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Microelectrode Arrays

Microelectrode arrays, also called multielectrode arrays (MEAs), for the analysis of electrically active cells (e.g., cardiomyocytes, neurons) are an easy-to-use replacement of the patch clamp technique. The specialty of GeSiM's MEA system is the integration of the MEA chip into a microfluidic system.

Working Principle

The multielectrode array is micromachined on a disposable and autoclavable glass chip. Cells are grown on a support of poly(L-lysine) or laminin, which can also be structured by microcontact printing. The chip is reversibly fixed on a silicon-glass manifold (Fig. 1) containing an injector that allows to dispense various fluids into the channel. The fluid injection can be performed automatically with the Nano-PlotterTM . The whole system is mounted in an electrically shielded and thermostated housing.

Enlarge...  Top View
Fig. 1: Flowthrough MEA, cross section (schematic)
 Fig. 2: Flowthrough MEA, layout design of the manifold with the injector sieve and the micro electrode array (the small green area in the middle of the image) with electrical connectors (in blue on the right).

Injector

As a core component of the MEA system, the microinjector, together with a dispense unit - acts as a fluidic selector valve. It comprises a micromachined sieve - "microfluidic diode" - and merges dispensed liquids into the carrier flow of the MEA flow-through-manifold.

Injector Photo
Fig. 3: Schematic view of the injector 1) "Microfluidic diode"
2) Injector body
3) Spacer level
4) MEA manifold

MicCell with MEA

A recent development is the integration of MEAs into our flexible microfluidic platform, MicCell . This allows the microscopic observation of cells while their electrical signals are recorded at the same time. 

Sample Injection MicCell MEA
Fig. 4: Nano-Plotter pipette above the injector of a flowthrough MEA in a shielding box.
 Fig. 5: MicCell with coverslip
 Fig. 6: Coverslip with two MEAs.

 

In collaboration with MPI für Polymerforschung, Mainz.