Toughness of soft-hard composites and Wetting on Textured Substrates

In the first part, after discussing works on nacre, a soft-hard composite found in nature, including a simulation on network mimicking nacre [1-4], we talk on a simple model of spider webs, another example of natural soft-hard structure [5]. We demonstrate that the web network is free of stress concentrations because the radial threads are stronger than the spiral threads. In the second part, after reviewing our works on wetting on textured surfaces [6-8], we discuss penetration into textured surface and instability of a liquid film on textured substrates during spin coating [9,10].