Form-function relations in cone-tipped stimulating microelectrodes.
Metal microelectrodes are widely used in neuroscience research, and could potentially replace macroelectrodes in various neuro-stimulation applications where their small size, specificity, and their ability to also measure unit activity are desirable. The design of stimulating microelectrodes for specific applications requires knowledge on how tip geometry affects function, but several fundamental aspects of this relationship are not yet well understood. This study uses a combined experimental and physical finite elements simulation approach to formulate three new relationships between the geometrical and electrical properties of stimulating cone-tipped tungsten microelectrodes: (1) The empirical relationship between microelectrode 1-kHz impedance and the exposed tip surface area is best approximated by an inverse square-root function (as expected for a cone-tipped resistive interface). (2) Tip angle plays a major role in determining current distribution along the tip, and as a consequence crucially affects the charge injection capacity of a microelectrode. (3) The critical current for the onset of corrosion is independent of tip surface area in sharp microelectrodes.
Yaeli
Steve
S
Faculty of Biomedical Engineering, Technion - Israel Institute of Technology Israel.
Binyamin
Einat
E
Shoham
Shy
S
J Neurosci Methods. 2005 Feb 15;141(2):171-98
15661300
IEEE Trans Biomed Eng. 2006 Apr;53(4):726-37
16602580
J Neurosci Methods. 2006 Jan 30;150(2):212-27
16095718
J Neurophysiol. 2006 Aug;96(2):512-21
16835359
IEEE Trans Biomed Eng. 1987 Sep;34(9):664-8
3653908
Electroencephalogr Clin Neurophysiol. 1997 Mar;102(3):228-39
9129578
J Neurosci Methods. 2005 Mar 30;142(2):251-65
15698665
IEEE Trans Biomed Eng. 2005 Jul;52(7):1295-302
16041993
J Neural Eng. 2006 Mar;3(1):1-8
16510937
J Neurosci Methods. 1996 Mar;65(1):1-17
8815302
IEEE Trans Biomed Eng. 1992 Jun;39(6):635-43
1601445
IEEE Trans Biomed Eng. 1984 Dec;31(12):827-32
6396208
Nat Clin Pract Neurol. 2007 Aug;3(8):444-52
17671522
Ann Biomed Eng. 1992;20(3):349-62
1443829
IEEE Trans Biomed Eng. 2007 Jun;54(6 Pt 1):1089-96
17554827
Nat Neurosci. 2002 Nov;5 Suppl:1085-8
12403992
IEEE Trans Biomed Eng. 1983 Jul;30(7):399-406
6618507
Ann Biomed Eng. 2001 Mar;29(3):227-35
11310784
Vision Res. 1999 Jul;39(15):2577-87
10396626
Lancet Neurol. 2002 Aug;1(4):225-31
12849455
IEEE Trans Rehabil Eng. 1999 Sep;7(3):315-26
10498377
Clin Neurophysiol. 2004 Mar;115(3):589-95
15036055
Brain Res. 2003 Sep 5;983(1-2):23-35
12914963
IEEE Trans Biomed Eng. 1991 May;38(5):401-8
1874521
Annu Rev Biomed Eng. 2005;7:361-401
16004575
J Clin Neurophysiol. 2004 Jan-Feb;21(1):6-17
15097290