Electrochemomechanical energy conversion efficiency in curved rectangular nanochannels

Nanofluidic devices based on electrokinetic phenomena can have a major impact on the investigations of electric energy harvesting due to the possibility of opening a new avenue in the exploration of new energy sources. Many efforts have been made by a lot of experts to improve the performance of these devices. However, these efforts are still focused mainly in straight channels. In present study, a curved nanochannel with rectangular cross section is introduced to enhance the electrokinetic energy conversion efficiency. In practice, curved channels are often encountered in lab-on-chip systems due to the advantage of increasing the effective channel length per unit chip length in the flow direction. However, despite its importance, no one have investigated the electric energy conversion in such channels before. We present a theoretical study based on the solution of the linearized Poisson-Boltzmann equation. Our model yields analytical expressions for electrostatic potentials, fluid velocity, streaming potential and the energy conversion efficiency. The results show that, under certain parameter ranges, the electric energy conversion efficiency in curved rectangular nanochannel is 1.17 times larger than that in a straight one. The present endeavor is useful in designing more effective electrochemomechanical energy conversion devices.