Steric-effect-induced enhancement of electrokinetic energy conversion efficiency in curved nanochannels with rectangular sections at high zeta potentials

In this work, we investigate the electrokinetic energy conversion in curved rectangular nanochannels at high zeta potentials, intending to increase the efficiency of electrokinetic generation. As we demonstrate, the geometry effect can have an important role in the investigations of the conversion efficiency. In addition, we consider the influences of steric effect (the effect of finite ion size) on the energy conversion efficiency, which is significant and can't be ignored, especially at high surface potentials. The finite difference method is used to obtain numerical solutions for the corresponding efficiency. Our results show that, within optimized parameters ranges, the conversion efficiency can be increased by up to 50 percent by considering the influences of the steric effect. Additionally, the conversion efficiency eta shows a increasing trend with the curvature ratio S and a reversed trend with the aspect ratio AR of the rectangular cross section. These results are useful for estimating and designing more effective electrokinetic energy conversion devices.