Quasi-static drainage in a network of nanoslits of non-uniform depth designed by grayscale laser lithography

Abstract

Fig. 1 Flowchart of the fabrication process. a Principle of grayscale laser lithography to fabricate varying-depth nanochannels in one step. b Nanochannels are integrated in the nanofluidic chips with standard fabrication steps. c Scheme of the final nanofluidic chip

Pore network model of drying with Kelvin effect

“…30 It has been shown that the IP rules are still valid in mesoporous materials. 31,32 This model is summarized later. The new features introduced for the present study are described afterward.…”

Synergistic actions of mixed small and large pores for capillary absorption through biporous polymeric materials

“…For the monoporous sample LP70, our results show so slow an imbibition rate that they cannot be described by eqn (4). Indeed, we have increased the value of % r in eqn (4) in order to reduce the front velocity, but for values % r 4 400 mm the Jurin height becomes smaller than the observed front heights (see Fig.…”

“…1 Water absorption is important for food processing (rehydration) and preservation, 2 as well as for the basic process underlying ink writing, where liquids spread on a rough porous substrate, 3 and for microfluidics. 4 Theory of capillary imbibition has been intensively studied since the pioneering works of Bell & Cameron, 5 Lucas 6 and Washburn. 7 They assumed, in agreement with experimental observations, that under the action of capillary effects (Laplace pressure below the interface) a wet front progresses through the sample while saturating the material behind.…”

“…(c) Biporous materials containing 70% (BP70) and 50% (BP50) HEMA. Black line BP70 corresponds to eqn(4) with parameters f = 0.97, k = 4 Â 10 À11 m 2 , % r = 150 mm. Black line BP50 is obtained by assuming that imbibition of the porous skeleton (SP50 matrix) is the kinetically limiting process: eqn (4) is used with parameters: f = 0.76, k = 3 Â 10 À13 m 2 , % r = 160 mm.…”

Hybridization-based DNA biosensing with a limit of detection of 4 fM in 30 s using an electrohydrodynamic concentration module fabricated by grayscale lithography

“…Specifically, 2.5D microchannels are fabricated by direct grayscale lithography (GSL) to produce funnel shaped geometries with non-uniform width and height. GSL has already been used in microfluidics to obtain complex free-standing shapes 28 or design programmable gradients 29 , valves 30 , and model porous systems 31 , but to the best of our knowledge, it has not been applied to design biosensing systems. An LoD of 4 fM in 30 seconds is achieved with these GSL chips.…”