Elephant whiskers on the trunk of Asian elephants go from a stiff, coarse, porous base to thin, dense, and soft tips, forming a functional gradient.[1][3][4] This gradient enables easy contact with objects, reduces whisker wear, and improves tactile perception by encoding full-length contact.[1][5][6] Unlike elephant whiskers, rat and mouse whiskers have a uniformly stiff texture, while domestic cat whiskers show the same stiff-to-soft transition.[1][3][5] The researchers used micro-CT imaging, electron microscopy, mechanical tests, and computer models to characterize the geometry, porosity, and stiffness of the whiskers of young and adult elephants.[3][4] Simulations have shown that the stiffness gradient amplifies vibrotactile signals, allowing elephants to pinpoint the point of contact on each of the roughly 1,000 whiskers on their trunk.[1][3][5] This feature facilitates delicate manipulations, such as picking up a tortilla or peanut without damage.[1][5][6] Functional gradients thus create "material intelligence" to optimize sensitivity without active movement.[3][5]