Novel Sensor for Rapid Detection of Blood Cell Types-Magnetostrictive Microcantilevers

Abstract

Microcantilevers have been around since the development of atomic force microscopy. The main attraction of cantilevers results from the fact that they can transduce many different signal domains into mechanical signals. Microcantilevers have different operational modes, but the one presented in this thesis is the dynamic microcantilever. Dynamic mode involves oscillation of the microcantilever at its resonance frequency. The main attraction of dynamic microcantilevers is that their resonance frequency is directly related to the mass attached to the microcantilever. Whenever mass is added to the surface of a microcantilever, a shift of resonance frequency will result. By monitoring the resonance frequency shift, the amount of mass added to the microcantilever can be determined. This type of detection can be applied in different fields including food science, environmental monitoring, and medical industries. Bacteria detection that usually takes up to a couple of days for identification can be analyzed within minutes using sensors like microcantilevers. Recently, more publications are focusing on employing microcantilevers as biosensors to detect anything from Salmonella in food to E-coli in water. The objective of this thesis is to fabricate magnetostrictive microcantilevers and demonstrate the capabilities and advantages by using them to detect blood types. By observing the resonance frequency shift of the magnetostrictive microcantilevers, A and B blood types can be distinguished. Also presented in this thesis is the development of magnetostrictive thin films by electrochemical deposition. The thin film process allows numerous sensors to be fabricated with sizes ranging into the microns. These sensors can be made into microcantilevers. The magnetostrictive microcantilevers presented here can be driven and sensed wirelessly and also have a higher quality-value (Q-value) than other microcantilevers. By observing shifts in its resonance frequency due to blood cell loading, there seems to be some potential in being able to distinguish between certain blood types.