Multiplexed biosample delivery with surface patterned microstructure for microcantilever

We introduce the novel method of self-propelling slugs for the biosample delivery for the application of a microcantilever biosensor. By implementing a surface patterned microstructure with a hydrophobic SU8 barrier, we demonstrated a top plate-less channel for biosample delivery without external electrokinetic force or pressure-driven flows. With a simply-patterned hydrophobic layer both on SiO2 and Au surfaces, which was favourably used for the biosensor surface, we were able to drive PBS solutions onto cantilever sensors by capillary actions. The measured flow velocity of the SU8 barrier with SiO2 surface reveals a linear increase with barrier height. With the Au bottom surface, we observed that the flow velocity is inversely proportional to channel width, at approximately 100 μm, while proportional linearly below 100 μm. The present micro-patterned structure integrated with microcantilever could help us with the ease of integrating the fluidic channel as well as multiplexing for bio/chemical sensors.