Caratterizzazione di un front chip integrato CMOS 0.35um per sistemi di rilevazione di segnali neuronali con microelettrodi al diamante

The objective of this thesis is to characterize an Analog Front End for cellular electrical signal recording systems based on diamond microelectrodes. MEA (MicroElectrode Array) is a recent non-invasive method which estimates the transmembrane potential variation measuring the ion concentration change in extracellular medium surrounding the cell. This method makes it possible to have hundreds of recording channels. The microelectrodes aren't in metal but in hydrogenated diamond that is biocompatible, optically transparent and it has low noise level. The tested microchip is an integrated circuit in CMOS AMS 0.35 um technology: it is a low noise amplifier with three different channel. Its characteristics are very low noise, low power consumption, DC voltage rejection and a cut off frequency of some kHz. The thesis is structured as follows: 1. Introduction: It contains a short description of neurons electrical activity and cultured cell recording methods. It introduces the use of MEA as biosensors and gives attention to the diamond as new material for microelectrodes. 2. Complete chip layout: It describes the single channels and its architecture 3. Experimental setup: It shows the chip's tab diagram and the bonding diagram and it describes the setup for testing 4. Measurements: It shows the results of measurements compared with simulations 5. Conclusions and future work