Conventional microelectrode arrays (MEAs) allow the user to record simultaneously from a very small number of neurons, resulting in the recording of only a fraction of the active neurons within the network. At 3Brain, we have worked for many years to introduce CMOS-APS technology in the field of electrophysiology and functional imaging. CMOS-APS technology overcomes the limitations of conventional MEAs by drastically increasing the number of simultaneously recording electrodes up to several thousands.
CMOS-technology is used to fabricate cost-efficient systems such as microprocessors, wireless receivers, GPS and cameras. We have pushed the MEA technology to new dimensions by using the concept of active-pixel-sensor technology (APS) employed in the world of imaging devices and cameras. Instead of light sensitive elements used for camera chips, we integrate a metallic electrode into each unit element, called a pixel. The pixel has the shape of a square with the size of a few tens of micrometres.
A large number of these squares are aligned into a matrix of microelectrodes to build an MEA, leading our customers to a new disruptive method to perform measurements with a density of detail orders of magnitude higher compared to that obtained with conventional MEAs.
Each pixel integrates amplification and filter stages directly where the biological signals are measured. Consequently, the signal from each electrode can already be processed and enhanced at a local level. Unlike the conventional MEA technology, we can output the signals from many electrodes onto a single wire. Thereby, we save a lot of interconnection lines, which leads to them being much smaller and shorter, as well as the electronics blocks used to process these signals being smaller. In addition, this approach is highly scalable with respect to the number of electrodes and the interconnections, which do not have to scale accordingly.