The electrophysiological activity monitoring of living cells with chemical sensor array based microsystems represents an emerging technique in a large area of biomedical applications, ranging from the basic research to various fields of the pharmacological analyses. The main attraction consists in the availability of a miniaturised system to perform non-invasive in vitro, in real time, investigations of the physiological state of a cell population. In the last decade, metallic microelectrode array based systems for the electrophysiological activity recording from neurons in culture have been studied and optimised. Arrays of ISFET have also been recently proposed. However, the design of combined microsystems demands the availability of a fabrication process able to integrate different technologies as those utilised for the fabrication of ISFET sensors, metallic microelectrodes and 3-dimensional structures (micromachining). In this paper, we present a modified ISFET/CMNOS (Ion Sensitive Field Effect Transistor / Complementary Metal Nitride Oxide Semiconductor) fabrication technology for electrochemical sensors combined with gold microelectrode arrays. The developed technology consists of a 4µm Al gate p-well CMNOS process where one of the main features is to make use of a Si3N4/SiO2 double layer gate insulator. With respect to the original one, this process requires two new mask levels for the microelectrode and the passivation polymeric layer. In a preliminary evaluation step of the technology, two different microsystem typologies have been realised. The first, equipped with chemical sensors only, is intended for the cellular metabolism monitoring. The second one, realised with chemical sensor and microelectrode arrays has been designed to monitor the neuron culture electrical activity by direct coupling the neuronal culture with the ISFET sensitive layer and utilising the gold microelectrodes for the electrical stimulation of the neurons.
Microsystem Fabrication for Microphysiological Applications
Lorenzelli, Leandro;Margesin, Benno;Giacomozzi, Flavio;Zen, Mario
2001-01-01
Abstract
The electrophysiological activity monitoring of living cells with chemical sensor array based microsystems represents an emerging technique in a large area of biomedical applications, ranging from the basic research to various fields of the pharmacological analyses. The main attraction consists in the availability of a miniaturised system to perform non-invasive in vitro, in real time, investigations of the physiological state of a cell population. In the last decade, metallic microelectrode array based systems for the electrophysiological activity recording from neurons in culture have been studied and optimised. Arrays of ISFET have also been recently proposed. However, the design of combined microsystems demands the availability of a fabrication process able to integrate different technologies as those utilised for the fabrication of ISFET sensors, metallic microelectrodes and 3-dimensional structures (micromachining). In this paper, we present a modified ISFET/CMNOS (Ion Sensitive Field Effect Transistor / Complementary Metal Nitride Oxide Semiconductor) fabrication technology for electrochemical sensors combined with gold microelectrode arrays. The developed technology consists of a 4µm Al gate p-well CMNOS process where one of the main features is to make use of a Si3N4/SiO2 double layer gate insulator. With respect to the original one, this process requires two new mask levels for the microelectrode and the passivation polymeric layer. In a preliminary evaluation step of the technology, two different microsystem typologies have been realised. The first, equipped with chemical sensors only, is intended for the cellular metabolism monitoring. The second one, realised with chemical sensor and microelectrode arrays has been designed to monitor the neuron culture electrical activity by direct coupling the neuronal culture with the ISFET sensitive layer and utilising the gold microelectrodes for the electrical stimulation of the neurons.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
