Abstract
An energy conversion microchip consisting of two circular microchambers and a Nafion-filled microchannel is fabricated using standard micro-electro-mechanical systems (MEMS) techniques. When the chambers are filled with KCl solutions with different concentrations, the Nafion microchannel acts as a cation-selective membrane and results in the generation of electrical power through a reverse electrodialysis (RED) process. The current-potential characteristics of the Nafion membrane are investigated for devices with various microchannel lengths and electrolyte concentration ratios. It is shown that for a given voltage, the current and generated power increase with a reducing channel length due to a lower resistance. In addition, a maximum power density of 755 mW/m2 is obtained given an electrolyte concentration ratio of 2000:1 (unit is mM). The optimal device efficiency is found to be 36% given a channel length of 1 mm and a concentration ratio of 1000:1 (mM). Finally, no enhancement of the short circuit current is observed at higher concentration ratios.
Highlights
Most of today’s energy is produced from fossil fuels
This difference results in the formation of a diffusion potential, which is subsequently converted into electrical energy through a process of reverse electrodialysis
7, 205 redox reactions at the electrodes; Ediff is the diffusion potential; Rofc9hannel is the resistance of the microchannel filled with Nafion; and I is the output current generated by the microtchheip.otTehnetiarledapopxlipeodtebnyttihael psoroudrcuecmedetaetr;dEifrefdeorxeisnthceonpcoetennttriaatliopnrordautcioedsecdaonx breeaecxtiponressasted by the fotlhloeweliencgtroNdersn; Estdifrfeislatthioendi[f2fu4s,2io5n]:potential; Rchannel is the resistance of the microchannel filled with
Summary
Most of today’s energy is produced from fossil fuels (e.g., coal, oil and natural gas). To address the problems of environmental pollution and climate change and to prevent future resource depletion, it is necessary to develop alternative green energy sources, such as salinity gradient energy [1,2,3], biomass conversion [4], wind power [5], solar energy [6], and others. Of these various technologies, salinity gradient energy is one of the most attractive since seawater accounts for almost 70% of the planet’s surface. Veerman et al [10] showed that for a scaled-up reverse electrodialysis (RED) stack consisting of 50 cells with a size of 25 cm × 75 cm, a maximum power density of 930 mW/m2 could be achieved given an appropriate hydrodynamic design of the stack
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
