Understanding the structure and function of proteins has become increasingly important since the completion of the Human Genome Project and the sequencing of several other important genomes. In recent years, lab-on-a-chip systems have introduced some new capabilities for protein analyses. Rapid progress in the field of microsystems, miniaturized devices combining sensor and electronics, enable a new generation of miniaturized biosensor arrays integrating silicon CMOS chips that acquire and process bio-electrochemical signals. Such biosensor array microsystems could permit improved sensitivity, throughput and cost. Because many proteins exhibit temperature dependent activity, this thesis explores the opportunity to develop a thermal control microsystem for protein arrays biosensors. A CMOS microhotplate array was developed for thermoregulation of protein interfaces in a liquid sample environment. The microhotplates were shown to provide suitable thermal control for biosensor temperature ranges without the process complexity of most previously reported microhotplates. When combined with a CMOS analog thermal controller, the on-chip array was shown to set and hold temperatures for each protein site within ±1°C, and array elements were found to be almost completely thermally isolated from each other at distances beyond 0.4mm. Furthermore, a new compact, low power impedance analysis circuit was developed utilizing mixed-mode signal processing to extract real and imaginary impedance components for an on-chip protein interface. The compact size and low power of this circuit enable it to be combined with the thermal control structures and instantiated for every element in a sensor array to increase the interrogation throughput. The developed thermal control and readout microsystem could significantly advance proteomics research and progress in characterizing newly sequenced genomes.
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