Erratum to: Capillary pumps with constant flow rate

3. In the second line underneath Eq. 28, the first reference to Eq. 27 is erroneous and should refer to Eq. 26 instead. The correct sentence should thus read: Eqs. 20, 23, 25 (alternatively 26) and 27 unambiguously describe the shape of a single channel with rectangular cross section that provides a constant flow rate when used as CP 4. Under section 5, right column, the first sentence includes an error in the choice of value for wmax. The corrected sentence should read: