Tungsten is a versatile and widely-used microelectrode material that offers a good balance between performance and cost.
Advantages
Disadvantages
Extremely strong and stiff metal provides probes with exceptional rigidity.
Great for acute and chronic recording due to biocompatibility and lower cost.
High corrosion resistance offers consistent long-term performance.
Does not provide the same degree of electrochemical performance or stability as platinum-iridium alloy, making it a poor alternative for microstimulation.
Lower charge transfer capacity of tungsten will result in larger, potentially unsafe interfacial potentials when applying the same stimulation current as to a platinum-iridium electrode.
Certain pH or stimulation conditions can lead to tungsten corrosion.
These Monopolar Microelectrodes of MicroProbes are, with other tip profile, available also in Platinum/Iridium, Elgiloy (an alloy similar to stainless steel), and Pure Iridium metal. The electrodes are insulated with a thin film of vapor-deposited Parylene-C. As an option we provide them surrounded by Polymide tubing. Each electrode is etched to a fine taper and tipped using a proprietary process to a specific impedance value. Four different tip profiles are available, see below.
The tip selection can provide subtle yet important changes to the performance of the electrode. It is recommended that first time users consider experimenting with different tip profiles to determine which works best for their recording or stimulation protocols.
Monopolar Electrodes, Tungsten, Extra Fine Tip (75 µm × 3")
Item
Length
Shaft Diameter
Tip Diameter
Impedance
Applications
Pkg of 10
WE30030.01F3
76 mm
0.081 mm
1-2 µm
0.01 MΩ
MultiUnit & ERP recording & Stim
WE30030.05F3
76 mm
0.081 mm
0.05 MΩ
WE30030.1F3
76 mm
0.081 mm
0.1 MΩ
WE30030.5F3
76 mm
0.081 mm
0.5 MΩ
Single & multiunit rec. & stim.
WE30031.0F3
76 mm
0.081 mm
1 µm
1.0 MΩ
WE30031.5F3
76 mm
0.081 mm
1.5 MΩ
WE30032.0F3
76 mm
0.081 mm
2.0 MΩ
Greater Selectivity & Micro. Stim.
WE30032.5F3
76 mm
0.081 mm
2.5 MΩ
Greater Selectivity - Small Cells
WE30033.0F3
76 mm
0.081 mm
3.0 MΩ
WE30035.0F3
76 mm
0.081 mm
5.0 MΩ
Monopolar Electrodes, Tungsten, Extra Fine Tip (125 µm × 3")
Item
Length
Shaft Diameter
Tip Diameter
Impedance
Applications
Pkg of 10
WE30030.01F5
76 mm
0.127 mm
1-2 µm
0.01 MΩ
MultiUnit & ERP recording & Stim
WE30030.05F5
76 mm
0.127 mm
0.05 MΩ
WE30030.1F5
76 mm
0.127 mm
0.1 MΩ
WE30030.5F5
76 mm
0.127 mm
0.5 MΩ
Single & multiunit rec. & stim.
WE30031.0F5
76 mm
0.127 mm
1 µm
1.0 MΩ
WE30031.5F5
76 mm
0.127 mm
1.5 MΩ
WE30032.0F5
76 mm
0.127 mm
2.0 MΩ
Greater Selectivity & Micro. Stim.
WE30032.5F5
76 mm
0.127 mm
2.5 MΩ
Greater Selectivity - Small Cells
WE30033.0F5
76 mm
0.127 mm
3.0 MΩ
WE30035.0F5
76 mm
0.127 mm
5.0 MΩ
WE30036.0F5
76 mm
0.127 mm
6.0 MΩ
Common Tip Profiles:
A - STANDARD TIP PROFILE The standard tip profile features a sharp yet robust point that offers versatile performance and an effective balance between penetration and durability.B - BLUNTED TIP PROFILE The blunted electrodes are engineered to have a more rounded, bullet-shaped tip. For many applications the blunted tip can offer superior stimulation performance.H - HEAT TREATED TAPERED TIP PROFILE The heat-treated electrodes are intended for those investigators who must penetrate their probes through tough membranes, such as the dura mater of larger mammals.F - EXTRA FINE TIP PROFILE The extra-fine tip profile features a significantly sharper taper as well as a thinner insulation layer.
