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A biohybrid system composed of neuronal cells and silicon-supported nanoporous membranes has been designed to facilitate control of the biochemical environment of neuronal networks with cellular resolution. The membranes may exhibit variable pore sizes and interpore distances and are interfaced to a microfluidic device. Different porosity parameters give rise to changes in the transconductance of the nanopores and can therefore be used to control diffusion of molecules through the membranes. It was shown that the porous membranes are biocompatible with primary vertebrate as well as insect neurons. Our results indicate that nanoporous membranes may be used to interface with biological materials in a biohybrid system, for example as an artificial chemical synapse interface. [ABSTRACT FROM AUTHOR]

We present a new nanocavity device for highly localized on-chip recordings of action potentials from individual cells in a network. Microelectrode recordings have become the method of choice for recording extracellular action potentials from high density cultures or slices. Nevertheless, interfacing individual cells of a network with high resolution still remains challenging due to an insufficient coupling of the signal to small electrodes, exhibiting diameters below 10 µm. We show that this problem can be overcome by a new type of sensor that features an electrode, which is accessed viaa small aperture and a nanosized cavity. Thus, the properties of large electrodes are combined with a high local resolution and a good seal resistance at the interface. Fabrication of the device can be performed with state-of-the-art clean room technology and sacrificial layer etching allowing integration of the devices into sensor arrays. We demonstrate the capability of such an array by recording the propagation of action potentials in a network of cardiomyocyte-like cells. [ABSTRACT FROM AUTHOR]

Microelectrode arrays (MEAs) are gaining increasing importance for the investigation of signaling processes between electrogenic cells. However, efficient cell–chip coupling for robust and long-term electrophysiological recording and stimulation still remains a challenge. A possible approach for the improvement of the cell–electrode contact is the utilization of three-dimensional structures. In recent years, various 3D electrode geometries have been developed, but we are still lacking a fabrication approach that enables the formation of different 3D structures on a single chip in a controlled manner. This, however, is needed to enable a direct and reliable comparison of the recording capabilities of the different structures. Here, we present a method for a precisely controlled deposition of nanoelectrodes, enabling the fabrication of multiple, well-defined types of structures on our 64 electrode MEAs towards a rapid-prototyping approach to 3D electrodes. [ABSTRACT FROM AUTHOR]