Single, Bipolar & Concentric Electrodes, Nerve Cuff
WPI offers a broad variety of standard and custom single monopolar, concentric, and stereotrode designs in a variety of tip profile and metal combinations. Some of these electrodes are also available with Rhodes style tips.
WPI offers a large variety of electrodes.
For more informations, see FAQs about Metal Microelectrodes
- Concentric bipolar electrodes are excellent for shielded macro recording, as well as evoked potentials. They are especially well suited for bipolar stimulation. The tungsten electrode is sharpened to a point and is 75μm in diameter. The outer stainless steel conductor is insulated with Polyimide tubing to within 0.2mm of the end of the stainless steel tube. This electrode is also available without the outer Polyimide insulation. A comparison of the concentric electrodes is at the bottom of the page. Concentric electrodes with outer polyimide insulation Concentric electrodes without insulation This figure shows an insulated metal conductor with an exposed concentric surface.
- Each of these assortment kits includes electrodes with different impedance within each style. Use an assortment kit to determine which electrode you need for your experiment. Each box includes the electrodes listed. There are no mix and match assortment kits. A comparison of the assortment electrode kits is at the bottom of the page. Profile A Profile B Profile C
- Dri-Ref™ reference electrodes were developed by WPI to have extremely low electrolyte leakage properties. In addition to this key feature, these electrodes exhibit stable and reproducible potential and low resistance. Stored in KCl when not in use, they have a long life expectancy. Although the internal filling solution contains KCI, the low fluid leakage means Dri-Ref may be used in combination with ion selective electrodes, including those for K+ and Cl-, without significant contamination from the reference electrode. The Dri-Ref electrodes are chemically resistant to strong acids and alkalines. Dri-Ref electrodes are not suitable for use in organic solvents. In addition, the long, thin FLEXREF may be easily manipulated to accommodate a difficult experimental setup.
- Elgiloy stainless is a stainless steel alloy with excellent corrosion resistance and high tensile strength. A comparison of the Elgiloy Stainless electrodes is at the bottom of the page. Profile A Profile C
- Our nerve cuff electrodes can be built to your specifications. See all the options you can choose.
- Platinum iridium profile A electrodes are sold in packages of 10. Profile A metal electrodes look like the image below. A comparison of the platinum iridium profile A electrodes is at the bottom of the page.
- Profile C metal electrodes look like the image below.
- The pure iridium metal electrodes are used for multi unit and single unit recording and stimulation. Profile A Profile C
- These Concentric Bipolar Electrodes with Rhodes style tips are designed for Neurological recording and stimulation and are ideal for acute applications (without the X) or chronic applications (ends with X). The Stainless Steel external tubing (E) provides support for accurate placement. The extra extension may be cut off after insertion leaving only a small protrusion. Features Rhodes-style tips are great for those that require a precisely controlled electrode surface area The Stainless Steel external tubing provides support for accurate placement and manipulation during acute research These are an excellent replacement for long-term Rhodes electrodes (originally made by Kopf) Benefits Concentric bipolar electrodes are ideal for bipolar stimulation paradigms Tools are available for shielded macro recordings, as well as evoked potential Electrodes may be acutely reused many times (> 20-30 insertions), if they are properly cared for: Avoid bending the shaft and blunting/hooking the tip Clean electrode carefully between session Applications Designed for Neurological recording and stimulation and are ideal for chronic applications.
- Surface electrodes come in a variety of shapes and sizes. They include silver-silver chloride pellets. We also have dry reference electrodes.
- Tungsten profile A electrodes can be used for recording or stimulation. Profile A metal electrodes look like the image below. A comparison of the tungsten profile A electrodes is at the bottom of the page.
- Tungsten profile B electrodes are stereotrode, bipolar electrodes. They are used for making differential measurements and extra fine recording. Profile B metal electrodes look like the image below. A comparison of the tungsten profile B electrodes is at the bottom of the page.
- Tungsten profile C electrodes can be used for recording or stimulation. Profile C metal electrodes look like the image below. A comparison of the tungsten profile C electrodes is at the bottom of the page.
- Many standard types available (web) and custom
- Connecting pin fits Amphenol series 220-223 connectors
- Type C: Excellent for bipolar stimulation
- For acute and chronic recording
- Heat treated electrodes used for penetrating tough membrane (not for chronic implantation)
For basic information on these types of metal electrodes, click here to see the Metal Microelectrode Basics page.
For a table with specifications for the various electrodes, use the links below:
Kapton Coating on Electrodes
Kapton* tubing, indicated by “KT” in the part number, extends from the connector to within 5mm of the tip, providing stiffness and additional insulation to the electrode shaft. Kapton-clad electrodes are recommended when the electrode is to be inserted through a cannula for extra deep penetration.
Heat Treating Electrode Tips
The Heat Treated Tip (see image below) is ideal for penetrating tough membranes. (It is not recommended for chronic implantation.) This process is performed using a microforge in which the heating element is positioned in close proximity to the tip in order to melt the Parylene-C distal to the exposed metal. It provides a smooth transition and produces better adherence of the Parylene-C to the metal.
Both the KT and non-KT electrodes are heat-treatable. The heat treatment is applied only to the parylene coating. The heat melts the paryleneso it feathers down close to the shank near where the tip is exposed. This removes the abrupt edge where the parylene has been removed tocreate the tip exposure. The purpose is to prevent the parylene from delaminating from the electrode during implantation into tissue which couldcatch on the edge. Heat treatment does not work well in chronic applications, because the feather edge is susceptible to fluid intrusion overtime, which will alter the impedance characteristics of the electrode unfavorably.
To have your electrodes heat treated, just add the suffix “H” to any of the “KT” numbers on the facing page. This treatment incurs an additional cost. Please call for pricing.
* Parylene is a trade mark of Union Carbide. Kapton is a trade mark of DuPont. Elgiloy is a trade mark of Elgiloy Ltd.