PMID-4708761 Design, Fabrication, and In Vivo Behavior of Chronic Recording Intracortical Microelectrodes
- Teflon-coated 25um Pt-Ir (90/10)
- Heat fuse this with a glass micropipette & backfill with cyanoacrylate. {1011}
- Isobutyl acrylate is hydrolysed more slowly and hence is less toxic to the surronding tissue
- cyanoacrylate is apparently biodegradable.
- Durable, stable: one electrode displayed a single cortical spike (though not necessarily the same one) for more than 90 consecutive days.
- unacceptably low impedance = 100K or less
- Unit activity was present only 10-24H after surgery.
- formal review of even older microelectrode studies.
- 10nA should be 100x too small to have any effect on a platinum tip [17]
- A seperable cell with a SNR of 3:1 would become lost if the electrode tip moved 15um away from a 20um soma.
- "It becomes clear that the problem of holding single units for prolonged periods in the unrestrained animal is not achieved without considerable difficulty". Yet they think they have solved it.
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____References____
Salcman, Michael and Bak, Martin J. Design, Fabrication, and In Vivo Behavior of Chronic Recording Intracortical Microelectrodes Biomedical Engineering, IEEE Transactions on BME-20 4 253 -260 (1973) |