Microwire Arrays (MWAs)* are most commonly used in chronic, freely moving animal studies. They are easily customizable, well-constructed, and appropriate for large and small animals. MWAs are popular due to both their recording reliability and cost efficiency. Additionally, they are compatible with any Plexon headstages that utilize Omnetics connectors.
MWAs can be customized in many ways with choices for electrode number, configuration, spacing, materials, insulation, lengths, diameter, and connectors amongst other options. The wires are crafted using stainless steel or a platinum/iridium alloy to be durable; yet, cost effective enough to be disposable. Dissolvable polyethylene glycol (PEG) secures the wires’ spatial arrangement, which ensures the electrodes remain straight and maintain their parallel position within the array while advanced into the tissue. This stability in design is particularly important when targeting deep brain structures. All MWAs come with optional ground and low-impendence reference wires that, when used with Plexon headstages and preamplifiers, assist with common-mode rejection and removal of artifacts.
To enhance your experience, control and results when using MWAs, we offer a breadth of compatible, high quality connectors, headstages, headstage cables, and commutators. You may also wish to explore other options in Plexon’s family of specialty electrodes, probes and arrays including the Floating Microelectrode Array, U-Probe, or the advanced Thumbtack Probe.
This made-to-order MWA is the standard choice for hundreds of research labs around the world performing chronic, freely moving animal studies. Your Plexon Sales Engineer is happy to provide additional information and to assist you in determining what might be the most advantageous MWA configurations to achieve the most from your research.
MWAs are extremely customizable, as can be seen in the table below. It may be possible to produce arrays outside the listed specifications. Discuss your needs with a Plexon Sales Engineer to determine the best configuration and if your unique request can be accommodated.
The image to the right should assist in clarifying certain dimensions discussed.
|Feature||Specifications and Options||Remarks|
|Applications||In vivo; chronic or acute|
|Wire material||Stainless steel or platinum/iridium||Stainless steel is most typical.|
|Wire insulation||Polyimide or Teflon||Polyimide is the most typical.|
|Wire diameter||25 or 50μm||50μm is the most typical.|
|Impedance||Stainless steel wire:|
– 25μm is 0.6 to 0.9MΩ
– 50μm is 0.4 to 0.6MΩ
– 25μm is 0.4 to 0.8MΩ
– 50μm is 0.2 to 0.4MΩ
|Impedance provided is per-wire.|
|Electrodes||4 to 32|
|Electrode spacing||Available in increments of 250μm, beginning with 250μm||The tightest arrangements of 250 and 500μm are most typical.|
|Electrode configurations||2×4, 4×4, 2×8, 4×8, etc.||Configurations are limited only by the total number of electrodes requested.|
|Rows||1 to 12|
|Row spacing||Available in increments of 250μm, beginning with 250μm||The tightest arrangement of 250μm is most typical.|
|Connectors||1 to 6|
|Connector type||Any Omnetics connector that is compatible with any Plexon headstage||For more information, see the connectors or headstages pages.|
|Reference wire||Available, but optional||Reference wire material is typically the same as the electrode wire material.|
|Ground wire||Available in stainless steel or silver||Stainless steel ground wires have a diameter of 100μm while silver wires have a 125μm diameter.|
|Ground wire length||80mm||Custom lengths available, however 80mm is recommended for achieving a solid attachment to the skull screw.|
|Ground wire positioning||Extends from the base of the connector||Custom positioning is available, however extending from the base of the connector is the default.|
|Epoxy length||3 to 5mm||3mm is most typical for 0.025” pitch connectors, while 5mm is most typical for connectors with an 0.050” pitch.|
|Length of wire enveloped in PEG||1 to 23mm||5mm is most typical. PEG provides temporary stability, ensuring the electrodes remain straight as well as maintain their position within the array while being advanced into the tissue. The PEG is easily dissolved during the insertion process by gently ﬂushing it with saline, performed most often near the insertion site.|
|Length of wire exposed beyond PEG||1 to 10mm||2mm is most commonly requested.|
*MWAs are manufactured by MicroProbes for Life Sciences.