometry is established at fabrication rather than at assembly and is precise and invariant within a design.
Micro-scale neural interfaces are not one size fits all; function follows fit. NeuroNexus has a large electrode design space, and precision and reproducibility let a geometry be designed against a specific neural target or application. The electrode catalog holds 216 designs: 4 to 1,024 sites, 1 to 16 shanks, 1.5 to 60 mm, on a 15 or 50 µm substrate.
Probe quality is the product of the microfabrication process, the design details, and the package assembly. Silicon probes are designed to penetrate the brain, spinal cord, nerves, ganglia or heart; their surface counterparts are thin-film grids. Research use only.
Typical values
| Catalog designs | 216, in 10 families |
|---|---|
| Sites per probe | 4 to 1,024 |
| Shanks | 1 to 16 |
| Shank length | 1.5 to 60 mm |
| Site area | 92 to 1,250 µm² |
| Substrate thickness | 15 or 50 µm |
| Site metal | iridium (209 designs); platinum (3) |