An electrophysiological lab on a chip

We present the successful integration of an electroosmotic flow pump and a patch-clamp orifice in the same package. When experiments are performed the electroosmotic pump is used both to position e.g. a single HEK293 cell on a micron-sized orifice and later to rupture the cell membrane, to bring the cell in the whole-cell configuration. In this configuration we are able to perform high quality electrophysiological ion-channel measurements. In the experiments we have used a sieve geometry for the pump. This design is a particularly promising candidate for such an integration scheme. The sieve pumps have relatively low volumetric flow rates, but are able to supply relatively high stall pressures (>200mbar), which make the sieve pumps well suited to work on a load with a high flow resistance e.g. a patch-clamp orifice. In the following we present a characterisation of such electroosmotic sieve pumps. For our system we were able to determine the zeta-potential of the glass/electrolyte interface of to be well above 10mV. Furthermore we also present ion-channel measurements performed on this integrated platform.