Electroosmotic Flow Rectification in Pyramidal-Pore Mica Membranes

Abstract

We demonstrate here a new electrokinetic phenomenon, Electroosmotic flow (EOF) rectification, in synthetic membranes containing asymmetric pores. Mica membranes with pyramidally shaped pores prepared by the track-etch method were used. EOF was driven through these membranes by using an electrode in solutions on either side to pass a constant ionic current through the pores. The velocity of EOF depends on the polarity of the current. A high EOF velocity is obtained when the polarity is such that EOF is driven from the larger base opening to the smaller tip opening of the pore. A smaller EOF velocity is obtained when the polarity is reversed such that EOF goes from tip to base. We show that this rectified EOF phenomenon is the result of ion current-rectification observed in such asymmetric-pore membranes.

A tunable nanopore sensor for the detection of metal ions using translocation velocity and biphasic pulses

“…Secondly, in each ionic strength and pH experiment the zeta potential of the pore wall would need to be known to calculate the zeta potential of the particle. 24,56 To keep the method simple and applicable in further applications the actual zeta potential of the particle is not calculated and for further simplicity in the subsequent figures we use only one measurement to represent the particle speed which is 1/T 0.50 .…”

Low-voltage electroosmotic pumping using polyethylene terephthalate track-etched membrane

“…Recently, researchers notice that membrane-based EO pump is promising for low-voltage operation, since this kind of EO pump can be easily fabricated with a thinner membrane with a high electric field when a lower voltage is applied. Porous silicon membranes [18] and porous anodic alumina membranes [19][20][21] [22].In this study, we applied PET track-etched membrane in low-voltage EO pumping. A low-voltage EO pump based on PET track-etched membrane has been designed, fabricated, tested, and analyzed.…”

Layer-by-layer removal of insulating few-layer mica flakes for asymmetric ultra-thin nanopore fabrication

“…Among such layered materials, mica is chemically inert and insulating to heat and electricity [5][6][7]. These attractive chemical and physical properties make mica a favored material for radio frequency capacitors, high voltage electrical insulators, solid lubrication for nanoscale friction, and atomically flat substrates [8][9][10][11].…”