Micro/nano- particulate fluid manipulation in AC electro-kinetic lab-on-a-chip

Abstract

Integrating fluid transport systems on a single chip with micro-scale detectors has significant advantages, including increased resolution, faster response, smaller sample sizes, and increased parallelism of analysis. To realize the detection of low concentration bioparticles, conventional techniques involve sample culturing to increase particle count to a critical mass at the detection sites, which is time-consuming and often unfeasible under field conditions. By attracting target cells from the bulk onto the sensing electrodes to enrich local cell count in real time, sensitivity can be increased by orders of magnitude. Directed line formation of particles on designated electrodes can be realized by our new asymmetric polarization AC electro-osmotic (ACEO) mechanism based on electrochemical reaction, which shows better particle trapping than that of conventional ACEO. This paper also presents a cantilever ACEO particle trap.

MEMS Microfluidics for Lab-on-a-Chip Applications

“…That means for the mass loading on the cantilever the resonance frequency is supposed to go down. The parallel plate design has been used to attract particles onto cantilevers for high sensitivity detection [14]. Because particle trapping/concentrating effect is more obvious with the smaller electrode, in our design the metal-coated cantilevers are facing one large electrode (covering a whole fluid chamber), so that particles will aggregate on the cantilevers.…”