| 초록 |
We have introduced new applications with one of the well-known extreme wetting property of superhydrophilicity for capillary-induced fold of stiff skin. We provided an interesting mechanical instability of very thin hard skin on soft substrate induced by water droplet. We present an approach to triggering the folding instability of a thin skin on a soft substrate using small mechanical compression in combination with water. We exploit capillary forces in our system where a superhydrophilic stiff skin is formed on the surface of soft poly(dimethylsiloxane) (PDMS) substrates just after oxygen plasma treatment. When a droplet of water is placed on the wrinkled surface under only a small mechanical compressive strain, ≈ -0.01, localized folds abruptly appear around the contact line of the droplet, resulting in spontaneous formation of an array of nanochannels by folds. |
