High Sensitivity Particle Detection by Biased AC Electroosmotic Trapping on Cantilever

Real-time detection of low-concentration pathogenic/toxic bioparticles is important for deterring infectious diseases and bioterrorism, which is difficult to achieve for lab-on-a-chip. Currently sensitivity is achieved through time-consuming culturing or sophisticated processing, often unfeasible under field conditions. By microfluidic convection of particles from solution bulk onto sensing electrodes, local cell count can be greatly enriched and sensitivity can be increased significantly. This paper discusses how AC electro-osmosis (ACEO) is applied to trap particles in labs-on-a-chip. A new technique – biased ACEO is developed for effective particle trapping, and its integration with cantilevers is prototyped to reach ultra high detection sensitivity.