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MEA Layouts

A microelectrode array (MEA) consists of 3 parts:

  • Contact Pads: Metal pads for interconnection to a printed circuit board (PCB)
  • Ribbon Cable: Region containing electrical traces connecting contact pads to microelectrode sites
  • Implanted Probes: Implanted region having penetrating shanks containing traces and microelectrode sites

Our library of different polymer MEAs (pMEAs) are available for download here. Different designs were customized for use in mice, rats, and non-human primates (NHP). The mice and NHP pMEAs are considered two dimensional (2D) as they are planar devices that possess multiple sites to access multiple sites in a single plane of the brain. The rat devices are intended to be used in a paired and stacked arrangement and are considered three dimensional (3D) pMEAs. These 3D pMEAs access multiple sites along different planes. The MEA design files can be used with KLayout (https://www.klayout.de/) which is an open-source mask layout software. Also included are the original AutoCAD design files.

This page contains the layout and design files for each pMEA, accessible through links in each section. We also include the PCB files for each design. Our PCBs are designed for use with standard Omnetics connectors and can be modified to fit other connector styles. The PCB files can be used with KiCad (https://www.kicad.org/) which is an open-source PCB design software.

In addition, we also include a version of a sample pMEA design to be integrated with a bare of packaged application specific integrated circuit (ASIC). This this case, we have chosen a commercially available device (Intan RHD2164) but the layout can be adapted to accommodate a different chip. The design files were originally created in Altium but included here in an open-source format that can be accessed using KiCad.

We will continue to upload new designs as they become available.

Mice Designs

We designed two pMEAs for mice
We designed two pMEAs for the mouse that target sub-regions of the hippocampus. Design A targets CA1 and CA3 along the anterior-posterior axis, while Design B conforms to the cell body layers on a coronal hippocampal plane to target CA1, CA3, and DG.

Downloadable Zip Files (MEAs and PCB) :

Mice Files_v1
Mice Design A_Files v2
Mice Design B Files_v2

Rat Design A

In Rat Design A, two linear arrays are stacked at a fixed distance apart (1500 µm) to create a 3D pMEA with 2 x 4 shanks that can target different regions of the hippocampus, including CA1, CA3, and DG. A single layer consisting of a 4-shank linear array is shown above.
The above PCB design is associated with the version 1 design.
The above PCB design is associated with the version 2 design and includes a spacer board (red “daughter” board) that is bonded to the underlying green “mother” board. The holes in the board at the corners allow for alignment pins to be inserted to guide assembly.

Downloadable Zip Files (MEAs and PCB)

Rat Design A Files_v1
Rat Design A Files_v2

Rat Design B

In Design B for rat, there are four two-shank linear arrays, each array having 32 channels. Pairs of mirrored two-shank arrays are placed back-to-back, as shown above, so that electrode sites are on both sides of the shank. The paired MEAs are then arranged with 1500 µm spacing. This configuration targets the CA1, CA3, and DG regions. The back-to-back designs are split into base and top layers. Layers are aligned using alignment holes that are directly incorporated into the Parylene substrate and matching pins that are designed into the PCB.

Downloadable Zip Files (MEAs and PCB)

Rat Design B Files_v1
Rat Design B Files_v2

Nonhuman Primate

We designed two single-shank pMEAs for nonhuman primate (NHP) capable of targeting the cortex in the version 1 files. New single and multi-shank pMEA designs were added in version 2.

Downloadable Zip Files (MEAs)

NHP Files_v1
NHP Single Shank Files_v2
NHP Multi-Shank Files_v2

Chip-Integrated pMEA

The pMEA with an integrated Intan RHD2164 was achieved using the polymer ultrasonic bump (PUB) bonding technique. The development of the PUB bonding technique is described in this journal paper: (1) link to publisher’s page and (2) PubMed page. ASIC integration results were described in this conference paper: link. Downloadable protocols for the integration and PUB bonding method are available on our resources page.

Downloadable Zip File

Chip Integrated pMEA Files

Terms of Use: These works are licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0). They are attributed to members of the Biomedical Microsystems Laboratory (directed by Ellis Meng) and the Neural Modeling and Interface Laboratory (directed by Dong Song).

Updated 10/1/2024.

University of Southern California