The turtle shell is an amazing structure optimized through the long-term evolution by nature.This paper reports the experimental study on the mechanical property at different levels and locations,and the microstructure of the shell from Trachemys scripta(Red-ear turtle) living in South China.
We report a novel oscillatory behavior of a sessile droplet on a hydrophobic surface. The droplet was placed on an electrode with a hydrophobic surface and close to, but not touching, a second needle-like electrode. The change in the contact angle was observed only when the droplet oscillated. In a traditional electro-wetting experiment, however, the contact angle decreased immediately when an alternating current electric field was applied. In addition, the non-contact mode gave rise to a true sessile condition of the droplet, whose oscillation amplitude was not linearly proportional to the driving voltage but reached a maximum value.
