Power Generation by Pressure-Driven Transport of Ions in Nanofluidic Channels

• Published in: Nano letters Vol. 7; no. 4; pp. 1022 - 1025
• Main Authors: van der Heyden, Frank H. J, Bonthuis, Douwe Jan, Stein, Derek, Meyer, Christine, Dekker, Cees
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-04-2007
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Electric Power Supplies; Electricity; Electrochemistry - instrumentation; Electrochemistry - methods; Electronics; Equipment Design; Equipment Failure Analysis; Exact sciences and technology; Ions; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Micro- and nanoelectromechanical devices (mems/nems); Microfluidics - instrumentation; Microfluidics - methods; Nanotechnology - instrumentation; Nanotechnology - methods; Physics; Pressure; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Nanometer scale; Electric power generation; Aqueous solutions; Ionic strength; Counterions; Electrical conductance; Nanostructures; Experimental study; Nanofluidic circuit
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl070194h

We report on the efficiency of electrical power generation in individual rectangular nanochannels by means of streaming currents, the pressure-driven transport of counterions in the electrical double layer. Our experimental study as a function of channel height and salt concentration reveals that the highest efficiency occurs when double layers overlap, which corresponds to nanoscale fluidic channels filled with aqueous solutions of low ionic strength. The highest efficiency of ∼3% was found for a 75 nm high channel, the smallest channel measured. The data are well described by Poisson−Boltzmann theory with an additional electrical conductance of the Stern layer.