PMID-28246640 Ultraflexible nanoelectronic probes form reliable, glial scar–free neural integration
- SU-8 asymptotic H2O absorption is 3.3% in PBS -- quite a bit higher than I expected, and higher than PI.
- Faced yield problems with contact litho at 2-3um trace/space.
- Good recordings out to 4 months!
- 3 minutes / probe insertion.
- Fab:
- Ni release layer, Su-8 2000.5. "excellent tensile strength" --
- Tensile strength 60 MPa
- Youngs modulus 2.0 GPa
- Elongation at break 6.5%
- Water absorption, per spec sheet, 0.65% (but not PBS)
- 500nm dielectric; < 1% crosstalk; see figure S12.
- Pt or Au rec sites, 10um x 20um or 30 x 30um.
- FFC connector, with Si substrate remaining.
- Used transgenic mice, YFP expressed in neurons.
- CA glue used before metabond, followed by Kwik-sil silicone.
- Neuron yield not so great -- they need to plate the electrodes down to acceptable impedance. (figure S5)
- Measured impedance ~ 1M at 1khz.
- Unclear if 50um x 1um is really that much worse than 10um x 1.5um.
- Histology looks realyl great, (figure S10).
- Manuscript did not mention (though the did at the poster) problems with electrode pull-out; they deal with it in the same way, application of ACSF.
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