Thermal control of ionic transport and fluid flow in nanofluidic channels

Abstract

In this work, we report a nanofluidic gating mechanism that uses the thermal effect for modulating the ionic transport inside nanofluidic channels. The control of the ionic transport inside a nanochannel is demonstrated using electrical conductivity. A thermal gate controls the ionic transport more effectively than most of the other gating mechanisms previously described in the scientific literature. Gating in both bulk and overlapping electric double layer regimes can be obtained. The relatively short response time of opening and closing processes makes it a good candidate for manipulating small molecules in micro- and nanoscale devices.

Can Nanofluidic Chemical Release Enable Fast, High Resolution Neurotransmitter-Based Neurostimulation?

“…Progress in nanofluidics has focused on nanopores: channels narrower than 100 nm fabricated perpendicularly through thin membranes. Exploitation of the influence of surface properties can control transport of ions or fluid, although electrostatic or steric effects have not achieved absolute shut-off (Taghipoor et al, 2015 ). A suitable technique to prevent diffusion requires a barrier to interrupt the aqueous phase.…”

Size and roughness dependent temperature effects on surface charge of silica nanoparticles

“…where λ 0 i @298.15 is the limiting conductance at T = 298.15 K and ΔT = T − 298. 15. The corresponding values of the parameters λ 0 i @298.15 , a i1 , a i2 and a i3 for H + , OH − and Cl − ions can be found from the literature as tabulated in Table 1 [10,60,61].…”

“…While the variation of surface electric properties appears a complication to be considered for a successful electrophoresis-based application, it also emerges as a mechanism to control/manipulate the associated physics. This idea was implemented in a nanofluidic gating mechanism known as "Thermal Gate" where heating up and cooling down channel surface controls the ionic transport [15]. Similarly, temperature has been found to be a key determinant in salinity-gradient-driven energy conversion processes [16].…”

“…Similarly, temperature has been found to be a key determinant in salinity-gradient-driven energy conversion processes [16]. Simply, temperature increases the ionic transport by increasing the ionic mobility and silica surface charge [15,[17][18][19]. Hence, multiple studies have been dedicated to investigate temperature dependent variation of surface charge of silica.…”

Temperature effects on electrical double layer at solid‐aqueous solution interface

“…The electrochemical properties of the EDL can be manipulated by means of several parameters, such as ion concentration, solution pH, metaloxide surface site density, chemical equilibrium constants [9,10], and solution temperature [11][12][13], where the former parameters have been extensively studied through large body of literature [1,[14][15][16]. Quite surprisingly, temperature effects on structure of EDL at the vicinity of a chemically active solid surface have drawn less attention or ignored to expedite the analysis while it emerges as a determinative factor in many microand nanofluidics applications [17][18][19][20][21][22][23][24][25][26][27]. Several experimental works have shown that the zeta potential of solid-aqeuous interface is not only a function of bulk ion concentration and solution pH but also solution temperature [13,26,[28][29][30][31][32].…”