Laser-Engraved Textiles for Engineering Capillary Flow and Application in Microfluidics

Abstract

Steering capillary flow in textiles is of great significance in developing affordable and portable microfluidics devices. However, owing to the complex fibrous network, it remains a great challenge to achieve capillary flows with precise filling fronts. Here, an in situ laser engraving route is reported to accurately and rapidly etch textiles for manipulating capillary flow. The heterogeneity of the textile structure is enhanced because of the directional spreading of molten fibers polymer under the control of surface energy minimization. The principle of achieved anisotropic wicking of a water droplet in laser-engraved textiles is proposed. This understanding enables patterning the filling front of a fluid in different shapes, including arrow, straight line, diamond, and annulus. Precise capillary flow in textile-based microfluidics can benefit application in many fields, such as chemical analysis, biological detection, materials synthesis, multiliquid delivery. The laser engraving strategy has the advantages of simplicity, full scalability, and time rapidity, which provides an efficient avenue to steer capillary flow in diverse textiles for manufacturing customized microfluidic devices.

Fast Capillary Wicking on Hierarchical Copper Nanowired Surfaces with Interconnected V-Grooves: Implications for Thermal Management

“…Liquid wicking on micro/nanostructured surfaces driven by the capillary pressure has attracted significant attention due to its numerous promising applications in industrial systems such as thermal management, − water harvesting, , and microfluidic − and biomedical devices . The better thermal management in industrial applications, including electronics, aeronautics, and nuclear power, would result in a more efficient and safe design .…”

Reversible Thermally-Responsive Copolymer Valve for Manipulating Water Wicking

“…Wicking is a ubiquitous dynamic wetting process in which capillary force drives liquid flow in porous systems. , With the development of high technology, such as thermal management materials, − lab-on-a-chip , and electronic devices, , the complex and diverse application environment also puts more demands on the innovation of technology. Since wicking possesses miniaturization ability, simple equipment, and does not require external energy supply, it has been widely utilized in phase change boiling heat transfer, − water harvesting in arid environments, , moisture wicking wearable equipment, − micro biochemical testing platforms, and microfluid manipulation equipment. , In particular, wicking phenomena have become the hot direction of microfluidic manipulation technology development, such as precise one-dimensional fluid manipulation, two-dimensional planes for fluid collection, and dynamic liquid filling and mixing . However, few studies have focused on adjustable wicking with changes in the external environment, which is highly desired in advanced technology.…”

Four-dimensional imaging and free-energy analysis of sudden pore-filling events in wicking of yarns

“…Where Washburn, continuum, and pore network models assume a smooth uptake process and approximate the pore-filling processes in a strong simplification, stepwise water uptake via a series of bursts has been recently reported [14], especially in the context of spontaneous imbibition in yarns [15] and textiles [16]. This stepwise uptake process has been disregarded and its apparent effect on the overall wicking dynamics neglected [1,[17][18][19][20][21][22]. Meniscus arrest and stepwise filling at pore scale can in some cases be attributed to pressure distributions pulling water to neighboring pores [23].…”