First particle measurements with an integrated Coulter counter based on 2-dimensional aperture control

In this paper we present first-time measurement results for an integrated Coulter counter device with a liquid aperture. A non-conductive sheath liquid that partially surrounds the sample liquid defines the Coulter aperture. The dimensions of the aperture can be dynamically adapted by changing the flow-rates of the sample liquid and the sheath liquid. An advantage of this approach is that it prevents channel blocking, since the channel´s physical dimensions can be much larger than the Coulter aperture. The measurement results show that a high sensitivity can be obtained in a channel with relatively large physical dimensions.