Ultra Sensitive Piezoelectric-Based Microcantilever Sensor Operating at High Modes for Detection of Ultrasmall Masses

Abstract

Detection of ultrasmall masses such as proteins and pathogens has been made possible as a result of nano-technological advancements. Development of label-free and highly sensitive biosensors has enabled the transduction of molecular recognition into detectable physical quantities. MicroCantilever (MC)-based systems have played a widespread role in developing such biosensors. One of the most important drawbacks of the available biosensors their high cost. Moreover, biosensors are normally quipped with external devices such as actuator and read out systems which are bulky and expensive. A unique self-sensing detection technique is proposed in this paper in order to address the limitations of the measurement systems. A number of approaches have been reported for enhancing the sensitivity of MC-based systems including geometry modification, employing nanoparticle-enhanced MCs and operating MCs in lateral and torsional modes. Although being investigated, there have not been analytical high fidelity models describing comprehensive dynamics and behavior of MCs operating in high modes. In this study, a comprehensive mathematical modeling is presented for the proposed self-sensing detection platform operating at ultrahigh mode using distributed-parameters system modeling. Mode convergence theory was adopted to have an accurate level of estimation. An extensive experimental setup was built using piezoelectric MC operating at high mode which verified theoretical modeling results. Finally, the whole platform was utilized as a biosensor for detection of ultrasmall adsorbed mass along with the theoretical and experimental results and verification. It was proved that operating MC at ultrahigh mode increases the sensitivity of system to detect adsorbed mass as a result of increased quality factor.