Dual wettability on diarylethene microcrystalline surface mimicking a termite wing

Abstract

The termite wing has a specific property of wetting in contact with a water droplet: it adsorbs water mist, whereas larger water droplets are bounced on the surface. This is owing to the survival strategy of termites. Here, we reproduce the termite wing's dual wettability by a photoinduced crystal growth technique. Upon UV irradiation to a microcrystalline surface of a mixture of two diarylethenes, two types of needle-shaped crystals of distinctly different sizes are observed to grow. The surface shows behavior akin to the termite wing's dual wettability. The bouncing ability of a water droplet is attributed to the smaller-sized needle crystals, whereas the adhesive property is owing to the larger-sized ones, explaining the microstructures of the termite wing. Considering dissipation energy and adhesion energy, the bouncing ability and dual wettability can be explained theoretically. The surface could potentially be used in water harvesting applications.

Proposal of a Water-repellency Model of Water Strider and Its Verification by Considering Directly Measured Strider Leg-rowing Force

“…Nano-and micro-structures that provide waterrepellent (hydrophobic) surfaces have been realized by various fabrication methods such as photolithography (using photopolymers) [1][2][3], laser direct-writing [4,5], photoinduced crystal growth [6], chemical-base deposition [7][8][9], etching [10], electrospinning [11,12], and membrane casting [13]. Hence, the water-repellency properties exerted by microtextured hydrophobic surfaces of many living things have received considerable attention in the field of biomimetics.…”

“…For example, lotus leaf surface structures show a self-cleaning ability due to their superhydrophobic property (this is called a lotus effect) [14,15], and several studies have mimicked the superhydrophobic property of lotus leaf surfaces [16][17][18][19]. There have also been reports on the development of a surface which has mimicked a rose petal surface (petal effect) [20], a termite wing surface [6], and a porcupinefish skeleton material [21]. Additionally, self-cleaning by biomimetic hydrophobic surfaces has attracted interest in the fields of art and architecture [22].…”

Dust Adhesion Suppression Effect by Meta-material Structure

“…By grasping the actual condition of the deposits, countermeasures and prevention can be taken, leading to a reduction in maintenance work. To solve this problem, there is a metamaterial technology that mimics the shell of a snail, one of the biomimetics [18][19][20][21][22], and has an oil-repellent effect.…”

Component Analysis of Extraneous Stuffs Attached on Measurement Target of Track Irregularity

“…From theses backgrounds, we have been developing the antifouling technology of the measurement target used by metamaterial effect [5][6][7][8][9][10]. There have been many studies on polymer surfaces and water droplets [11][12][13][14][15][16][17][18][19][20][21][22][23][24]. However, the behavior of deposits and the composition of elements on the polymer surface.…”