“Liquid diode” with “gating” based on shape memory sponge

Designing Janus Two-Dimensional Porous Materials for Unidirectional Transport: Principles, Applications, and Challenges

“…Song et al fabricated a smart Janus sponge consisting of a superhydrophilic sponge and a hydrophobic shape-memory sponge. With a fixed hydrophobic layer thickness of 2.5 mm, the Janus sponge presented a constant hydrostatic pressure with varying hydrophilic sponge thickness from both directions (Figure b) …”

“…(b) Effects of hydrophilic layer thickness on unidirectional transport. Reproduced with permission from ref . Copyright 2022, Springer.…”

“…With a fixed hydrophobic layer thickness of 2.5 mm, the Janus sponge presented a constant hydrostatic pressure with varying hydrophilic sponge thickness from both directions (Figure 4b). 52 2.2.3. Pore Structures.…”

“…A thin hydrophobic layer ensures that droplets reach the hydrophilic layer by overcoming the resistance. Electrospinning is a widely employed technique for fabricating fibrous Janus membranes, allowing for the facile adjustment of the thickness of hydrophobic and hydrophilic layers. , For example, Pi et al constructed Janus membranes with adjustable thicknesses and ratios of hydrophobic/hydrophilic layers by tuning the electrospinning time. Unidirectional transport can be achieved within an optimal electrospinning time range, facilitating the movement of water droplets from the hydrophobic side to the hydrophilic side.…”

Adaptive IR- and Water-Gating Textiles Based on Shape Memory Fibers

“…SMPs change the elastic modulus according to the stimulus; thus, they can memorize a permanent shape while maintaining a temporary shape. , SMPs have the advantages of facile shaping, high shape stability, low cost, lightweight, and biocompatibility; therefore, they have many potential applications in sensors, , actuators, and medical devices . However, SMPs have rarely been used in the field of wearable textiles because of their relatively weak mechanical properties , and extreme fabrication conditions such as hot extrusion or melt molding. , In addition, SMPs are intrinsically hydrophobic or hydrophilic and do not present both characteristics at the same time; therefore, it is difficult to obtain directional water transportation from the hydrophobic to hydrophilic side using the SMPs on their own . Porous SMP fibers can be fabricated by a nonsolvent-induced phase separation, which was suggested to prepare porous SMP films with excellent thermal insulation performance, but the practical application of a porous hairy structure of SMP films is limited due to their relatively thick structures including long SMP hairs .…”