Similar boundary conditions are imposed for all the other channels and for the layer proteins. In order to check the validity of the thermal model the steady-state temperature pro"le (clean conditions) inside the channels were "rst determined. The simulation re- sults are depicted in Fig. 5. Note that the channel bulk temperature increase is maximum in the "rst three chan- nels while it remains almost constant in the last two channel. The results are in a very good agreement with the experimental work of Delplace et al. (1994)