A microelectrode is an electrode used in electrophysiology either for recording neural signals or for the electrical stimulation of nervous tissue.12 They were first developed by Ida Hyde in 1921.3 Pulled glass pipettes with tip diameters of 0.5 μm or less are usually filled with 3 molars potassium chloride solution as the electrical conductor. When the tip penetrates a cell membrane the lipids in the membrane seal onto the glass, providing an excellent electrical connection between the tip and the interior of the cell, which is apparent because the microelectrode becomes electrically negative compared to the extracellular solution. There are also microelectrodes made with insulated metal wires, made from inert metals with high Young modulus such as tungsten, stainless steel, or platinum-iridium alloy4 and coated with glass or polymer insulator with exposed conductive tips. These are mostly used for recording from the external side of the cell membrane.
References
References
- Kita, Justin M; Wightman, R Mark (October 2008). "Microelectrodes for studying neurobiology". Current Opinion in Chemical Biology. 12 (5): 491–496. doi:10.1016/j.cbpa.2008.06.035. PMC 2642896. PMID 18675377.
- "Electroanalytical techniques in biosciences: conductometry, coulometry, voltammetry, and electrochemical sensors", Analytical Techniques in Biosciences, Academic Press, pp. 157–178, 2022-01-01, doi:10.1016/B978-0-12-822654-4.00004-X, retrieved 2026-03-13
- Johnson, Elsie (1981). "Ida Henrietta Hyde: Early Experiments" (PDF). Physiologist. 24 (6): 1–2. PMID 7043502. Archived from the original (PDF) on 2011-05-23. Retrieved 2009-04-26.
- Cogan, Stuart F. (August 2008). "Neural Stimulation and Recording Electrodes" (PDF). Annual Review of Biomedical Engineering. 10 (1): 275–309. doi:10.1146/annurev.bioeng.10.061807.160518. PMID 18429704. S2CID 25087051. Archived from the original (PDF) on 2019-02-20.