Cellular Signal Acquisition And Processing Based On Microelectrodes

Since the 20 th century, for studies on the molecular level, cell culture technology and semiconductor microfabrication technology were developed persistently; scientists studied various physiological characteristics of cells, especially the electrophysiological properties. Nowadays, biosensors that use living cells as sensitive components have become a hot topic.In this thesis, a weak signal detection system was designed based on microelectronic technology, cell culture technology and signal detection technology to acquire the electric signal of cardiomyocytes. Detection methods of electrophysiological properties of cells were analyzed in detail. Finally, we decide to use microelectrode array(MEA) to record the action potential. The finished work are as following:1. Micron electrode arrays were designed based on the project. Electrodes were plated by gold to reduce electrode impedance, while the hydrophobic of electrode surfaces was improved by using O2 plasma treatment to improve the electrode performance and promote cell growth.2. A signal acquisition system was designed based on the amplitude-frequency characteristic of myocardial action potentials. In order to filter out the baseline wander and high frequency noises, signals were processed through the multi-channel preamplifier filter circuit. Signals were acquired by an upper computer based on LabVIEW, and then were displayed and saved.3. Signals were processed using Matlab to improve their SNRs, and then the obtained features reflected the cells' states in some ways.