Multichannel Systems MEA Manual - Manual (Page 21)

MEA Manual
21
4.9 Perforated MEAs for Use with MEA2100-32-System
and USB-MEA32-STIM4-System
pMEA-32S12-L1, pMEA-32S12-L2, pMEA-32S12-L3, pMEA-32S12-L4
pMEA-32S12-Lx
For the USB-MEA32-STIM4-System small perforated MEAs have been designed. Please see USB-MEA32-
STIM4 manual for detailed information. Additionally the MEA2100-32-System is adapted for these small
type of MEA. The pMEAs are different in size, but identical in function to the regular pMEAs. Layout 1
(pMEA-32S12-L1) of the perforated MEAs designed for the MEA2100-32- and for the USB-MEA32-
STIM4-System has been optimized for acute hippocampal slices.
The flat, round electrodes are made of titanium nitride (TiN) with a diameter of 30 μm for the recording
electrodes, and 50 μm for the stimulation electrodes. The stimulation electrodes can not be used for
recording, and vice versa. The interelectrode distances vary from 150 to 200 μm. MEAs with titanium
nitride (TiN) electrodes are very stable. Therefore, the pMEA can be reused several times and is perfect for
long-time experiments (up to several weeks and even months). The electrode impedance ranges between
30 k and 50 k. Tracks and contact pads are made of titanium nitride (TiN), the insulation material is
polyimide, respectively.
The electrodes are integrated into a thin polyimide foil. This thin foil is fixed on a ceramic waver for
mechanical stability. In the middle of the waver, under the electrode field, there is a hole that makes it
possible to access the electrode field from below. The area around the electrodes is perforated to apply
suction to the slice from below. The total area of the holes averages 0.8 mm, the diameters of the holes
varies from 20 to 90 μm. Please read chapter "Working with the USB-MEA32-STIM4 Amplifier"
in USB-MEA32-STIM4 manual or “Setting up the MEA” in the MEA2100 manual.
Using pMEAs
Perforated MEAs have a robust ceramic carrier, but the electrodes are embedded in polyimide foil.
Therefore they are heat stable to 50 °C only, and cannot be autoclaved. Please do not use an ultrasonic
bath for cleaning.