A model for simulating the flow of fluid through a microcantilever sensor cell

Abstract

Microcantilever sensors are highly sensitive detectors capable of detecting target chemicals in solutions with concentrations in the parts per billion. Commercial and custom built sensor-based instruments make use of one or more probes consisting of eight cantilevers each. Until now the cantilevers have been treated equally, however, since they are in different locations with respect to the flow of input target chemicals this might not be the case. It is important to understand the concentration of targets in the vicinity of each cantilever to see what concentration each cantilever actually experiences. In this work we developed a model to simulate fluid motion throughout the cantilever sensor cell. It was found that there is a lot of variability in the flow across the cantilevers, which is suspected to impact the absorption rate. In accordance with the flow, there are regions of high and low pressure on the surface of the cantilevers, which could result in misleading deflection readings. Understanding the fluid motion is the first step towards properly understanding the deflection signal of each cantilever.